A prospectus supplement will describe the specific types, amounts, prices and detailed terms of any of these offered securities.

RISK FACTORS

An investment in our securities involves a high degree of risk. Before making an investment decision you should carefully read and consider the risks described below, together with all of the other information included or incorporated by reference in this prospectus, including, without limitation, the risk factors in the section entitled “Risk Factors” in our most recent Annual Report on Form 10-K, and Quarterly Reports on Form 10-Q, which areis on file with the SEC. If any of the risks listed in our most recent Annual Report on Form 10-K or Quarterly Reports on Form 10-Q or any of the following risks actually occur, our business, financial condition, and/or results of operations could suffer. In that case, the market price of our Class A common stock offered by this prospectus could decline, and you may lose all or part of your investment. You should read the section entitled “Special Note Regarding Forward-Looking Statements” above for a discussion of what types of statements are forward-looking statements, as well as the significance of such statements in the context of this prospectus. Additional risks and uncertainties that we do not presently know or that we currently deem immaterial may also have a material adverse effect on our business.

USE OF PROCEEDSThe issuance of shares of Class A common stock upon conversion of our outstanding convertible notes, including the Notes, and exercise of our outstanding warrants could substantially dilute your investment and could impede our ability to obtain additional financing.

Unless otherwise specifiedOur outstanding convertible notes, including the Notes, are convertible into, and our outstanding warrants are exercisable for, shares of our Class A common stock and give the holders an opportunity to profit from a rise in a prospectus supplement accompanying this prospectus, we currently intend to use the net proceeds from the salemarket price of our Class A common stock. Conversion or exercise thereof will result in dilution of the securities offered under this prospectus for general corporate purposes, which may include additionsequity interests of our shareholders. In particular, the conversion price of the Notes is subject to working capital, financing of capital expenditures, repayment of existing or future indebtedness,adjustment and future acquisitions and strategic investment opportunities. Pending any use, as describeda decrease in the applicable prospectus supplement, we plan to invest the net proceedsconversion price would result in short-term, investment grade, interest-bearing securities.

PLAN OF DISTRIBUTION

We may sell the securities being offered by this prospectus separately or together through anymore shares of Class A common stock becoming issuable upon conversion of the following methods:

We may also issue securities upon exercise of warrants or as a dividend or distribution. We reserve the right to sell securities directly to investorsdownward pressure on our own behalf in those jurisdictions where we are authorized to do so.

We may distribute the securities from time to time in one or more transactions:

Direct Sales and Sales through Agents

We may directly solicit offers to purchase the securities offered by this prospectus. Agents designated by us from time to time may solicit offers to purchase the securities. We will name any agent involved in the offer or sale of the securities and set forth any commissions payable by us to an agent in the applicable prospectus supplement. Unless otherwise indicated in the applicable prospectus supplement, any agent will be acting on a best efforts basis for the period of his or her appointment. Any agent may be deemed to be an “underwriter” of the securities as that term is defined in the Securities Act of 1933, as amended (the “Securities Act”).

Sales Through Underwriters or Dealers

If we use an underwriter or underwriters in the sale of securities, we will execute an underwriting agreement with the underwriter or underwriters at the time we reach an agreement for sale. We will set forth in the applicable prospectus supplement the names of the specific managing underwriter or underwriters, as well as any other underwriters, and the terms of the transactions, including compensation of the underwriters and dealers. This compensation may be in the form of discounts, concessions or commissions. The maximum underwriting compensation for any offering under the registration statement to which this prospectus relates may not exceed 8% of the offering proceeds. Underwriters and others participating in any offering of the securities may engage in transactions that stabilize, maintain or otherwise affect the price of our Class A common stock. We have no control over whether the securities.holders will exercise their right to convert their convertible notes or exercise their warrants. We will describecannot predict the market price of our Class A common stock at any future date, and therefore, we are unable to accurately forecast or predict with any certainty the total amount of these activitiesshares that may be issued under the Notes and outstanding warrants. However, we have estimated the number of Class A common stock that may be issued under the Notes in the applicable prospectus supplement.future to be approximately 62.8 million shares and under outstanding warrants (assuming that only warrants with an exercise price at or below $3.10 will be exercised) to be approximately 9.4 million shares. The actual number of shares to be issued cannot be precisely determined.

If a dealer is used in the saleholders of the securities,Notes do not convert their Notes into shares of Class A common stock and we or an underwriterare unable to force them to convert, we will sell securities to the dealer, as principal. The dealer may then resell the securities to the publichave a balance outstanding at varying prices to be determined by the dealer at the time of resale. The applicable prospectus supplement will set forth the namematurity of the dealer and the terms of the transactions.Notes.

The Notes are convertible into shares of our Class A common stock. Note holders are allowed to convert them into shares of Class A common stock at any time. We may directly solicit offersalso will have the ability to purchaseforce Note holders to convert upon the securities, andoccurrence of a certain event. However, we may sell directly to institutional investors or others. These persons may be deemed to be underwriters withindo not expect that Note holders will convert them voluntarily unless the meaning of the Securities Act with respect to anyshares they receive upon conversion are either registered for resale of the securities. The applicable prospectus supplement will describe the terms of any direct sales, including the terms of any bidding or auction process.

Agreements we enter into with agents, underwriters and dealers may entitle them to indemnification by us against specified liabilities, including liabilities under the Securities Act or eligible to contribution by usbe resold under Rule 144 promulgated under the Securities Act (“Rule 144”). Further, our ability to payments theyforce Note holders to convert them is subject to the satisfaction of certain conditions and we may be requiredunable to makesatisfy these conditions.

In the event there is a balance outstanding at maturity, we would seek to refinance the remaining balance outstanding at that time from either: (i) refinancing of the obligation with the Note holders, (ii) an offering of securities, or (iii) common stock warrant exercises, including by reducing the exercise price of common stock warrants to induce conversion. No assurances can be given that should a balance remain on the Notes at maturity we will be successful in respect of these liabilities. The applicable prospectus supplementmeeting the obligation under the Notes. Should we determine to seek capital from a securities offering, it will describe the terms and conditions of indemnification or contribution.be dilutive to shareholders.

Delayed Delivery ContractsThe terms of some of our outstanding securities and certain transaction documents we have entered into with investors participating in our past offerings could impede our ability to enter into certain transactions or obtain additional financing and could result in our paying premiums or penalties to the holders of the Notes and outstanding warrants.

We may authorize underwriters, dealers and agents to solicit offers by certain institutional investors to purchase offered securities under contracts providing for payment and delivery on a future date specified in the applicable prospectus supplement. The applicable prospectus supplement will also describe the public offering price for the securities and the commission payable for solicitationterms of these delayed delivery contracts. Delayed delivery contracts will contain definite fixed price and quantity terms. The obligations of a purchaser under these delayed delivery contracts will be subject to only two conditions:

“At the Market” Offerings

We may from time to time engage a firm to act as our agent for one or more offeringssome of our securities. We sometimes refer to this agent as our “offering agent.” If we reach agreement with an offering agent with respect to a specific offering,outstanding securities, including the numberNotes and some of securities and any minimum price below which sales may not be made, then the offering agent will tryour outstanding series of warrants to sell such securities on the agreed terms. The offering agent could make sales in privately negotiated transactions or using any other method permitted by law, including sales deemed to be an “at the market” offering as defined in Rule 415 promulgated under the Securities Act, including sales made directly on any national exchange upon which our securities are listed, or sales made to or through a market maker other than on an exchange. The offering agent will be deemed to be an “underwriter” within the meaning of the Securities Act with respect to any sales effected through an “at the market” offering.

Market Making, Stabilization and Other Transactions

To the extent permitted by and in accordance with Regulation M promulgated under the Securities Exchange Act of 1934, as amended (the “Exchange Act”), in connection with an offering, an underwriter may engage in over-allotments, stabilizing transactions, short covering transactions and penalty bids. Over-allotments involve sales in excess of the offering size, which creates a short position. Stabilizing transactions permit bids to purchase the underlying security so long as the stabilizing bids do not exceed a specified maximum. Short covering transactions involve purchases of the securities in the open market after the distribution is completed to cover short positions. Penalty bids permit the underwriters to reclaim a selling concession from a dealer when the securities originally sold by the dealer are purchased in a covering transaction to cover short positions. Those activities may cause the price of the securities to be higher than it would be otherwise. If commenced, the underwriters may discontinue any of these activities at any time.

To the extent permitted by and in accordance with Regulation M promulgated under the Exchange Act, any underwriters who are qualified market makers on any national exchange upon which our securities are listed may engage in passive market making transactions in the securities on such exchange during the business day prior to the pricing of an offering, before the commencement of offers or sales of the securities. Passive market makers must comply with applicable volume and price limitations and must be identified as passive market makers.

In general, a passive market maker must display its bid at a price not in excess of the highest independent bid for such security; if all independent bids are lowered below the passive market maker’s bid, however, the passive market maker’s bid must then be lowered when certain purchase limits are exceeded.

DESCRIPTION OF CLASS A COMMON STOCK

Our authorized common stock consists of 150,000,000 shares of Class A common stock, par value $.0001 per share. Asprohibit us from entering into a “fundamental transaction” (as defined in the Notes and such warrants) (including generally, a merger, sale of July 10, 2017, there were 7,480,906all or substantially all of our assets, or permitting a purchase tender or exchange offering resulting in a person or group of persons owning at least 50% of the outstanding shares of our Class A common stock) unless, among other things, the successor resulting from the fundamental transaction assumes all of our obligations under the Notes, the applicable warrants and the associated transaction documents. The terms of the transaction documents we have entered into with investors participating in our past offerings also contain restrictions on our ability to conduct future securities offerings and incur additional debt.

Further, the Notes and our outstanding warrants require us to deliver the number of shares of our Class A common stock outstanding. Althoughissuable upon conversion or exercise within a specified time period. If we believe the following summary description of our Class A common stock set forth below is accurate, our articles of incorporation and our bylaws covers all material provisions affecting the rights of holders of our Class A common stock. This summary is not intendedare unable to be complete and is qualified by reference to the provisions of applicable law and to our articles of incorporation and bylaws.

Voting Rights

Each holder of shares of Class A common stock is entitled to one vote for each share held on all matters submitted to a vote of shareholders. There are no cumulative voting rights. All holders of shares of Class A common stock vote as a single group on all matters that are submitted to the shareholders for a vote. Accordingly, holders of a majority ofdeliver the shares of Class A common stock entitledwithin the timeframe required, we may be obligated to vote in any electionreimburse the holder for the cost of directors may elect all of the directors who stand for election. Our entire board of directors stands for election each year. A required number of shareholders having the minimum number of votes that would be necessary to authorize or take action at a meeting at which all ofpurchasing the shares entitled to vote thereon were present and voted may consent to an action in writing and without a meeting under certain circumstances.

Dividends and Liquidation

Subject to any preferential rights of any outstanding shares of preferred stock, shares ofour Class A common stock are entitledin the open market or pay them the profit they would have realized upon the conversion or exercise and sale of such shares.

We may also be obligated to receive dividends, if any, as may be declared by our boardredeem the Notes at a premium upon the occurrence of directors out of legally available funds. In thean event of default (as defined in the Notes) or a liquidation, dissolution or winding upchange of control (as defined in the Notes). Some of our company,outstanding warrants also contain features that may require us to repurchase such warrants upon the sharesoccurrence of Class A common stock are entitled to our assets remaining after the payment of all of our debts and other liabilities, including preferential payments made to holders of any outstanding shares of preferred stock. Holders of shares of Class A common stock have no preemptive, subscription or redemption rights, and there are no redemption or sinking fund provisions applicable to the shares of Class A common stock.

Anti-Takeover Effects of Our Articles of Incorporation and Bylaws

The following provisions, which are contained in our articles of incorporation or bylaws, could have the effect of delaying, deferring or preventing a change in control of our company.

Our articles of incorporation and bylaws provide that our board may consist of any number of directors, which may be fixed from time to time by our board. Newly created directorships resulting from any increase in our authorized number of directors may be filled by the affirmative vote of a majority of the directors then in office or by an election at an annual meeting or special meeting of shareholders called for that purpose, and any vacancies on our board resulting from death, resignation, retirement, disqualification, removal from office or other cause may be filled a majority of our board then in office, even if less than a quorum is remaining in office.

Our bylaws require advance notice by a shareholder of any proposal to be brought before an annual meeting of shareholders by a shareholder, including any nomination for election of directors by any shareholder entitled to vote for the election of directors at the meeting. Our bylaws also provide that no shareholder proposal may be considered at a meeting of our shareholders unless the proposal relates to a matter on which a shareholder vote is required by our charter, bylaws or by applicable law.

Our board of directors has the power to issue preferred stock with designations, preferences, limitations and relative rights determined by the board of directors without any vote or action by shareholders. The issuance of preferred stock or of rights to purchase preferred stock could have the effect of making it more difficult for a third party to acquire Real Goods Solar, or of discouraging a third party from attempting to acquire Real Goods Solar.

Subject to repeal or change by action of our shareholders, our board may amend, supplement or repeal our bylaws or adopt new bylaws.

Registration Rightscontrol.

In connection withaddition to the closing of its June 3, 2013 private placement, Real Goods Solarforegoing, we may be obligated to pay cash penalties under the registration rights agreement we have entered into a Registration Rights Agreement with the investors to have their shares of Real Goods Solar Class A common stock purchased in the private placement and issuable upon exercise of warrants purchased in the private placement registered with the SEC for public resale under the Securities Act. On June 20, 2013, Real Goods Solar filed a registration statement on Form S-3 to register these shares pursuant to the terms of this RegistrationApril 2018 Offering (the “Registration Rights Agreement. The SEC declaredAgreement”). For example, if the registration statement effective on July 3, 2013. Real Goods Solar is required to maintain the effectiveness of the registration statement until the earlier to occur of (a) the fifth anniversary of the effectiveness of the registration statement, or (b) the date on which all of the registrable securities covered bybe filed under the Registration Rights Agreement have been sold or transferred in a manner that they may be resold without subsequent registration under the Securities Act.

The Registration Rights Agreement further provides that in the event that (a) the registration statement ceases to be effective and available to the investorsselling shareholders under certain circumstances, or (b) Real Goods Solar fails to timely file all reports required to be filed under the Exchange Act other than Current Reports on Form 8-K, Real Goods Solar shallwe must pay to the holders of registrable securities,selling shareholders, on the occurrence of each such event and on each monthly anniversary thereofevery 30th day thereafter until the applicable event is cured, an amount in cash equal to 1.0% of the aggregate purchase price paid byoriginal principal amount under the Notes on the date of issuance. On April 27, 2018, we filed a Registration Statement on Form S-3 to register for resale an investor multiplied by the percentageaggregate of such investor’s registrable securities that are not covered by the registration statement, up to a maximum51,038,634 of 10.0% of such aggregate purchase price. The foregoing description is subject to the terms and conditions identified in the Registration Rights Agreement.

On November 15, 2013, Real Goods Solar entered into an Underwriting Agreement with an underwriter in connection with a registered public offering. Pursuant to the Underwriting Agreement, Real Goods Solar has agreed to file a registration statement covering the issuance of the shares of Real Goods Solar Class A common stock underlyingissuable upon conversion of the warrants issuedNotes and exercise of the Series Q warrants. The SEC declared the registration statement effective on May 4, 2018.

The payments described above we may be obligated to make may adversely affect our results of operations.

DESCRIPTION OF THE TRANSACTION

January 2018 Offering (January 2018 Placement Agent Warrants)

On January 4, 2018, we closed the January 2018 Offering. Under the terms of the engagement letter dated December 13, 2017 between us and WestPark Capital, Inc. (“WestPark”) and in connection with WestPark’s acting as placement agent in the offering on November 20, 2013January 2018 Offering, we issued and sold to cause such registration statementWestPark for a sum of $100 a warrant to be declared effective before the time the warrants become exercisable and to remain effective through the earlier of (a) the expiration date of the warrants and (b) the date on which all of the warrants shall have been exercised in full. The warrants are exercisable at any time on or after the one year anniversary of their original issuance and at any time up to the date that is five and one-half years after the date of their original issuance. If a registration statement registering the issuance of thepurchase 128,000 shares of Real Goods Solar Class A common stock underlyingat an exercise price of $1.47, and WestPark transferred such warrant to four of its employees (the “January 2018 Placement Agent Warrants”). The current holders of the warrantsJanuary 2018 Placement Agent Warrants are listed in the selling shareholder table included in the section entitled “SELLING SHAREHOLDERS.”

Description of the January 2018 Placement Agent Warrants

The January 2018 Placement Agent Warrants became exercisable six months after issuance and will remain exercisable until the fifth anniversary of such date. The initial and current exercise price of the January 2018 Placement Agent Warrants is $1.47 per share, subject to adjustments for stock splits and similar events (but not for subsequent issuances of securities; nor is the exercise price subject to a reset). The holder of the January 2018 Placement Agent Warrants may elect to exercise them through a cashless exercise at any time, regardless of whether the shares of Class A common stock issuable upon exercise are covered by a registration statement under the Securities Act, is not effective or available and an exemption from registration under the Securities Act is not available for the issuance of such shares, if the holder, in its sole discretion, elects to exercise a warrant, the holder shall do so through a cashless exercise, in which case the holder wouldwill receive upon such exercise the “net number” of shares of Real Goods Solar Class A common stock determined according to the formula set forth in the warrant.January 2018 Placement Agent Warrant and we will not receive the exercise price.

A holder may not exercise a Registration Rights Agreement with the investors to have theirJanuary 2018 Placement Agent Warrant and we may not issue shares of Real Goods Solar Class A common stock purchasedunder a January 2018 Placement Agent Warrant if, after giving effect to the exercise or issuance, the holder together with its affiliates would beneficially own in excess of 4.99% of the outstanding shares of Class A common stock. At the holder’s option, the cap may be increased or decreased to any other percentage not in excess of 9.99%, except that any increase will not be effective until the 61st day after notice to us.

A holder of a January 2018 Placement Agent Warrant is entitled to acquire options, convertible securities or rights to purchase our securities or property granted, issued or sold pro rata to the holders of our Class A common stock on an “as if exercised for Class A common stock” basis. A holder of a January 2018 Placement Agent Warrant is entitled to receive any non-cash dividend or other distribution of our assets (or rights to acquire its assets), at any time after the issuance of the January 2018 Placement Agent Warrants, on an “as if exercised for Class A common stock” basis.

The January 2018 Placement Agent Warrants prohibit us from entering into transactions constituting a “fundamental transaction” (as defined in the January 2018 Placement Agent Warrants) unless the successor entity assumes all of our obligations under the January 2018 Placement Agent Warrants in a written agreement approved by the “required holders” of our Series O Warrant issued in our January 2018 Offering. The definition of “fundamental transactions” includes, but is not limited to, mergers, a sale of all or substantially all of our assets, certain tender offers and other transactions that result in a change of control.

April 2018 Offering (Notes, Series Q Warrants and April 2018 Placement Agent Warrants)

On April 9, 2018, we closed the April 2018 Offering, a private placement of Notes and issuable upon exerciseSeries Q warrants with two unaffiliated institutional and accredited investors (the “Investors”), in which we issued and sold to the Investors (i) $10.75 million in principal amount and $10 million funding amount (reflecting an original issue discount of warrants purchased$750,000) of convertible notes due April 9, 2019, consisting of (A) two Series A Notes in the private placement registeredaggregate principal amount of $5,750,000 in consideration for aggregate cash payments of $5,000,000, (B) two Series B Notes in the aggregate principal amount of $5,000,000 for consideration consisting of two secured promissory notes, each issued and payable by an Investor, in the aggregate principal amount of $5,000,000 (each, an “Investor Note”), and (ii) Series Q warrants to purchase up to 9,126,984 shares of our Class A common stock, under the terms of the Securities Purchase Agreement, dated March 30, 2018, among us and the Investors (as amended, the “Purchase Agreement”). The Notes are convertible into, and the Series Q warrants are exercisable for, shares of our Class A common stock.

The Notes and the Series Q warrants were issued in physical form separately from each other and may be transferred separately at any time. The Notes and the Series Q warrants are not listed on any national securities exchange or other trading market, and no trading market for the Notes and the Series Q warrants is expected to develop.

Under the terms of the engagement letter dated January 29, 2018 we entered into with WestPark in connection with the SECApril 2018 Offering, we issued and sold to WestPark for public resalea sum of $100 a warrant to purchase 730,160 shares of Class A common stock at an initial exercise price of $1.12, and WestPark transferred such warrant to four of its employees (the “April 2018 Placement Agent Warrants” and, together with the January 2018 Placement Agent Warrants, collectively, the “Placement Agent Warrants”). The current holders of the April 2018 Placement Agent Warrants are listed in the selling shareholder table included in the section entitled “SELLING SHAREHOLDERS.”

Description of the Notes

Principal Amount; Maturity Date; Interest

The aggregate original principal amount of the Series A Notes was $5,750,000 and the Series B Notes was $5,000,000. As of September 6, 2018, the aggregate principal amount of 3,151,544 of the Series B Notes constitutes Restricted Principal (as defined in the Series B Notes). If an Investor prepays any amount under such Investor’s Investor Note, an equal amount of the Restricted Principal becomes unrestricted principal under such Investor’s Series B Note. In lieu of initially receiving any original issue discount on the Series B Notes, the Series B Notes accrue an “Additional OID Amount” (as defined in the Series B Notes) based upon the portion of the principal of the Series B Notes that becomes unrestricted from time to time, pro rata, which, in the aggregate would result in up to $750,000 of Additional OID Amount payable under the Securities Act.Series B Notes if all of the principal under the Series B Notes becomes unrestricted.

All amounts outstanding under the Notes mature and will be due and payable on April 9, 2019, the one-year anniversary of the issuance of the Notes. We are not required to amortize the Notes. The Notes do not incur interest other than upon the occurrence of an event of default, in which case the Notes bear default interest at 18% per year.

Conversion of the Notes

The Notes are convertible at any time, at the option of the holders, into shares of Class A common stock at a conversion price. The initial fixed conversion price was $1.26 per share, subject to reduction, as described below, and adjustment for stock splits, stock dividends, and similar events. On July 31, 2014, Real Goods Solar filed a registration statement on Form S-39, 2018, the conversion price was automatically reset to register these shares$0.3223 pursuant to the terms of this Registration Rights Agreement. The SEC declared the registration statement effective onNotes. On August 11, 2014. Real Goods Solar is required29, 2018, we agreed with the Note holders to maintainreduce the effectivenessconversion price further to $0.3067.

Following an event of default under the Notes, during a specified time period, a Note holder may convert a Note at an Alternate Conversion Price and at a 125% premium. “Alternate Conversion Price” means the greater of (i) a floor price of $0.194, and (ii) the lower of (A) the conversion price, and (B) 85% of the registration statement untilprice computed as the earlier to occurquotient of (a)(1) the fifth anniversarysum of the effectivenessVWAP (a volume-weighted average price of our Class A common stock, as defined in the Notes) of the Class A common stock for each of the two trading days with the lowest VWAP of the Class A common stock during the 20 consecutive trading day period ending and including the date of the delivery by the Note holder of a conversion notice, divided by (2) two.

We have the right to require Note holders to convert all, or any part of, their Notes if at any time (i) the VWAP of the Class A common stock exceeds 200% of the conversion price for 10 consecutive trading days, and (ii) no Equity Conditions Failure (as defined in the Notes) then exists. However, our ability to force a holder to convert its Notes is limited to each Note holder’s pro rata amount of an amount equal to 20% of the aggregate dollar trading volume of the Class A common stock during the 20 consecutive trading day period before the date we provide notice of mandatory conversion to Note holders.

Equity Conditions

The Notes require that certain Equity Conditions (as defined in the Notes) are met to allow us to take certain actions. Generally, the Equity Conditions include, but are not limited to, requirements that (i) holders of Notes and Series Q warrants may resell shares of Class A common stock issuable upon conversion and exercise of the Notes and the Series Q warrants under an effective registration statement or (b)under Rule 144; (ii) the dateClass A common stock is listed on which allan Eligible Market (as defined in the Notes); (iii) certain stock price and volume requirements are met; (iv) there is no event of default under the Notes; and (v) we have obtained shareholder approval of the registrable securities covered byissuance of shares of Class A common stock upon conversion of the Registration Rights Agreement have been sold or transferred in a manner that they may be resold without subsequent registrationNotes and exercise of the Series Q warrants at conversion and exercise prices below the initial conversion price of the Notes and the initial exercise price of the Series Q warrants, as required under Nasdaq Rule 5635(d), which we obtained on June 21, 2018.

Reduction of the Securities Act.Conversion Price

The Registration Rights Agreement further provides that in the event that (a) the registration statement ceases to be effective and available to the investors under certain circumstances, or (b) Real Goods Solar fails to timely file all reports required to be filed under the Exchange Act other than Current Reports on Form 8-K, Real Goods Solar shall pay to the holders of registrable securities, on the occurrence of each such event and on each monthly anniversary thereof until the applicable event is cured, an amount in cash equal to 1.0%conversion price of the aggregate purchase price paid by an investor multiplied by the percentage of such investor’s registrable securities that are not covered by the registration statement, up to a maximum of 10.0% of such aggregate purchase price. The foregoing descriptionNotes is subject to the terms and conditions identified in the Registration Rights Agreement.reduction as described below.

On February 23, 2015, Real Goods Solar entered into a Securities Purchase Agreement with an investor

The conversion price may also be reduced in connection with our failure to pay the redemption price in a registered public offering. Pursuanttimely manner, as described below.

Redemption of the Notes

At any time after the later of (i) 15 days after the Applicable Date (as defined below) and (ii) the date no Equity Conditions Failure (as defined in the Notes) exists, we will have the right to redeem all, but not less than all, of the Securities Purchase Agreement, Real Goods Solar must use reasonable best effortsNotes in cash at a price equal to maintain a registration statement effective registering(A) if on or before October 9, 2018, 120% or (B) if after such date, 125%, in each case, of the Registerablegreater of (1) the amount being redeemed, and (2) the product of (x) the amount being redeemed divided by the conversion price, multiplied by (y) the greatest closing price of the Class A common stock on any trading day during the period commencing on the date immediately preceding the date on which we provided notice of such redemption and ending on the trading day immediately before the date we make the entire redemption payment. “Applicable Date” means the earlier of (i) the first date on which the resale by the Investors of all the Registrable Securities (as defined in the Registration Rights Agreement) required to be included on the initial registration statement under the Registration Rights Agreement is declared effective by the SEC (and each prospectus contained therein is available for use on such date), and (ii) the first date on which all of the Registrable Securities Purchase Agreement)are eligible to be resold by the Investors under Rule 144, subject to certain conditions.

If we consummate a Subsequent Placement (as defined in the Notes), subject to some exceptions, a Note holder will have the right to require that we redeem, in whole or in part, a portion of the amounts owed by us to such holder under a Note equal to such holder’s pro rata share of 37.5% of the gross proceeds from such Subsequent Placement in cash at a price calculated as described in the paragraph above.

A Note holder may also require us to redeem all or a portion of its Note in connection with a transaction that results in a Change of Control (as defined in the Notes) and upon the occurrence of an event of default, as described below.

If we do not pay the redemption price in a timely manner, Note holders have the option to cancel such redemption and the principal amount of each Note will then be increased by an amount equal to the difference between (i) the applicable redemption price minus (ii) the principal portion of the amount subject to redemption. In addition, the conversion price will be automatically adjusted with respect to each conversion effected thereafter by a Note holder to the lowest of (i) the conversion price, (ii) the greater of (A) $0.194 and (B) 75% of the lowest closing bid price of the Class A common stock during the period beginning on and including the date on which the applicable redemption notice is delivered to us and ending on and including the date on which the applicable redemption notice is voided, and (iii) the greater of (A) $0.194 and (B) 75% of the quotient of (I) the sum of the five lowest VWAPs of the Class A common stock during the 20 consecutive trading day period ending and including the applicable conversion date divided by (II) five.

Events of Default

The Notes contain customary events of default, including but not limited to: (i) failure to file or have declared effective by the SEC the applicable registration statement required by the Registration Rights Agreement within certain time periods or failure to keep the registration statement effective as required by the Registration Rights Agreement, (ii) failure to maintain the listing of the Class A common stock, (iii) failure to make payments when due under the Notes, (iv) breaches of covenants, and (iv) bankruptcy or insolvency.

The occurrence of an event of default under the Notes will trigger default interest and will cause an Equity Condition Failure, which may mean that we will be unable to force mandatory conversion of the Notes and that Investors may not be required to prepay their Investor Notes under a mandatory prepayment event.

Following an event of default, Note holders may require us to redeem all or any portion of their Notes in cash at a conversion price equal to the greater of (i) 125% of the amount to be redeemed, and (ii) the product of (A) the amount to be redeemed divided by the conversion price, multiplied by (B) the product of (x) 125% multiplied by (y) the greatest closing sale price of the Class A common stock on any trading day during the period commencing on the date immediately preceding such event of default and ending on the date we make the entire redemption payment.

We must immediately redeem the Notes in cash in an amount equal to 125% multiplied by the amount to be redeemed upon the occurrence of a Bankruptcy Event of Default (as defined in the Notes).

Fundamental Transactions and Change of Control

The terms of the Notes prohibit us from entering into transactions constituting a Fundamental Transaction (as defined in the Notes) unless the successor entity, which must be a publicly traded corporation whose common stock is quoted on or listed for as longtrading on an Eligible Market (as defined in the Notes), assumes all of our obligations under the Notes and the other transaction documents in a written agreement approved by each Note holder. The definition of Fundamental Transactions includes, but is not limited to, mergers, a sale of all or substantially all of our assets, certain tender offers and other transactions that result in a change of control.

Further, in connection with a Change of Control (as defined in the Notes), upon request of a Note holder, we must redeem all or any portion of such holder’s Note(s) in cash at a 125% premium in an amount calculated pursuant to a formula set forth in the Notes. The definition of Change of Control is generally the same as the definition of Fundamental Transaction but excludes certain types of Fundamental Transactions.

Beneficial Ownership Limitation

A holder may not convert a Note and we may not issue shares of Class A common stock upon conversion of a Note, if, after giving effect to the conversion, a holder together with its “attribution parties,” would beneficially own in excess of 4.99% or 9.99%, as elected by each Investor at closing, of the outstanding shares of our Class A common stock. At each holder’s option, the cap may be increased or decreased to any other percentage not in excess of 9.99%, except that any increase will not be effective until the 61st day after notice to us.

Purchase Rights; Distributions of Assets

The Note holders are entitled to acquire options, convertible securities or rights to purchase our securities or property granted, issued or sold pro rata to the holders of our Class A common stock on an “as if converted into Class A common stock” basis. The Note holders are entitled to receive any dividend or other distribution of our assets (or rights to acquire our assets), at any time after the issuance of the Notes, on an “as if converted into Class A common stock” basis.

Covenants

We agreed to certain negative covenants in the Notes, under which we have agreed not to, and to cause our subsidiaries not to, among other things: (i) incur or guarantee, assume or suffer to exist any indebtedness, other than certain permitted indebtedness, (ii) allow or suffer to exist any mortgage, lien, pledge, charge, security interest or other encumbrance upon or in any property or assets of ours or any of our subsidiaries other than certain permitted liens, (iii) redeem, defease, repurchase, repay or make any payments in respect of, by the payment of cash or cash equivalents all or any portion of any indebtedness other than the Notes if at the time such payment is due or is otherwise made or, after giving effect to such payment, an event of default under the Notes has occurred and is continuing, (iv) redeem, repurchase or declare or pay any cash dividend or distribution on any of our capital stock, (v) sell, lease, license, assign, transfer, spin off, split off, close, convey or otherwise dispose of any material assets or rights, subject to certain exceptions, (vi) permit any of our indebtedness to mature or accelerate before the maturity date of the Notes, (vii) make any changes in the nature of our business nor modify our corporate structure or purpose, (viii) enter into transactions with affiliates, subject to certain exceptions, or (ix) issue any Notes or any other securities that would cause a breach or default under the Notes or the Series A Warrants,Q warrants.

We also agreed to certain affirmative covenants in the Notes, pursuant to which we agreed to and will cause each of our subsidiaries to, among other things: (i) maintain and preserve ours and its existence, rights and privileges, and become or remain duly qualified and in good standing in each jurisdiction in which the character of the properties owned or leased or in which the transaction of our business makes such qualification necessary, (ii) maintain and preserve all properties which are necessary or useful in the proper conduct of our business in good working order and condition, ordinary wear and tear excepted, and comply at all times with the provisions of all leases to which we are a party as lessee or under which we occupy property, so as to prevent any loss or forfeiture thereof or thereunder, (iii) maintain all intellectual property rights that are necessary or material to the conduct of our business, (iv) maintain certain insurance coverage, (v) at any time at least $1,000,000 in aggregate principal amount of Notes remains outstanding, maintain Available Cash (as defined in the Notes) as of each fiscal quarter equal to or exceeding $750,000, and (vi) make quarterly announcements of operating results.

Other Terms Specific to the Series B Warrants,Notes

If an Investor Note is pledged, assigned or transferred to any person other than us without the prior written consent of the applicable Investor, including by contract, operation of law, court order or otherwise (each, a “Prohibited Transfer”) or if any provision of an Investor Note is prohibited by law or otherwise determined to be invalid or unenforceable by a court of competent jurisdiction or other similar authority, in each case, (i) such Investor Note will be deemed paid in full and will be null and void, and (ii) 75% of the remaining Restricted Principal of the applicable Series B Note will be automatically cancelled (with the remaining 25% of the Restricted Principal becoming unrestricted principal).

The Restricted Principal of the Series C WarrantsB Notes are subject to offset under certain circumstances, as further described below. Upon any offset, the Restricted Principal under a Series B Note will automatically and simultaneously be reduced, on a dollar-for-dollar basis, in an amount equal to the Series D Warrants issued pursuant toprincipal amount of an Investor’s Investor Note that is cancelled and offset.

Under the terms of the Securities Purchase Agreement are outstanding.Series B Notes, we granted a security interest to each Investor in such Investor’s Investor Note to secure our obligations under the applicable Series B Note. Each Investor perfected its security interest by taking possession of such Investor’s Investor Note at the closing.

On June 26, 2015, Real Goods Solar entered into a Securities Purchase Agreement with several investors in connection with a registered public offering. Pursuant toNumber of Shares Issuable Upon Conversion of the Securities Purchase Agreement, Real Goods Solar must use reasonable best efforts to maintain a registration statement effective registering the Registerable SecuritiesNotes

As of September 6, 2018, (i) an aggregate principal amount of $5,693,700 and an aggregate Additional Amount (as defined in the Securities Purchase Agreement) for as long asSeries A Notes) of $13,429,248 under the Series F WarrantsA Notes, and (ii) an aggregate principal amount of $1,036,556 and an aggregate Additional Amount (as defined in the Series B Notes) of $3,973,630 under the Series B Notes, have been converted into shares of Class A common stock. As of September 6, 2018, an aggregate of $5,474,662 was outstanding under the Series A Notes and an aggregate of $7,469,635 was outstanding under the Series B Notes.

The following table sets forth the total number of shares of Class A common stock that would be issued pursuant to the termsNote holders if an aggregate amount of $12,944,297 (which includes all principal and all possible original issue discount amounts and Additional Amounts that may accrue under the Notes as of September 6, 2018) is converted into shares of Class A common stock. The following table assumes that: (i) the indicated conversion price remains the same from September 6, 2018 until the Notes are fully converted, (ii) no interest, Additional Amount (as defined in the Notes), Late Charges (as defined in the Notes) or any other additional amounts or charges are incurred or accrued under the Notes after September 6, 2018, (iii) no event of default under the Notes occurs, and (iv) the Investors prepay their Investor Notes in full before maturity of the Securities Purchase Agreement are outstanding.Notes. This table is provided for illustrative purposes only, as it is unlikely that these assumptions will be fully accurate at all relevant times.

Description of the Series Q Warrants

On December 8, 2016, Real Goods Solar entered intoEach Series Q warrant was immediately exercisable and will expire five years from the date of issuance. Initially, only 75% of the shares of Class A common stock issuable upon exercise of a Securities Purchase Agreement with several investors in connection with a registered public offering. PursuantSeries Q warrant may be exercised, which amount increases upon an Investor’s prepayment under such Investor’s Investor Note. Holders of Series Q warrants will be entitled to use cashless exercise if after the Securities Purchase Agreement, Real Goods Solar must use best efforts to maintain adate that is six months after the closing, at any time, there is no registration statement effective registeringcovering the issuance or resale of the shares of Real Goods Solar Class A common stock issuable upon exercise of the Series I Warrants for five years.Q warrants.

On February 1, 2017, Real Goods Solar enteredThe initial exercise price of the Series Q warrants was $1.12, and the current exercise price is $0.3223, subject to further adjustments for stock splits, stock dividends, and similar events. In addition, the exercise price will be subject to reduction in substantially the same manner as the conversion price of the Notes as described above under the heading “Description of the Notes–Reduction of the Conversion Price.” Unlike with respect to the Notes, a reduction in the exercise price will not result in any additional shares being issued upon exercise of the Series Q warrants.

A holder may not exercise any of the Series Q warrants, and we may not issue shares of Class A common stock upon exercise of any of the Series Q warrants if, after giving effect to the exercise, a holder together with its “attribution parties,” would beneficially own in excess of 4.99% or 9.99%, as elected by each Investor at closing, of the outstanding shares of our Class A common stock. At each holder’s option, the cap may be increased or decrease to any other percentage not in excess of 9.99%, except that any increase will not be effective until the 61st day after notice to us.

The holders of the Series Q warrants are entitled to receive any dividend or other distribution of our assets (or rights to acquire its assets) at any time after the issuance of the Series Q warrants, on an “as if exercised for Class A common stock” basis. The holders of the Series Q warrants are entitled to acquire options, convertible securities or rights to purchase our securities or property granted, issued or sold pro rata to the holders of our Class A common stock on an “as if exercised for Class A common stock” basis.

The Series Q warrants prohibit us from entering into transactions constituting a Securities Purchase Agreement with several investorsFundamental Transaction (as defined in the Series Q warrants) unless the successor entity assumes all of our obligations under the Series Q warrants and the other transaction documents in a written agreement approved by the Required Holders (as defined in the Series Q warrants). The definition of Fundamental Transactions includes, but is not limited to, mergers, a sale of all or substantially all of our assets, certain tender offers and other transactions that result in a change of control. Further, in connection with a registered public offering. PursuantChange of Control (as defined in the Series Q warrants), upon request of a holder of a Series Q warrant, we or the Successor Entity (as defined in the Series Q warrants), as the case may be, shall exchange a Series Q warrant for consideration equal to the Securities Purchase Agreement, Real Goods Solar must use best effortsBlack Scholes Value (as defined in the Series Q warrants) of such portion of such Series Q warrant subject to maintainexchange in the form of, at our election, either (i) rights convertible into the Corporate Event Consideration (as defined in the Series Q warrants) applicable to the change of control event, or (ii) cash. The definition of Change of Control is generally the same as the definition of Fundamental Transaction but excludes certain types of Fundamental Transactions.

Further, after the occurrence of an Event of Default (as defined in the Notes), at the request of a holder of a Series Q warrant, we or the Successor Entity (as defined in the Series Q warrants), as the case may be, shall purchase such holders Series Q warrant for cash in an amount equal to the Event of Default Black Scholes Value (as defined in the Series Q warrants.

Description of the April 2018 Placement Agent Warrants

The April 2018 Placement Agent Warrants have substantially the same terms as the Series Q warrants other than that the April 2018 Placement Agent Warrants have a cashless exercise right regardless of whether an effective registration statement effective registering, or a current prospectus being available for, the issuance or resale of the shares of Real Goods Solar Class A common stock issuable upon exercise of the Series K Warrants and the Series L Warrants, as applicable, for five years.

On February 7, 2017, Real Goods Solar entered into a Securities Purchase Agreement with several investors in connection with a registered public offering. Pursuant to the Securities Purchase Agreement, Real Goods Solar must use best efforts to maintain a registration statement effective registering the issuance or resale of the shares of Real Goods Solar Class A common stock issuable upon exercise of the Series M Warrants and the Series N Warrants, as applicable, for five years.

TransferApril 2018 Placement Agent and Registrar

The transfer agent and registrar for our Class A common stock is Computershare Trust Company.

Listing

Our Class A common stock is listed on the Nasdaq Capital Market under the symbol “RGSE.”

DESCRIPTION OF PREFERRED STOCK

Our board of directors is authorized, subject to any limitations prescribed by Colorado law, to issue at any time up to 50,000,000 shares of preferred stock. Our board of directors may provide for the issuance of the preferred stock in one or more series or classes with designations, preferences, limitations and relative rights determined by the board of directors without any vote or action by our shareholders as expressed in articles of amendment filed with the Colorado Secretary of State. As a result, the board has the power to issue preferred stock with voting, conversion and other rights and preferences that could adversely affect the voting power or other rights of the holders of our common stock. Although we have no current plans to issue any preferred stock, the issuance of preferred stock or of rights to purchase preferred stock could have the effect of making it more difficult for a third party to acquire us, or of discouraging a third party from attempting to acquire us. Such an issuance could also dilute the voting power or other incidents of ownership of holders of our common stock.

The issuance of preferred stock could adversely affect the voting power of holders of our common stock, and the likelihood that preferred holders will receive dividend and liquidation preferences may have the effect of delaying, deferring or preventing a change in control of the Company, which could depress the market price of our common stock.Warrants.

Unless otherwise indicatedAdditional Terms of the Purchase Agreement

Under the terms of the Purchase Agreement, we were obligated to reimburse the lead Investor for costs and expenses incurred in connection with the transaction.

So long as any Notes remain outstanding, we are prohibited from effecting or entering into an agreement to effect any Subsequent Placement involving a Variable Rate Transaction. A “Variable Rate Transaction” generally means a transaction in which we or any subsidiary issues or sells (i)(A) any securities with a conversion, exercise or exchange rate or price that is based upon and/or varies with the trading prices of the Class A common stock at any time after the initial issuance, or (B) a conversion, exercise or exchange price that is subject to reset in the prospectus supplement, all shares of preferred stockfuture, other than pursuant to be issued from time to time under this prospectus will be fully paidcertain anti-dilution provisions, or (ii) enters into any agreement whereby we or any subsidiary may sell securities at a future determined price (other than standard and nonassessable.customary “preemptive” or “participation” rights).

The Purchase Agreement also provides that, until the first anniversary of the closing of the April 2018 Offering, the Investors have the right to participate in any future Subsequent Placement (other than with respect to Excluded Securities) in an amount equal to up to 35% of such Subsequent Placement. We may not affect a Subsequent Placement during this time without complying with the terms of the participation right set forth in the Purchase Agreement.

Until the Applicable Date and at any time thereafter while any registration statement filed under the Registration Rights Agreement is not effective or the prospectus supplementcontained therein is not available for use, or any Current Public Information Failure (as defined in the Registration Rights Agreement) exists, we may not file any registration statement relating to securities that are not Registrable Securities (as defined in the preferred stock offered will containRegistration Rights Agreement), subject to some exclusions.

We were required to hold a descriptionshareholders’ meeting not later than June 30, 2018 to seek approval of the specific termsissuance of that seriesshares of Class A common stock upon conversion of the Notes and exercise of the Series Q warrants at conversion and exercise prices below the initial conversion price of the Notes and the initial exercise price of the Series Q warrants, as fixed byrequired under Nasdaq Rule 5635(d). We obtained such shareholder approval at our board of directors, including, as applicable:annual shareholders’ meeting on June 21, 2018. We were obligated to reimburse the lead investor’s legal counsel for its reasonable fees in connection with reviewing the proxy statements relating to such shareholders’ meetings in an amount not to exceed $10,000.

DESCRIPTION OF WARRANTSMay 4, 2018.

We may issue warrants forIn addition, under certain circumstances, we are required to file one or more additional registration statements if the purchasenumber of common stock, preferred stock, debt securities or other securities offered hereby orshares available under another registration statement. Warrants may be issued independently or together with common stock, preferred stock, debt securities or other securities offered hereby or under anotherany prior registration statement and may be attachedis insufficient to or separate from any such offered securities. Seriescover all of warrants may be issued under a separate warrant agreement entered into between us and a bank or trust company, as warrant agent, all as will be set forth in the prospectus supplement relating to the particular issue of warrants. The warrant agent would act solely as our agent in connection with the warrants and would not assume any obligation or relationship of agency or trust for or with any holders of warrants or beneficial owners of warrants.

As of July 10 , 2017, we had outstanding warrants to purchase 6,527,958 shares of our Class A common stock.

The prospectus supplement relating to the warrants offered will contain a description of the specific terms of that series as fixed by our board of directors, including, as applicable:

You should refer to the provisions of the warrant agreement that will be filed with the SEC in connection with the offering of warrants for the complete terms of the warrant agreement.

Prior to the exercise of any warrants, holders of such warrants will not have any rights of holders of the securities purchasable upon such exercise, including the right to receive payments of dividends, or the right to vote such underlying securities.

DESCRIPTION OF RIGHTS

Registration Rights Agreement. We may issue rights to purchase common stock, preferred stock or debt securities. These rights may be issued independently or together with any other security offered hereby and may or may not be transferable by the stockholder receiving the rights in such offering. In connection with any offering of such rights, we may enter into a standby arrangement with one or more underwriters or other purchasers pursuant to which the underwriters or other purchasers may be required to purchase any securities remaining unsubscribed for after such offering.

Each series of rights will be issued under a separate rights agreement which we will enter into with a bank or trust company, as rights agent, all as set forth in the applicable prospectus supplement. The rights agent will act solely as our agent in connection with the certificates relating to the rights and will not assume any obligation or relationship of agency or trust with any holders of rights certificates or beneficial owners of rights. We will file the rights agreement and the rights certificates relating to each series of rights with the SEC, and incorporate them by reference as an exhibit toare filing the registration statement of which this prospectus is a part on or beforeto satisfy our obligation under the time we issue a series of rights.Registration Rights Agreement.

The applicable prospectus supplement will describe the specific terms of any offering of rights for which this prospectus is being delivered, including the following:

The description in the applicable prospectus supplement of any rights that we may offer will not necessarily be complete and will be qualified in its entirety by reference to the applicable rights certificate, which will be filed with the SEC.

DESCRIPTION OF DEBT SECURITIES

We may issue senior debt securities or subordinated debt securities. Senior debt securities will be issued under an indenture, the “senior indenture,” between us and the trustee named in the applicable prospectus supplement, as trustee. Subordinated debt securities will be issued under a separate indenture, the “subordinated indenture,” between us and the trustee named in the applicable prospectus supplement, as trustee. The senior indenture and the subordinated indenture are sometimes collectively referred to in this prospectus as the “indentures.” The indentures will be subject to and governed by the Trust Indenture Act of 1939. A copy of the form of each of these indentures is filed as an exhibit to the registration statement of which this prospectus is a part. This prospectus describes the general terms and provisions of the debt securities. When we offer to sell a particular series of debt securities, we will describe the specific terms of the securities in a supplement to this prospectus. The prospectus supplement will also indicate whether the general terms and provisions described in this prospectus apply to a particular series of debt securities.

The following briefly describes the general terms and provisions of the debt securities and the indentures governing them which may be offered. The particular terms of the debt securities offered, and the extent, if any, to which these general provisions may apply to the debt securities so offered, will be described in a prospectus supplement relating to those securities. The following descriptions of the indentures are not complete and are subject to, and are qualified in their entirety by reference to, all the provisions of the respective indentures.

General

The indentures permit us to issue the debt securities from time to time, without limitation as to aggregate principal amount, and in one or more series. The indentures also do not limit or otherwise restrict the amount of other indebtedness which we may incur or other securities which we or our subsidiaries may issue, including indebtedness which may rank senior to the debt securities. Nothing in the subordinated indenture prohibits the issuance of securities representing subordinated indebtedness that is senior or junior to the subordinated debt securities. Debt securities we issue may be secured or unsecured.

Unless we give you different information in the prospectus supplement, the senior debt securities will be unsubordinated obligations and will rank equally with all of our other unsecured and unsubordinated indebtedness. Payments on the subordinated debt securities will be subordinated to the prior payment in full of all of our senior indebtedness, as described under “Subordination” and in the applicable prospectus supplement. Payments on secured debt securities will be secured by the collateral described in the applicable prospectus supplement.

We may issue debt securities if the conditions contained in the applicable indenture are satisfied. These conditions include the adoption of resolutions by our board of directors that establish the terms of the debt securities being issued. Any resolution approving the issuance of any issue of debt securities will include the terms of that issue of debt securities, which may include:

The debt securities may be issued as “original issue discount securities”Registration Rights Agreement also provides for piggyback registration rights under certain circumstances.

We are obligated to reimburse the lead investor’s legal counsel for its fees and disbursements in connection with registration, filing or qualification under the Registration Rights Agreement in an amount not to exceed $10,000 for each such registration, filing or qualification.

USE OF PROCEEDS

We will not receive any proceeds from the sale of the shares of Class A common stock by the selling shareholders.

The current exercise price of the outstanding Series Q warrants, which bear no interest or interest at a rate which at the timeare exercisable into 1,735,317 shares of issuanceClass A common stock, is below market rates and which will be sold at a substantial discount below their principal amount.$0.3223 per share. If the maturitySeries Q warrants are fully exercised for cash, we will receive proceeds of any original issue discount security is accelerated, the amount payable to the holderapproximately $559,293 which we will use for working capital. The current exercise price of the securityoutstanding January 2018 Placement Agent Warrants, which are exercisable into 128,000 shares of Class A common stock, is $1.47 per share. If all the January 2018 Placement Agent Warrants are exercised for cash, we will be determinedreceive proceeds of approximately $188,160, which we will use for working capital. The current exercise price of the outstanding April 2018 Placement Agent Warrants, which are exercisable into 730,160 shares of Class A common stock, is $0.3223 per share. If all the April 2018 Placement Agent Warrants are exercised for cash, we will receive proceeds of approximately $235,331, which we will use for working capital. If the selling shareholders elect to exercise these warrants by means of a “cashless exercise,” we will not receive any proceeds.

The selling shareholders will pay all underwriting discounts, selling commissions and expenses incurred by them for brokerage, accounting, tax or legal services or any other expenses incurred by the applicable prospectus supplement,selling shareholders in connection with the termssale of the securityshares, if any. We will bear all other costs, fees and expenses incurred in effecting the relevant indenture, but may be an amount less than the amount payable at the maturityregistration of the principalshares covered by this prospectus, including, without limitation, all registration and filing fees, Nasdaq listing fees and fees and expenses of that original issue discount security. Special federal income taxour counsel and other considerations relating to original issue discount securities will be described in the applicable prospectus supplement.our accountants.

Please seeSELLING SHAREHOLDERS

The shares of Class A common stock being offered by the prospectus supplement or pricing supplement you have received or will receive for the terms of the specific debt securities we are offering.selling shareholders consist of:

You should be aware that special U.S. federal income tax, accountingFor additional information regarding the issuance of the Notes and the warrants described above, see “DESCRIPTION OF THE TRANSACTION” above. We are registering the shares of Class A common stock in order to permit the selling shareholders to offer the shares for resale from time to time. Except for the ownership of the Notes, the Series Q warrants and the Placement Agent Warrants or as described in the table below, the selling shareholders have not had any material relationship with us within the past three years.

The table below lists the selling shareholders and other considerations may apply toinformation regarding the debt securities.beneficial ownership (as determined under Section 13(d) of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), and the rules and regulations thereunder) of the shares of Class A common stock held by each of the selling shareholders. The prospectus supplement relating to an issuesecond column lists the number of debt securities will describe these considerations.shares of Class A common stock beneficially owned by the selling shareholders, based on their respective ownership of shares of Class A common stock, convertible notes and warrants, as of September 6, 2018, assuming conversion of the convertible notes and exercise of the warrants held by each such selling shareholder on that date but taking account of any limitations on conversion and exercise set forth therein.

RegistrationThe third column lists the shares of Class A common stock being offered by this prospectus by the selling shareholders and Transferdoes not take in account any limitations on (i) conversion of the Notes set forth therein or (ii) exercise of the Series Q warrants or the Placement Agent Warrants set forth therein.

Unless otherwise indicated in the applicable prospectus supplement, the debt securities will be issued in fully registered form. Holders may present debt securities in registered form for transfer or exchange for other debt securities of the same series at the offices of the applicable indenture trustee according toIn accordance with the terms of the applicable indentureRegistration Rights Agreement, this prospectus generally covers the resale of up to 53,789,219 shares of Class A common stock issuable upon conversion and exercise of, and from time-to-time issuable under the terms of, the Notes and our Series Q warrants to purchase Class A common stock. Pursuant to agreements entered into with some of the selling shareholders, we are required to register for resale with the SEC 135% of the aggregate estimated number of shares of Class A common stock issuable upon conversion and exercise of, and from time-to-time issuable under the term of, the Notes and our Series Q warrants to purchase Class A common stock (calculated using the Alternate Conversion Price (as defined in the Notes)). We previously registered 51,038,634 shares of Class A common stock issuable under the terms of the Notes and the debt securities.Series Q warrants. As of September 6, 2018, the applicable selling shareholders have not yet exhausted the pool of shares available under the prior registration statement. As a result, the third column consist of the additional shares of Class A common stock we estimate may be issuable under the terms of the Notes and the Series Q warrants that were not registered under the prior registration statement, based on 135% of (i) the maximum number of shares of Class A common stock estimated to be issuable under the Notes determined as if the outstanding Notes were converted in full (without regard to any limitations on conversion or exercise contained therein solely for the purpose of such calculation) at the Alternate Conversion Price (as defined in the Notes), and (ii) the maximum number of shares of common stock issuable upon exercise of the Series Q warrants, calculated as of the trading day immediately preceding the date this registration statement was initially filed with the SEC. Because the conversion price of the Notes may be adjusted, the number of shares that will actually be issued may be more or less than the number of shares being offered by this prospectus.

Unless otherwise indicated inThe fourth and fifth columns assume the applicablesale of all of the shares offered by the selling shareholders pursuant to this prospectus supplement,and the debt securities will be issued in fullyprior registration statement that registered form,51,038,634 shares of Class A common stock issuable under the terms of the Notes and in denominations of $1,000 and any integral multiple thereof.the Series Q warrants.

No service charge will be required for any transfer or exchangeUnder the terms of the debt securities but weNotes, the Series Q warrants and the Placement Agent Warrants, a selling shareholder may require payment of a sum sufficient to cover any taxnot convert the Notes or other governmental charge payable in connection with any transferexercise the Series Q warrants or exchange.

Payment and Place of Payment

We will pay or deliver principal and any premium and interest in the manner, at the places and subjectPlacement Agent Warrants to the restrictions set forth in the applicable indenture, the debt securities and the applicable prospectus supplement.

Global Securities

Each indenture provides that we may issue debt securities in global form. If any series of debt securities is issued in global form, the prospectus supplement will describe any circumstances under which beneficial owners of interests in any of those global debt securities may exchange their interests for debt securities of that series and of like tenor and principal amount in any authorized form and denomination.

Events of Default

Unless otherwise indicated in the applicable prospectus supplement, the following are events of default under the senior indenture with respectextent (but only to the senior debt securities and under the subordinated indenture with respect to the subordinated debt securities:

If an eventThe number of default (other than an event of default arising from specified events in bankruptcy of us or any of our significant subsidiaries) occurs and is continuing for any series of debt securities, the indenture trustee or the holders of not less than 25% in aggregate principal amount or, under certain circumstances, issue price of the outstanding debt securities of that series may declare all amounts, or any lesser amount provided forshares in the debt securitiessecond, fourth and fifth columns reflects these limitations. The selling shareholders may sell all, some or none of that series, to be immediately due and payable.their shares in this offering. See “Plan of Distribution.”

At any time after the applicable indenture trustee or the holders have accelerated a series of debt securities, but before the applicable indenture trustee has obtained a judgment or decree for payment of money due, the holders of a majority in aggregate principal amount of outstanding debt securities of that series may rescind and annul that acceleration and its consequences, provided that all payments or deliveries due, other

* Denotes less than those due as a result of acceleration, have been made and all events of default have been remedied or waived.1%.

(1)       Ayrton Capital LLC, the investment manager to Alto Opportunity Master Fund, SPC – Segregated Master Portfolio B, has discretionary authority to vote and dispose of the shares held by Alto Opportunity Master Fund, SPC – Segregated Master Portfolio B. Waqas Khatri is the managing member of Ayrton Capital LLC and in his capacity as director of Alto Opportunity Master Fund, SPC – Segregated Master Portfolio B, may also be deemed to have investment discretion and voting power over the shares held by Alto Opportunity Master Fund, SPC – Segregated Master Portfolio B. Mr. Khatri disclaims any beneficial ownership of these shares. The holdersaddress of Ayrton Capital, LLC is 222 Broadway,19^th Floor, New York, NY 10038. One or more entities affiliated with Alto Opportunity Master Fund, SPC – Segregated Master Portfolio B have participated in prior offerings of our securities.

(2)       Consists of shares of our Class A common stock issuable (i) under the Notes (subject to a majority in principal amount or aggregate issue4.99% beneficial ownership limitation; calculated using the current conversion price of the$.03067), and (ii) upon exercise of warrants that are currently exercisable (subject to a 4.99% beneficial ownership limitation), which together represent 4.99% of our outstanding debt securitiesshares of any series may waive any default with respect to that series, except a default:

The holders of a majority in principal amount or, under certain circumstances, issue price ofpreceding sentence) because the outstanding debt securities of a series may direct the time, method and place of conducting any proceeding for any remedy available to the applicable indenture trustee or exercising any trust or power conferred on the indenture trustee with respect to debt securities of that series, provided that any direction isselling shareholder does not in conflict with any rule of law or the applicable indenture and the trustee may take other actions, other than those that might lead to personal liability, not inconsistent with the direction. Subject to the provisions of the applicable indenture relating to the duties of the indenture trustee, before proceeding to exercise any right or power under the indenture at the direction of the holders, the indenture trustee is entitled to receive from those holders reasonable security or indemnity against the costs, expenses and liabilities which it might incur in complying with any direction.

A holder of any debt security of any series will have the right to institute a proceedingreceive such shares if the selling shareholder, together with respect to the applicable indenture or for any remedy under the indenture, if:

However, the holder of any debt security or coupon has the right to receive payment of the principal of (and premium or make-whole amount, if any) and interest on, and any additional amounts in respect of, such debt security or payment of such coupon on the respective due dates (or, in the case of redemption, on the redemption date) and to institute suit for the enforcement of any such payment.our Class A common stock.

We are required to furnish to(3)       Hudson Bay Capital Management, LP, the indenture trustees annually a statement as toinvestment manager of Hudson Bay Master Fund Ltd., has voting and investment power over these securities. Sander Gerber is the performancemanaging member of Hudson Bay Capital GP LLC, which is the general partner of Hudson Bay Capital Management, LP. Each of Hudson Bay Master Fund Ltd. and Sander Gerber disclaims beneficial ownership over these securities. The address of Hudson Bay Master Fund Ltd. is c/o Hudson Bay Capital Management LP, 777 Third Avenue, 30th Floor, New York, NY 10017. Hudson Bay Master Fund Ltd. has participated in prior offerings of our obligations under the indenturessecurities and as to any default in that performance.is currently a beneficial owner of more than 5% of our Class A common stock.

Modification and Waiver

Unless otherwise indicated(4)       Consists of shares of our Class A common stock issuable (i) under our senior secured convertible notes due on April 1, 2016 (the “2016 Notes”) (subject to a 9.99% beneficial ownership limitation; calculated using a “Conversion Price” (as defined in the applicable prospectus supplement, we and2016 Notes) of $0.2785, the applicable indenture trustee may amend and modify each indenture or debt securitieslowest conversion price resulting from the defined term “Conversion Price” as of September 6, 2018), (ii) under that indenture with the consent of holders of at leastNotes (subject to a majority in principal amount or, under certain circumstances, issue9.99% beneficial ownership limitation; calculated using the current conversion price of each series$0.3067), and (iii) upon exercise of allwarrants that are currently exercisable (subject to either a 4.99% or 9.99% beneficial ownership limitation), which together represent 9.99% of our outstanding debt securities then outstandingshares of Class A common stock as of September 6, 2018. Does not include an estimated 10,698,938 additional shares of Class A common stock issuable under the indenture affected. However, without2016 Notes, the consentNotes and upon exercise of each holder of any debt security issued underwarrants (calculated in the applicable indenture, we maymanner described in the preceding sentence) because the selling shareholder does not amend or modify that indenture to:

The holders of at least a majority in principal amountsome warrants, 4.99%) of the outstanding debt securitiesshares of any series issued under that indenture may, with respect to that series, waive past defaultsour Class A common stock.

(5)       Consists of shares of our Class A common stock issuable (i) under the indenture, except2016 Notes (subject to a 9.99% beneficial ownership limitation; calculated using a “Conversion Price” (as defined in the 2016 Notes) of $0.2785, the lowest conversion price resulting from the defined term “Conversion Price” as described under “Events of Default.”September 6, 2018), and (ii) upon exercise of warrants that are currently exercisable (9.99% beneficial ownership limitation).

Unless otherwise indicated(6)       Richard Rappaport, in his capacity as Chief Executive Officer of WestPark has voting and investment power over the securities held by WestPark. Mr. Rappaport disclaims beneficial ownership of the shares of Class A common stock not owned by him. The address of WestPark is 1900 Avenue of the Stars, 3^rd Floor, Los Angeles, CA 90067. WestPark acted as our placement agent in the applicable prospectus supplement, weJanuary 2018 Offering and the applicable indenture trustee may also amendApril 2018 Offering and modify each indenture withouthas acted as our placement agent in prior securities offerings.

(7)       Consists of (i) 53,100 shares of our Class A common stock issuable under the consentJanuary 2018 Placement Agent Warrants, (ii) 317,322 shares of any holder for anyour Class A common stock issuable under the April 2018 Placement Agent Warrants and (iii) 20 shares of our Class A common stock issuable under other warrants that are currently exercisable.

(8)       Mr. Blum is an employee of WestPark. His address is WestPark Capital, Inc., 1900 Avenue of the following purposes:Stars, 3^rd Floor, Los Angeles, CA 90067.

are currently exercisable.

Consolidation, Merger and Sale of Assets

Unless otherwise indicated in the applicable prospectus supplement, we may consolidate or merge with or into any other corporation, and we may sell, lease or convey all or substantially all of our assets to any corporation, provided that the resulting corporation, if other than our company, is a corporation organized and existing under the laws of the United States or any U.S. state and assumes all of our obligations to pay or deliver the principal and any premium or make-whole amount, if any, and any interest on, the debt securities; and perform and observe all of our other obligations under the indentures and supplemental indentures. We are not, or any successor corporation, as the case may be, is not, immediately after any consolidation or merger, in default under the indentures.Class A common stock.

The indentures do not provide for any right of acceleration in the event of a consolidation, merger, sale ofselling shareholders may sell all or substantially alla portion of the assets, recapitalizationshares of Class A common stock held by them and offered hereby from time to time directly or changethrough one or more underwriters, broker-dealers or agents. If the shares of Class A common stock are sold through underwriters or broker-dealers, the selling shareholders will be responsible for underwriting discounts or commissions or agent’s commissions. The shares of Class A common stock may be sold in ourone or more transactions at fixed prices, at prevailing market prices at the time of the sale, at varying prices determined at the time of sale or at negotiated prices. These sales may be effected in transactions, which may involve crosses or block transactions, pursuant to one or more of the following methods:

The selling shareholders may also sell shares of Class A common stock ownership.under Rule 144, if available, rather than under this prospectus. In addition, the indentures doselling shareholders may transfer the shares of Class A common stock by other means not contain any provision that would protect the holders of debt securities against a sudden and dramatic declinedescribed in credit quality resulting from takeovers, recapitalizations or similar restructurings.

Regarding the Indenture Trustee

The occurrence of any default under either the senior indenture or the subordinated indenture could create a conflicting interest for the indenture trustee under the Trust Indenture Act if the same entity serves as trustee under both indentures. If that default has not been cured or waived within 90 days after the indenture trustee has or acquired a conflicting interest, the indenture trustee would generally be required by the Trust Indenture Act to eliminate that conflicting interest or resign as indenture trustee with respect to the debt securities issued under the senior indenture or the subordinated indenture.this prospectus. If the indenture trustee resigns, we are requiredselling shareholders effect such transactions by selling shares of Class A common stock to promptly appoint a successor trustee with respect toor through underwriters, broker-dealers or agents, such underwriters, broker-dealers or agents may receive commissions in the affected securities.

The Trust Indenture Act also imposes certain limitations onform of discounts, concessions or commissions from the rightselling shareholders or commissions from purchasers of the indenture trustee,shares of Class A common stock for whom they may act as a creditor of ours, to obtain payment of claims in certain cases,agent or to realize on certain property receivedwhom they may sell as principal (which discounts, concessions or commissions as to particular underwriters, broker-dealers or agents may be in respect to any cash claim or otherwise. The indenture trustee will be permitted to engage in other transactions with us, provided that, if it acquires a conflicting interest within the meaningexcess of Section 310 of the Trust Indenture Act, it generally must either eliminate that conflict or resign.

International Offering

If specifiedthose customary in the applicable prospectus supplement, we may issue debt securities outside the United States. Those debt securities will be described in the applicable prospectus supplement.types of transactions involved). In connection with any offering outsidesales of the United States, we will designate paying agents, registrarsshares of Class A common stock or other agentsotherwise, the selling shareholders may enter into hedging transactions with respect tobroker-dealers, which may in turn engage in short sales of the debt securities, as specifiedshares of Class A common stock in the applicablecourse of hedging in positions they assume. The selling shareholders may also sell shares of Class A common stock short and deliver shares of Class A common stock covered by this prospectus supplement.

We will describeto close out short positions and to return borrowed shares in the applicable prospectus supplement whether our debt securities issued outside the United States: (1)connection with such short sales. The selling shareholders may be subjectalso loan or pledge shares of Class A common stock to certain selling restrictions; (2)broker-dealers that in turn may be listed on one or more foreign stock exchanges; and (3) may have special U.S. tax and other considerations applicable to an offering outside the United States.sell such shares.

DefeasanceThe selling shareholders may pledge or grant a security interest in some or all of the Notes, Series Q warrants, Placement Agent Warrants or shares of Class A common stock owned by them and, if they default in the performance of their secured obligations, the pledgees or secured parties may offer and sell the shares of Class A common stock from time to time pursuant to this prospectus or any amendment to this prospectus under Rule 424(b)(3) or other applicable provision of the Securities Act amending, if necessary, the list of selling shareholders to include the pledgee, transferee or other successors in interest as selling shareholders under this prospectus. The selling shareholders also may transfer and donate the shares of Class A common stock in other circumstances in which case the transferees, donees, pledgees or other successors in interest will be the selling beneficial owners for purposes of this prospectus.

WeTo the extent required by the Securities Act and the rules and regulations thereunder, the selling shareholders and any broker-dealer participating in the distribution of the shares of Class A common stock may terminatebe deemed to be “underwriters” within the meaning of the Securities Act, and any commission paid, or “defease” our obligationsany discounts or concessions allowed to, any such broker-dealer may be deemed to be underwriting commissions or discounts under the indenture with respect toSecurities Act. At the debt securities of any series by taking the following steps:

Further, the defeasance cannot cause an event of default under the indenture or any other agreement or instrument and no default under the indenture or any such other agreement or instrument can exist at the time the defeasance occurs.

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Subordination

The subordinated debt securities will be subordinated in right of payment to all senior debt. In certain circumstances relating to our liquidation, dissolution, receivership, reorganization, insolvency or similar proceedings, the holders of all senior debt will first be entitled to receive payment in full before the holders of the subordinated debt securities will be entitled to receive any payment on the subordinated debt securities.

If the maturity of any subordinated debt securities is accelerated, we will have to repay all senior debt before we can make any payment on the subordinated debt securities.

Unless otherwise specified in the prospectus supplement relating to the particular series of subordinated debt securities, “senior debt” is defined as:

the principal, premium, if any, unpaid interest (including interest accruing on or after the filing of any petition in bankruptcy or for reorganization relating to us whether or not a claim for post-filing interest is allowed in such proceeding), fees, charges, expenses, reimbursement and indemnification obligations, and all other amounts payable under or in respect of the following indebtedness of us for money borrowed, whether any such indebtedness exists as of the date of the indenture or is created, incurred, assumed or guaranteed after such date:

“Senior debt” does not include:

(i) any such indebtedness, obligation or liability referred to in clauses (1) through (4) above as to which, in the instrument creating or evidencing the same or pursuant to which the same is outstanding, it is provided that such indebtedness, obligation or liability is not superior in right of payment to the subordinated debt securities, or ranks pari passu with the subordinated debt securities, (ii) any such indebtedness, obligation or liability which is subordinated to indebtedness of us to substantially the same extent as or to a greater extent than the subordinated debt securities are subordinated, (iii) any indebtedness to one of our subsidiaries and (iv) the subordinated debt securities.

The subordinated indenture does not limit or prohibit the incurrence of additional senior indebtedness, which may include indebtedness that is senior to the subordinated debt securities, but subordinate to our other obligations. Any prospectus supplement relating to a particular series of subordinated debt securities will set forth the aggregate amount of our indebtedness senior to the subordinated debt securities as of a recent practicable date.

By reason of this subordination in favor of the holders of senior indebtedness, in the event of an insolvency, our creditors who are not holders of senior indebtedness may recover less, proportionately, than holders of senior indebtedness and may recover more, proportionately, than holders of the subordinated debt securities.

The prospectus supplement may further describe the provisions, if any, which may apply to the subordination of the subordinated debt securities of a particular series.

Restrictive Covenants

The subordinated indenture does not contain any significant restrictive covenants. The prospectus supplement relating to a series of subordinated debt securities may describe certain restrictive covenants, if any, to which we may be bound under the subordinated indenture.

DESCRIPTION OF UNITS

As specified in the applicable prospectus supplement, we may issue units consisting of one or more shares of Class A common stock or preferred stock, debt securities, warrants or any combination of such securities. In addition, the prospectus supplement relating to units will describebeing offered and the terms of the offering, including the name or names of any units we issue, including as applicable:broker-dealers or agents, any discounts, commissions and other terms constituting compensation from the selling shareholders and any discounts, commissions or concessions allowed or re-allowed or paid to broker-dealers.

EXPERTS

The consolidated financial statements of Real Goods Solar, Inc. and its subsidiaries, as of and for the yearsyear ended December 31, 2015 and December 31, 2016, , incorporated in this Prospectus by reference from the Real Goods Solar, Inc. Annual Report on Form 10-K for the year ended December 31, 20162017 have been audited by Hein & Associates LLP, an independent registered public accounting firm, as stated in their report incorporated herein by reference, and have been incorporated in reliance upon such report and upon the authority of such firm as experts in accounting and auditing.

The validityconsolidated financial statements of Real Goods Solar, Inc. and its subsidiaries, as of and for the year ended December 31, 2017, incorporated in this Prospectus by reference from the Real Goods Solar, Inc. Annual Report on Form 10-K for the year ended December 31, 2017 have been audited by Moss Adams LLP, an independent registered public accounting firm, as stated in their report (which report expresses an unqualified opinion and includes an explanatory paragraph related to going concern uncertainty) incorporated herein by reference, and have been incorporated in reliance upon such report and upon the authority of such firm as experts in accounting and auditing.

WHERE YOU CAN FIND MORE INFORMATION

This prospectus, which constitutes a part of a registration statement on Form S-3 that we have filed with the SEC, omits certain of the securities being offeredinformation set forth in the registration statement. Accordingly, you should refer to the registration statement and its exhibits for further information with respect to us and our Class A common stock. Copies of the registration statement and its exhibits are on file at the offices of the SEC. This prospectus contains statements concerning documents filed as exhibits. For the complete text of any of these documents, we refer you to the copy of the document filed as an exhibit to the registration statement.

We file annual, quarterly and current reports, proxy and information statements and other information with the SEC. You may read and copy any materials we file with the SEC at the SEC’s Public Reference Room in Washington, D.C. at 100 F Street, N.E., Washington, D.C. 20549.

You may obtain information about the operation of the Public Reference Room by calling the SEC at 1(800) SEC-0330. The SEC also maintains a website that contains information we file electronically with the SEC, which you can access over the Internet at http://www.sec.gov. We maintain a website at http://www.rgsenergy.com with information about our company. Information contained on our website or any other website is not incorporated into this prospectus willand does not constitute a part of this prospectus. Our website address referenced above is intended to be passed upon for us by Brownstein Hyatt Farber Schreck, LLP, Denver, Colorado.an inactive textual reference only and not an active hyperlink to our website.

INCORPORATION OF CERTAIN DOCUMENTS BY REFERENCE

The SEC allows us to “incorporate by reference” into this prospectus the information we file with the SEC, which means that we can disclose important information to you by referring you to other documents filed separately with the SEC. The information incorporated by reference is considered part of this prospectus, and any accompanying prospectus supplement, and information that we file with the SEC subsequent to this prospectus and any accompanying prospectus supplement and prior to the termination of the particular offering referred to in athis prospectus supplement will automatically be deemed to update and supersede this information. We incorporate by reference into this prospectus and any accompanying prospectus supplement the documents listed below (excluding any portions of such documents that have been “furnished” but not “filed” for purposes of the Exchange Act unless specifically incorporated by reference herein or therein):

We also incorporate by reference all documents we subsequently file with the SEC (other than information furnished pursuant to Item 2.02 or Item 7.01 of Form 8-K or as otherwise permitted by SEC rules) pursuant to Sections 13(a), 13(c), 14 or 15(d) of the Exchange Act after the initial filing of the registration statement of which this prospectus is a part (including prior to the effectiveness of the registration statement) and prior to the termination of the offering. Any statement in a document incorporated by reference in this prospectus will be deemed to be modified or superseded to the extent a statement contained in this prospectus or any other subsequently filed document that is incorporated by reference in this prospectus modifies or supersedes such statement. Unless specifically stated to the contrary, none of the information that we disclose under Items 2.02 or 7.01 or corresponding information furnished under Item 9.01 or related exhibits of any Current Report on Form 8-K that we may from time to time furnish to the SEC will be incorporated by reference into, or otherwise included in this, prospectus.

This prospectus is part of a registration statement on Form S-3 that we have filed with the SEC relating to the securities. As permitted by SEC rules, this prospectus does not contain all of the information included in the registration statement and the accompanying exhibits and schedules we file with the SEC. We have filed certain legal documents that control the terms of the Class A common stock offered by this prospectus as exhibits to the registration statement. We may file certain other legal documents that control the terms of the Class A common stock offered by this prospectus as exhibits to reports we file with the SEC. You may refer to the registration statement and the exhibits and schedules for more information about us and our securities. The registration statement and exhibits and schedules are also available at the SEC’s Public Reference Room or through its website.

We will provide, without charge and upon oral or written request, to each person, including any beneficial owner, to whom a copy of this prospectus has been delivered, a copy of any of the documents referred to above as being incorporated by reference into this prospectus but not delivered with it. You may obtain a copy of these filings, at no cost, by writing or calling us at Real Goods Solar, Inc., 110 16^th Street, 3^rd Floor, Denver, Colorado 80202, (303) 222-8300.

Exhibits to the filings will not be provided, however, unless those exhibits have been specifically incorporated by reference in this prospectus.

WHERE YOU CAN FIND MORE INFORMATION

We file annual, quarterly and current reports, proxy and information statements and other information with the SEC. You may read and copy any materials we file with the SEC at the SEC’s Public Reference Room in Washington, D.C. at 100 F Street, N.E., Room 1580, Washington, D.C. 20549.

You may obtain information about the operation of the Public Reference Room by calling the SEC at 1-800-SEC-0330. The SEC also maintains a website that contains information we file electronically with the SEC, which you can access over the Internet at http://www.sec.gov. We maintain a website at http://www.rgsenergy.com with information about our company. Information contained on our website or any other website is not incorporated into this prospectus and does not constitute a part of this prospectus. Our website address referenced above is intended to be an inactive textual reference only and not an active hyperlink to our website.

PART II. INFORMATION NOT REQUIRED IN PROSPECTUS

Item 14. Other Expenses of Issuance and Distribution.Distribution

The following is a statement of the estimated expenses to be incurred by the registrant in connection with the sale of the securities being registered.registered will be borne by the registrant. Other than the SEC registration fee, the amounts stated are estimates.

Item 15. Indemnification of Directors and Officers.Officers

The Colorado Business Corporation Act (the “CBCA”) generally provides that a corporation may indemnify a person made party to a proceeding because the person is or was a director against liability incurred in the proceeding if: the person’s conduct was in good faith; the person reasonably believed, in the case of conduct in an official capacity with the corporation, that such conduct was in the corporation’s best interests, and, in all other cases, that such conduct was at least not opposed to the corporation’s best interests; and, in the case of any criminal proceeding, the person had no reasonable cause to believe that the person’s conduct was unlawful. The CBCA prohibits such indemnification in a proceeding by or in the right of the corporation in which the person was adjudged liable to the corporation or in connection with any other proceeding in which the person was adjudged liable for having derived an improper personal benefit. The CBCA further provides that, unless limited by its articles of incorporation, a corporation shall indemnify a person who was wholly successful, on the merits or otherwise, in the defense of any proceeding to which the person was a party because the person is or was a director or officer of the corporation, against reasonable expenses incurred by the person in connection with the proceeding. In addition, a director or officer, who is or was a party to a proceeding, may apply for indemnification to the court conducting the proceeding or to another court of competent jurisdiction. The CBCA allows a corporation to indemnify and advance expenses to an officer, employee, fiduciary or agent of the corporation to the same extent as a director.

As permitted by the CBCA, the Company’s articles of incorporation and bylaws generally provide that the Company shall indemnify its directors and officers to the fullest extent permitted by the CBCA. In addition, the Company may also indemnify and advance expenses to an officer who is not a director to a greater extent, not inconsistent with public policy, and if provided for by its bylaws, general or specific action of the Company’s board of director or shareholders.

The Company has entered into substantively identical Indemnification Agreements with certain current and former directors and officers (the “Indemnitees”), which generally provide that, to the fullest extent permitted by Colorado law, the Company shall indemnify such Indemnitee if the Indemnitee was or is a party or is threatened to be made a party to any threatened, pending or completed action, suit or proceeding, whether civil, criminal, administrative or investigative, by reason of the fact that the Indemnitee is or was or has agreed to serve at the Company’s request as a director, officer, employee or agent of the Company, or while serving as a director or officer of the Company, is or was serving or has agreed to serve at the Company’s request as a director, officer, employee or agent of another corporation, partnership, joint venture, trust, employee benefit plan or other enterprise, or by reason of any action alleged to have been taken or omitted in such capacity or by reason of the imposition upon such officer or director of any federal and/or state income tax obligation (inclusive of any interest and penalties, if applicable), that is imposed on such officer or director with respect to income, “phantom income,” rescinded or unconsummated transactions, or any other allegedly taxable event for which no benefit was received by such officer or director. The indemnification obligation includes, without limitation, claims for monetary damages against an Indemnitee in respect of an alleged breach of fiduciary duties and generally covers expenses (including attorneys’ fees), judgments, fines and amounts paid in settlement actually and reasonably incurred by an Indemnitee or on an Indemnitee’s behalf in connection with such action, suit or proceeding and any appeal therefrom, but shall only be provided if the Indemnitee acted in good faith; and, in the case of conduct in an official capacity with the corporation, if such conduct was in the Company’s best interests, and, in all other cases, if such conduct was at least not opposed to the Company’s best interests; and, with respect to any criminal action, suit or proceeding, if the Indemnitee had no reasonable cause to believe the Indemnitee’s conduct was unlawful.

Section 7-108-402(1) of the CBCA permits a corporation to include in its articles of incorporation a provision eliminating or limiting the personal liability of directors to the corporation or its shareholders for monetary damages for any breach of fiduciary duty as a director (except for breach of a director’s duty of loyalty, acts or omissions not in good faith or which involve intentional misconduct or a knowing violation of law, unlawful distributions, or any transaction from which the director derived improper personal benefit). Further, Section 7-108-402(2) of the CBCA provides that no director or officer shall be personally liable for any injury to persons or property arising from a tort committed by an employee, unless the director or officer was either personally involved in the situation giving rise to the litigation or committed a criminal offense in connection with such situation.

As permitted by the CBCA, the Company’s articles of incorporation provide that the personal liability of the Company’s directors to the Company or its shareholders is limited to the fullest extent permitted by the CBCA. The Indemnification Agreements described above also provide that the Company’s indemnification obligation includes, without limitation, claims for monetary damages against the Indemnitee in respect of an alleged breach of fiduciary duties to the fullest extent permitted by the CBCA.

Section 7-109-108 of the CBCA provides that a corporation may purchase and maintain insurance on behalf of a person who is or was a director, officer, employee, fiduciary or agent of the corporation, or who, while a director, officer, employee, fiduciary or agent of the corporation, is or was serving at the request of the corporation as a director, officer, partner, trustee, employee, fiduciary or agent of another entity or an employee benefit plan, against liability asserted against or incurred by the person in that capacity or arising from the person’s status as a director, officer, employee, fiduciary or agent, whether or not the corporation would have power to indemnify the person against the same liability under the CBCA.

As permitted by the CBCA, the Company’s bylaws authorize the Company to purchase and maintain such insurance. The Company currently maintains a directors and officers insurance policy insuring its past, present and future directors and officers, within the limits and subject to the limitations of the policy, against expenses in connection with the defense of actions, suits or proceedings, and certain liabilities that might be imposed as a result of such actions, suits or proceedings.

Item 16. Exhibits.Exhibits

The exhibits listed in the exhibit index immediately following the signature pages are filed as part of this registration statement.

Item 17. Undertakings.Undertakings

The undersigned registrant hereby undertakes:

(1) To file, during any period in which offers or sales are being made, a post-effective amendment to this registration statement:

(i) To include any prospectus required by Section 10(a)(3) of the Securities Act;

(ii) To reflect in the prospectus any facts or events arising after the effective date of the registration statement (or the most recent post-effective amendment thereof) which, individually or in the aggregate, represent a fundamental change in the information set forth in the registration statement. Notwithstanding the foregoing, any increase or decrease in volume of securities offered (if the total dollar value of securities offered would not exceed that which was registered) and any deviation from the low or high end of the estimated maximum offering range may be reflected in the form of prospectus filed with the SEC pursuant to Rule 424(b) if, in the aggregate, the changes in volume and price represent no more than a 20 percent change in the maximum aggregate offering price set forth in the “Calculation of Registration Fee” table in the effective registration statement;

(iii) To include any material information with respect to the plan of distribution not previously disclosed in the registration statement or any material change to such information in the registration statement;

provided, however, that paragraphs (1)(i), (1)(ii) and (1)(iii) do not apply if the information required to be included in a post-effective amendment by those paragraphs is contained in reports filed with or furnished to the SEC by the Registrantregistrant pursuant to Section 13 or Section 15(d) of the Exchange Act, that are incorporated by reference in this registration statement, or is contained in a form of prospectus filed pursuant to Rule 424(b) that is part of the registration statement.

(2) That, for the purpose of determining any liability under the Securities Act, each such post-effective amendment shall be deemed to be a new registration statement relating to the securities offered therein, and the offering of such securities at that time shall be deemed to be the initial bona fide offering thereof.

(3) To remove from registration by means of a post-effective amendment any of the securities being registered which remain unsold at the termination of the offering.

(4) That, for the purpose of determining liability under the Securities Act to any purchaser, each prospectus filed pursuant to Rule 424(b) as part of a registration statement relating to an offering, other than registration statements relying on Rule 430B or other than prospectuses filed in reliance on Rule 430A, shall be deemed to be part of and included in the registration statement as of the date it is first used after effectiveness.Provided, however, that no statement made in a registration statement or prospectus that is part of the registration statement or made in a document incorporated or deemed incorporated by reference into the registration statement or prospectus that is part of the registration statement will, as to a purchaser with a time of contract of sale prior to such first use, supersede or modify any statement that was made in the registration statement or prospectus that was part of the registration statement or made in any such document immediately prior to such date of first use.

(5) That, for purposes of determining any liability under the Securities Act, each filing of the registrant’s annual report pursuant to Sectionsection 13(a) or Sectionsection 15(d) of the Exchange Act that is incorporated by reference in the registration statement shall be deemed to be a new registration statement relating to the securities offered therein, and the offering of such securities at that time shall be deemed to be the initial bona fide offering thereof.

(6) Insofar as indemnification for liabilities arising under the Securities Act may be permitted to directors, officers and controlling persons of the Registrantregistrant pursuant to the indemnification provisions described herein, or otherwise, the Registrantregistrant has been advised that in the opinion of the SEC such indemnification is against public policy as expressed in the Securities Act and is, therefore, unenforceable. In the event that a claim for indemnification against such liabilities (other than the payment by the Registrantregistrant of expenses incurred or paid by a director, officer or controlling person of the Registrantregistrant in the successful defense of any action, suit or proceeding) is asserted by such director, officer or controlling person in connection with the securities being registered, the Registrantregistrant will, unless in the opinion of its counsel the matter has been settled by controlling precedent, submit to a court of appropriate jurisdiction the question whether such indemnification by it is against public policy as expressed in the Securities Act and will be governed by the final adjudication of such issue.

The undersigned registrant hereby further undertakes that:

1           For purposes of determining any liability under the Securities Act, the information omitted from the form of prospectus filed as part of this registration statement in reliance under Rule 430A and contained in a form of prospectus filed by the registrant pursuant to Rule 424(b)(1) or (4), or 497(h) under the Securities Act shall be deemed to be part of this registration statement as of the time it was declared effective.

2.           For the purpose of determining any liability under the Securities Act, each post-effective amendment that contains a form of prospectus shall be deemed to be a new registration statement relating to the securities offered therein, and the offering of such securities at that time shall be deemed to be the initial bona fide offering thereof.

The undersigned hereby undertakes to file an application for the purpose of determining the eligibility of the trustee to act under subsection (a) of Section 310 of the Trust Indenture Act in accordance with the rules and regulations prescribed by the SEC under Section 305(b)(2) of that Act.

SIGNATURES

Pursuant to the requirements of the Securities Act of 1933, the Registrantregistrant certifies that it has reasonable grounds to believe that it meets all of the requirements for filing on Form S-3 and has duly caused this registration statement to be signed on its behalf by the undersigned, thereunto duly authorized, in the City of Denver, State of Colorado, on July 11 , 2017.September 7, 2018.

POWER OF ATTORNEY

KNOW ALL PEOPLE BY THESE PRESENTS, that each person whose signature appears below constitutes and appoints Dennis Lacey and Alan Fine, and each of them severally, as his or her true and lawful attorneys-in-fact and agents, each acting alone with full power of substitution and resubstitution, for him or her and in his or her name, place and stead, in any and all capacities, to sign any or all amendments (including pre-effective and post-effective amendments) and exhibits to this Registration Statement on Form S-3, and to any registration statement relating to the same offering of securities that are filed pursuant to Rule 462 of the Securities Act of 1933, as amended, and to file the same, with all exhibits thereto, and all other documents in connection therewith, with the SEC, granting unto said attorneys-in-fact and agents, and each of them, full power and authority to do and perform each and every act and thing requisite and necessary to be done in connection therewith, as fully to all intents and purposes as he or she might or could do in person, hereby ratifying and confirming all that said attorneys-in-fact and agents, or any of them, or theirs or his substitute or substitutes, may lawfully do or cause to be done by virtue hereof.

Pursuant to the requirements of the Securities Act of 1933, this registration statement has been signed by the following persons in the capacities and on the dates indicated.

EXHIBITS INDEX

† Filed herewith