Spruce Power Holding (SPRU) 10-Q 15 Nov 21 2021 Q3 Quarterly report Financial data

Document And Entity Information

Document And Entity Information - shares	9 Months Ended
	Sep. 30, 2021	Nov. 10, 2021
Document Information Line Items
Entity Registrant Name	XL Fleet Corp.
Trading Symbol	XL
Document Type	10-Q
Current Fiscal Year End Date	--12-31
Entity Common Stock, Shares Outstanding		139,418,820
Amendment Flag	false
Entity Central Index Key	0001772720
Entity Current Reporting Status	Yes
Entity Filer Category	Non-accelerated Filer
Document Period End Date	Sep. 30, 2021
Document Fiscal Year Focus	2021
Document Fiscal Period Focus	Q3
Entity Small Business	true
Entity Emerging Growth Company	true
Entity Shell Company	false
Entity Ex Transition Period	false
Document Quarterly Report	true
Document Transition Report	false
Entity File Number	001-38971
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	83-4109918
Entity Address, Address Line One	145 Newton Street
Entity Address, City or Town	Boston
Entity Address, State or Province	MA
Entity Address, Postal Zip Code	02135
City Area Code	(617)
Local Phone Number	718-0329
Title of 12(b) Security	Shares of common stock, $0.0001 par value
Security Exchange Name	NYSE
Entity Interactive Data Current	Yes

Unaudited Condensed Consolidate

Unaudited Condensed Consolidated Balance Sheets - USD ($) $ in Thousands		Sep. 30, 2021	Dec. 31, 2020
Current assets:
Cash and cash equivalents		$ 366,748	$ 329,641
Restricted cash		150	150
Accounts receivable, net		2,822	10,559
Inventory, net		18,104	3,574
Prepaid expenses and other current assets		1,210	1,396
Total current assets		389,034	345,320
Property and equipment, net		3,201	579
Intangible assets, net		1,773	593
Right-of-use asset		4,471
Investment in convertible note		3,000
Goodwill		8,841	489
Other assets		80	32
Total assets		410,400	347,013
Liabilities and stockholders’ equity
Current portion of long-term debt		86	110
Accounts payable		3,197	4,372
Lease liability, current		880
Accrued expenses and other current liabilities		12,954	4,601
Total current liabilities		17,117	9,083
Long-term debt, net of current portion		37	98
Deferred revenue		706	305
Lease liability, non-current		3,526
Warrant liabilities		13,582	143,295
Contingent consideration		1,006	924
New market tax credit obligation	[1]	4,372	4,412
Total liabilities		40,346	158,117
Commitments and contingencies (Note 13)
Stockholders’ equity
Common stock, $0.0001 par value; 350,000,000 shares authorized at September 30, 2021 and December 31, 2020; 139,403,914 and 131,365,254 issued and outstanding at September 30, 2021 and December 31, 2020, respectively		14	13
Additional paid-in capital		454,327	317,084
Accumulated deficit		(84,287)	(128,201)
Total stockholders’ equity		370,054	188,896
Total liabilities and stockholders’ equity		$ 410,400	$ 347,013
[1]	Held by variable interest entity

Unaudited Condensed Consolida_2

Unaudited Condensed Consolidated Balance Sheets (Parentheticals) - $ / shares	Sep. 30, 2021	Dec. 31, 2020
Statement of Financial Position [Abstract]
Common stock, par value (in Dollars per share)	$ 0.0001	$ 0.0001
Common stock, shares authorized	350,000,000	350,000,000
Common stock, shares issued	139,403,914	131,365,254
Common stock, shares outstanding	139,403,914	131,365,254

Unaudited Condensed Consolida_3

Unaudited Condensed Consolidated Statements of Operations - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Income Statement [Abstract]
Revenues	$ 3,200	$ 6,328	$ 7,569	$ 9,472
Cost of revenues	2,510	5,561	6,633	8,713
Gross profit	690	767	936	759
Operating expenses:
Research and development	3,217	1,646	7,438	3,297
Selling, general, and administrative expenses	12,742	5,304	31,522	10,798
Loss from operations	(15,269)	(6,183)	(38,024)	(13,336)
Other (income) expense:
Interest expense, net	14	1,266	35	4,291
Loss on extinguishment of debt				1,038
Loss on asset disposal	24		45
Change in fair value of obligation to issue shares of common stock to sellers of World Energy	(532)		(18)
Change in fair value of warrant liability	(7,229)		(81,960)
Change in fair value of convertible notes payable derivative liability		(5,172)		3,565
Other income	(15)		(40)
Net (loss) income	$ (7,531)	$ (2,277)	$ 43,914	$ (22,230)
Net (loss) income per share, basic (in Dollars per share)	$ (0.05)	$ (0.03)	$ 0.32	$ (0.27)
Net (loss) income per share, diluted (in Dollars per share)	$ (0.05)	$ (0.03)	$ 0.3	$ (0.27)
Weighted-average shares outstanding, basic (in Shares)	139,392,170	83,299,127	138,082,355	82,820,099
Weighted-average shares outstanding, diluted (in Shares)	139,392,170	83,299,127	148,469,108	82,820,099

Unaudited Condensed Consolida_4

Unaudited Condensed Consolidated Statements of Changes in Stockholders' Equity (Deficit) - USD ($) $ in Thousands	Common Stock	Additional Paid-In Capital	Accumulated Deficit	Total
Balance at Dec. 31, 2019	$ 8	$ 53,887	$ (67,595)	$ (13,700)
Balance (in Shares) at Dec. 31, 2019	80,400,727
Exercise of warrants		34		34
Exercise of warrants (in Shares)	2,584,637
Exercise of stock options
Exercise of stock options (in Shares)	5,300
Stock-based compensation expense		52		52
Net income (loss)			(6,454)	(6,454)
Balance at Mar. 31, 2020	$ 8	53,973	(74,049)	(20,068)
Balance (in Shares) at Mar. 31, 2020	82,990,664
Stock-based compensation expense		225		225
Net income (loss)			(13,499)	(13,499)
Balance at Jun. 30, 2020	$ 8	54,198	(87,548)	(33,342)
Balance (in Shares) at Jun. 30, 2020	82,990,664
Exercise of warrants		850		850
Exercise of warrants (in Shares)	1,064,524
Exercise of stock options		21		21
Exercise of stock options (in Shares)	85,705
Stock-based compensation expense		386		386
Net income (loss)			(2,277)	(2,277)
Balance at Sep. 30, 2020	$ 8	55,455	(89,825)	(34,362)
Balance (in Shares) at Sep. 30, 2020	84,140,893
Balance at Dec. 31, 2020	$ 13	317,084	(128,201)	188,896
Balance (in Shares) at Dec. 31, 2020	131,365,254
Exercise of warrants
Exercise of warrants (in Shares)	233,555
Exercise of Public warrants	$ 1	85,554		85,555
Exercise of Public warrants (in Shares)	7,441,020
Settlement of warrant liability upon exercise of warrants		47,162		47,162
Settlement of warrant liability upon call of warrants		591		591
Proceeds from PIC shares recapitalization		75		75
Exercise of stock options		16		16
Exercise of stock options (in Shares)	65,875
Stock-based compensation expense		442		442
Net income (loss)			61,914	61,914
Balance at Mar. 31, 2021	$ 14	450,924	(66,287)	384,651
Balance (in Shares) at Mar. 31, 2021	139,105,704
Exercise of stock options		7		7
Exercise of stock options (in Shares)	29,870
Issuance of shares in business combination with World Energy		1,439		1,439
Issuance of shares in business combination with World Energy (in Shares)	231,002
Stock-based compensation expense		754		754
Net income (loss)			(10,469)	(10,469)
Balance at Jun. 30, 2021	$ 14	453,124	(76,756)	376,382
Balance (in Shares) at Jun. 30, 2021	139,366,576
Exercise of stock options		9		9
Exercise of stock options (in Shares)	37,338
Stock-based compensation expense		1,194		1,194
Net income (loss)			(7,531)	(7,531)
Balance at Sep. 30, 2021	$ 14	$ 454,327	$ (84,287)	$ 370,054
Balance (in Shares) at Sep. 30, 2021	139,403,914

Unaudited Condensed Consolida_5

Unaudited Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020
Operating activities:
Net income (loss)	$ 43,914	$ (22,230)
Adjustments to reconcile net income (loss) to net cash used in operating activities:
Stock-based compensation	2,390	663
Bad debt expense	204
Depreciation and amortization expense	1,074	474
Contingent consideration	(23)	679
Change in fair value of obligation to issue shares of common stock to sellers of World Energy	(18)
Fair value change of derivative liability	(81,960)	3,565
Loss on extinguishment of debt		1,038
Loss on disposal of assets	45
Change in operating right-of-use assets	7
Interest on finance leases	25
Debt discount	(40)	3,143
Changes in operating assets and liabilities:
Accounts receivable, net	10,883	(5,240)
Inventory, net	(13,248)	(2,313)
Prepaid expenses and other current assets	286	1
Other assets	(23)	(152)
Accounts payable	(2,269)	3,416
Accrued expenses and other current liabilities	4,420	3,869
Deferred revenue	118
Net cash used in operating activities	(34,215)	(13,087)
Investing activities:
Payments to acquire net assets of World Energy, net of cash acquired	(8,188)
Purchase of convertible note	(3,000)
Purchases of property and equipment	(2,917)	(162)
Net cash used in investing activities	(14,105)	(162)
Financing activities:
Proceeds from the issuance of subordinated convertible promissory notes		8,100
Proceeds from paycheck protection program		1,100
Repayments of revolving line of credit		(646)
Repayments of debt	(85)	(513)
Repayments under financing leases	(150)
Proceeds from revolving line of credit		2,500
Proceeds from the exercise of warrants		884
Proceeds from recapitalization of PIC shares	75
Proceeds from exercise of stock options	32	21
Proceeds from exercise of Public Warrants	85,555
Net cash provided by financing activities	85,427	11,446
Net increase in cash and cash equivalents and restricted cash:	37,107	(1,803)
Cash, cash equivalents, and restricted cash at beginning of period	329,791	3,536
Cash, cash equivalents, and restricted cash at end of period	366,898	1,733
Supplemental disclosure of cash flow information:
Cash paid for interest	35	156
Supplemental disclosures of noncash investing and financing information:
Settlement of warrant liability upon exercise of Public Warrants	47,162
Settlement of warrant liability upon call of warrants	591
Reduce derivative liability for extinguishment of convertible notes payable		(1,349)
Increase derivative liability for issuance of convertible notes payable		5,638
Equipment financing	$ 271

Organization and Description of

Organization and Description of Business	9 Months Ended
	Sep. 30, 2021
Organization, Description of Business and Liquidity [Abstract]
Organization and Description of Business	Note 1. Organization and Description of Business Description of Business: Merger and Reorganization: Acquisition of World Energy: Purchase of eNow Convertible Note COVID-19 Worldwide Pandemic: Consistent with the actions taken by governmental authorities, the Company has taken appropriately cautious steps to protect its workforce and support community efforts. As part of these efforts, and in accordance with applicable government directives, beginning in late March 2020, the Company implemented work from home policies where practical at its facilities. Effective September 30, 2021, all 150 employees were working full-time from one of the Company’s five offices or from home. Current COVID-19 policies include universal facial covering requirements if not vaccinated, rearranging facilities to follow social distancing protocols, employees self-screening before going into the office, enhanced cleaning procedures, ability to go mask-free if proof of vaccination is provided to Human Resources, and strict quarantine protocols for any suspected or confirmed employee cases. However, the COVID-19 pandemic and the continued precautionary actions taken related to COVID-19 have adversely impacted, and are expected to continue to adversely impact, its operations, its contractors and the automotive original equipment manufacturers. The Company has experienced, and expects to continue to experience, reduced operations and production line shutdowns at vehicle OEMs due to COVID-19, limitations on travel by the Company’s personnel and personnel of the Company’s customers, and future delays or shutdowns of vehicle OEMs or the Company’s suppliers. The COVID-19 pandemic and the protocols and procedures the Company has implemented in response to the pandemic have caused some delays in operational activities. The full impact of the COVID-19 pandemic on its business and results of operations subsequent to September 30, 2021 will depend on future developments, such as the ultimate duration and scope of the outbreak and its impact on its operations and impact on its customers and industry partners.

Summary of Significant Accounti

Summary of Significant Accounting Policies	9 Months Ended
	Sep. 30, 2021
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	Note 2. Summary of Significant Accounting Policies Basis of consolidated financial statement presentation: Use of estimates: Concentration of Credit Risk: With respect to trade receivables, the Company routinely assesses the financial strength of its customers and, as a consequence, believes that the receivable credit risk exposure is limited. As of September 30, 2021, two customers accounted for approximately 48% and 21% of accounts receivable. As of December 31, 2020, one customer accounted for approximately 82% of accounts receivable. For the three months ended September 30, 2021 and 2020, two customers and two customers accounted for approximately 80% and 73% of revenues, respectively. For the nine months ended September 30, 2021 and 2020, two customers and two customers accounted for approximately 56% and 69% of revenues, respectively. Cash, cash equivalents, and restricted cash: Restricted cash held at both September 30, 2021 and December 31, 2020, consists of $150 for a bank deposit required for a letter of credit which is reserved for the Company’s California lease. The following table provides a reconciliation of cash, cash equivalents, and restricted cash in the condensed consolidated balance sheets to the total amount shown in the condensed consolidated statements of cash flows: As of September 30, 2021 2020 Cash and cash equivalents $ 366,748 $ 1,583 Restricted cash 150 150 Total cash, cash equivalents, and restricted cash $ 366,898 $ 1,733 Accounts receivable, net: Inventory, net: Fair value measurements: The fair value of the Company’s financial assets and liabilities reflects management’s estimate of amounts that the Company would have received in connection with the sale of the assets or paid in connection with the transfer of the liabilities in an orderly transaction between market participants at the measurement date. In connection with measuring the fair value of its assets and liabilities, the Company seeks to maximize the use of observable inputs (market data obtained from independent sources) and to minimize the use of unobservable inputs (internal assumptions about how market participants would price assets and liabilities). The following fair value hierarchy is used to classify assets and liabilities based on the observable inputs and unobservable inputs used in order to value the assets and liabilities: Level 1 Level 2 Level 3 An asset’s or liability’s fair value measurement level within the fair value hierarchy is based on the lowest level of any input that is significant to the fair value measurement. Valuation techniques used need to maximize the use of observable inputs and minimize the use of unobservable inputs. See Note 9 for additional information on assets and liabilities measured at fair value. The Company believes its valuation methods are appropriate and consistent with other market participants, however the use of different methodologies or assumptions to determine the fair value of certain financial instruments could result in a different fair value measurement at the reporting date. The Company’s financial instruments consist of cash and cash equivalents, restricted cash, accounts receivable, accounts payable, accrued liabilities, contingent consideration liability, long-term debt and warrant liability. The carrying value of cash and cash equivalents, accounts receivable, accounts payable, and accrued expenses approximates fair value because of the short-term nature of those instruments. Prepaid expenses and other current assets: Revenue: Revenue is recognized upon transfer of control to the customer, which occurs when the Company has a present right to payment, legal title has passed to the customer, the customer has the significant risks and rewards of ownership, and where acceptance is not a formality, the customer has accepted the product or service. For the Drive Systems products, in general, transfer of control is upon shipment of the equipment as the terms are FOB shipping point or equivalent, as the Company has no other promised goods or services in its contracts with customers. In limited instances, the Company provides installation services to end-user fleet customers related to the purchased hybrid electric powertrain equipment. When provided, these installation services are not distinct within the context of the contract due to the fact that the end-use fleet customer is purchasing a completed modification to its vehicles and therefore, the installation services involve significant integration to integrate the hybrid electric powertrain equipment with the customer’s vehicle. As a result, the hybrid electric powertrain equipment and installation services represent a single performance obligation within these contracts with customers. The Company recognizes the revenue for the equipment sale and installation service for Drive System products at the same time, which is after the installation is complete. The Company has elected to treat shipping and handling activities related to contracts with channel partner customers for Drive System products as costs to fulfill the promise to transfer the associated equipment and not as a separate performance obligation. For the XL Grid solutions, in general, transfer of control is upon the acceptance and certification of project completion by both the end customer and the utility who is funding the energy incentives, representing a single performance obligation of the Company. Due to the short-term nature of projects (typically two to three weeks), the Company recognizes revenues from all XL Grid solutions activities at a point in time, when persuasive evidence of an arrangement exists, delivery has occurred, the price is fixed or determinable and the Company has the right to payment for the transferred asset. The Company also assesses multiple contracts entered into by the same customer in close proximity to determine if the contracts should be combined for revenue recognition purposes. During the duration of a project for XL Grid solutions, all direct material and labor costs and those indirect costs related to the project are capitalized, and customer deposits are treated as liabilities. Once a project has been completed and the energy efficiency upgrades have been deemed to meet client specifications, capitalized costs are charged to earnings. For both Drive Systems and XL Grid solutions, when the Company’s contracts with customers contain multiple performance obligations, which is infrequent, the contract transaction price is allocated on a relative standalone selling price (SSP) basis to each performance obligation. The Company determines standalone selling prices based on observable selling prices for the sale of its systems. For extended warranties, the Company determines SSP based on expected cost plus margin. The Company establishes the margin based on review of market conditions and margins obtained by market participants for similar services. Any allocation of the transaction price required is determined at the contracts’ inception. The transaction price is the amount of consideration to which the Company expects to be entitled in exchange for transferring goods and services to the customer. Revenue is recorded based on the transaction price, which is solely made up of fixed consideration for its products and services. The Company does not adjust transaction price for the effects of a significant financing component when the period between the transfer of the promised good or service to the customer and payment for that good or service by the customer is expected to be one year or less. The Company has not identified any significant financing components to date. The Company’s sales can in certain instances include non-cash consideration in the form of the customer transferring to the Company, the customer’s rights to cash incentives from programs administered by municipalities related to hybrid vehicle programs that a customer is entitled to as a result of its purchase. The incentives are fixed amounts that are readily determinable. The Company values the non-cash consideration at its fair value, which generally is the amount of the incentive. Payment terms on invoices range from 30 to 60 days. The Company excludes from revenue any sales tax and other government-assessed and imposed taxes on revenue generating activities that are invoiced to customers. The Company has elected to apply the practical expedient to expense costs to obtain contracts, which principally relate to sales commissions, at the time the liability is incurred when the expected amortization period is one year or less. Warranties Customers who purchase the Drive Systems are provided limited-assurance-type warranties for equipment and work performed under the contracts. The warranty period typically extends for 3 years following transfer of control of the equipment. The warranties solely relate to correction of product defects during the warranty period, which is consistent with similar warranties by offered by competitors. Therefore, the Company has determined that these warranties are outside the scope of ASC 606 and will continue to be accounted for under ASC 460, Guarantees. Customers of XL Grid solutions are provided limited-assurance-type warranties for a term of one year for installation work performed under its contracts. Warranties for equipment sold to customers are provided by the original equipment manufacturers. For both Drive Systems and XL Grid solutions, the Company accrues the estimated cost of product warranties for unclaimed charges based on historical experiences and expected results. Should product failure rates and material usage costs differ from these estimates revisions to the estimated warranty liability would be required. The Company periodically assesses the adequacy of its recorded product warranty liabilities and adjusts the balances as required. Warranty expense is recorded as a component of cost of product revenue in the statements of operations. Share-based compensation: Stock Options The Company accounts for stock-based compensation related to these awards based on the fair value of the awards. The Company uses the Black-Scholes option pricing model to determine the fair value of stock-based awards, and recognizes the compensation cost on a straight line basis over the requisite service period of the awards for employee, which is typically the four-year vesting period of the award, and effective contract period specified in the award agreement for non-employee. The fair value of common stock is determined based on the closing price on the New York Stock Exchange at each award grant date. The determination of the fair value of share-based payment awards utilizing the Black-Scholes model is affected by the stock price and a number of assumptions, including expected volatility, expected life, risk- free interest rate and expected dividends. The Company does not have a history of trading in its common stock as it was not a public company until December 21, 2020, and as such volatility was estimated using historical volatilities of comparable public entities. The expected life of the awards is estimated based on a simplified method, which uses the average of the vesting term and the original contractual term. The risk-free interest rate assumption is based on observed interest rates appropriate for the expected life of the awards. The dividend yield assumption is based on history and expectation of paying no dividends. Forfeitures are accounted for as they occur. The fair value of stock options issued for the nine months ended September 30, 2021 and 2020 was measured with the following assumptions: For the Nine Months Ended 2021 2020 Expected volatility 78.1 – 88.2 % 80.0 – 80.1 % Expected term (in years) 6.25 6.25 Risk-free interest rate 0.4 – 1.9 % 0.1 – 0.2 % Expected dividend yield 0.0 % 0.0 % Restricted Stock Units Restricted stock units generally vest over the requisite service periods (vesting on a straight–line basis). The fair value of a stock award is equal to the fair market value of a share of the Company’s Common stock on the grant date. The Company accounts for the forfeiture of equity awards as they occur. Warrant Liabilities: Research and development expense: Net income (loss) per share: Segment Information: Related parties: Recent accounting pronouncements issued and adopted: In December 2019, the FASB issued ASU 2019-12, Income Taxes (Topic 740): Simplifying the Accounting for Income Taxes

Revenue

Revenue	9 Months Ended
	Sep. 30, 2021
Revenue [Abstract]
Revenue	Note 3. Revenue The following table represents the Company’s revenues for the three and nine months ended September 30, 2021 and 2020, respectively, disaggregated, by sales channel. Disaggregation of revenue: Three Months Ended September 30, Nine Months Ended September 30, 2021 2020 2021 2020 Revenue from the sale of Drive Systems: Revenue direct to customers $ 366 $ 959 $ 1,138 $ 2,020 Revenue through channel partners 189 5,369 1,374 7,452 Revenue from the sale of XL Grid solutions – which are sold direct to customers 2,645 - 5,057 - Total revenue $ 3,200 $ 6,328 $ 7,569 $ 9,472 Remaining performance obligations: Contract Balances: Costs to obtain a contract: Warranties: The following is a roll-forward of the Company’s accrued warranty liability: For the September 30, For the Ended December 31, 2020 2021 Balance at the beginning of the period $ 1,735 $ 1,009 Acquisition date accrual for World Energy acquisition 25 - Accrual for warranties issued 126 912 Warranty fulfillment charges (285 ) (186 ) Balance at the end of the period $ 1,601 $ 1,735 The warranty liability is included in accrued expenses and other current liabilities on the Unaudited Condensed Consolidated Balance Sheets.

Business Combination

Business Combination	9 Months Ended
	Sep. 30, 2021
Business Combinations [Abstract]
Business Combination	Note 4. Business Combination World Energy On May 17, 2021, the Company acquired all of the issued and outstanding membership interests of World Energy, a privately-held, Massachusetts-based entity, and retained two of its principals and all of World Energy’s employees. World Energy is a direct-install energy efficiency services company (“ESCO”), serving commercial, industrial and institutional customers. World Energy enables utilities to meet their energy savings mandates by developing and executing energy efficiency projects. The acquisition of World Energy expands the Company’s ability to deliver a comprehensive suite of energy savings services that enhances XL Grid’s solutions portfolio to include commercial and industrial EV charging, solar, and energy management services. The total purchase price consideration, as adjusted, is $12,461 for the acquisition of World Energy. During the three months ended September 30, 2021, the Company remitted to the sellers of World Energy additional cash of $76 in connection with the finalization of working capital adjustments. The as adjusted purchase price consisted of the following components: Cash of $8,496, as adjusted, consisting of the contractual purchase price of $8,000, plus working capital adjustments of an aggregate of $496. ● The closing date issuance of 231,002 shares of the Company’s common stock, valued at the closing price of $6.23 per share as of May 17, 2021, for a total share fair value upon issuance of $1,439; ● An obligation to issue 244,956 shares of the Company’s common stock to certain of the sellers and their advisors of World Energy, in three equal installments on the sixth, twenty-fourth and the thirtieth monthly anniversaries of the closing date. The closing date fair value was recorded at an aggregate amount of $1,526; ● An obligation to pay in cash an earnout of $1,000 upon World Energy’s achievement for the calendar year 2021 revenues of $19,500. The payment of the earnout is due within 30 days following the completion of the audit of XL Fleet’s financial statements for the fiscal year ending December 31, 2021. Pursuant to the agreement, the earnout is payable only if revenues for the period equal or exceed $19,500. Should the World Energy revenues be less than $19,500, then the earnout would be $0. The Company determined that the achievement of the $19,500 revenue target was highly probable, and as such, the Company recorded a closing date fair value of the earnout in the amount of $1,000. Adjustments to the initial purchase accounting for the acquisition will be completed, as needed, up to one year from the acquisition date as the Company obtains additional information regarding facts and circumstances that existed as of the acquisition date. The following details the preliminary allocation of the purchase price consideration: Cash $ 8,000 Working capital adjustments 496 Fair value of 231,002 shares issued at closing 1,439 Fair value of the earnout 1,000 Portion of deferred obligation to issue shares of common stock 1,526 Total consideration 12,461 Less the fair value of assets acquired less liabilities assumed (4,109 ) Goodwill $ 8,352 Included in assets acquired was cash of $308. In connection with the acquisition of World Energy, the Company incurred an additional obligation to issue shares of its common stock to the three sellers, two of which also entered into employment agreements with the Company. Pursuant to the terms of the agreement, the Company is obligated to issue 448,050 shares of its common stock, with an aggregate fair value of approximately $2,800 as of September 30, 2021, issuable in three equal installments on the sixth, twenty-fourth and the thirtieth monthly anniversaries of the closing date, provided that seller/employee is employed by the Company at the date of issuance. If the seller/employee is not employed at such issuance date, the shares attributable to that seller/employee are forfeited. The Company determined that under relevant accounting guidance that this obligation to issue shares would be accounted for as compensation and not as purchase price consideration. Accordingly, the fair values of each of the three compensation share obligations are accreted as compensation over each relevant compensation period, and for the three and nine months ended September 30, 2021, the Company recorded as selling, general and administration expense, compensation costs of $573 and $1,000, respectively. The initial transaction with World Energy included an outstanding PPP loan of $507 that was incorporated in the liabilities assumed. During the third quarter of 2021, the PPP loan was forgiven in full which resulted in an additional payment to the sellers of World Energy. Consequently, the fair value of assets acquired less liabilities assumed was adjusted by the entire amount of the PPP loan that was forgiven, with a corresponding reduction in goodwill. The Company has accounted for this acquisition as a business combination under ASC Topic 805 “Business Combinations.” The acquisition method requires, among other things, that assets acquired and liabilities assumed in a business combination be recognized at their fair values as of the acquisition date. The fair values of the assets acquired and liabilities assumed by major class were recognized as follows: Amount Cash $ 308 Accounts receivable 3,350 Inventory, net 1,282 Prepaid expenses and other current assets 100 Property and equipment, net 173 Intangible assets, net 1,560 Right-of-use asset 145 Goodwill 8,352 Other assets 12 Accounts payable (1,096 ) Lease liability, current (56 ) Accrued expenses and other current liabilities (1,297 ) Deferred revenue (283 ) Lease liability, non-current (89 ) Total purchase consideration $ 12,461 The acquired intangible assets are comprised of $1,560 related to the fair value of customer relationships which is amortized over three years. The estimated fair value of the intangible asset acquired was determined based on the income approach to measure the fair value of the customer relationships. This fair value measurement was based on significant inputs not observable in the market and thus represents a Level 3 measurement within the fair value hierarchy. Goodwill represents the excess of the purchase consideration over the estimated acquisition date fair value of the net tangible and intangible assets acquired. Goodwill is primarily attributable to expected post-acquisition synergies from integrating World Energy’s assembled workforce, products and processes into the Company’s product offerings. Goodwill recorded is not deductible for income tax purposes. Supplemental disclosure of pro forma information: The following unaudited pro forma financial information presents the combined results of the operations of XL Fleet and World Energy as if the acquisition of World Energy had occurred as of January 1, 2020. The unaudited pro forma financial information is not necessarily indicative of what the condensed consolidated results of operations actually would have been had the respective acquisitions been completed on January 1, 2020. In addition, the unaudited pro forma financial information does not purport to project the future results of operations of the combined Company. Since the merger was consummated on May 17, 2021, the results of the merger are fully incorporated into the condensed consolidated financial information for the three months ended September 30, 2021. Three Months Nine Months 2020 2021 2020 Revenues $ 10,971 $ 15,318 $ 21,003 Net (loss) income $ (1,630 ) $ 44,741 $ (22,194 ) Per share amounts: Net (loss) income per share – basic $ (0.02 ) $ 0.32 $ (0.27 ) Net loss per share – diluted $ (0.02 ) $ 0.31 $ (0.27 ) The above pro forma information includes pro forma adjustments to remove the effect of the following non-recurring transactions: 1.) Non-recurring merger expenses of $498 were added back for the nine months ended September 30, 2021. 2.) Elimination of interest expense associated with debt that was repaid in the acquisition of World Energy of $37 for the nine months ended September 30, 2021, and $23 and $64 for the three and nine months ended September 30, 2020, respectively.

Purchase of Convertible Note

Purchase of Convertible Note	9 Months Ended
	Sep. 30, 2021
Purchase of Convertible Note [Abstract]
Purchase of Convertible Note	Note 5. Purchase of Convertible Note On July 15, 2021, XL Fleet made an investment of $3,000 into eNow, a developer of solar and battery power systems that will enable fully-electric transport refrigeration units (“eTRUs”) for Class 8 commercial trailers. In exchange for the investment, eNow issued to the Company a convertible debenture (the “eNow Convertible Note”) dated July 15, 2021 (the “Issuance Date”) in the original principal amount of $3,000. The eNow Convertible Note bears interest at the rate of 8% per annum. The eNow Convertible Note is classified as an available-for-sale security. As discussed below, XL Fleet has an option to purchase eNow. If XL Fleet does not exercise this option, under certain circumstances the eNow Convertible Note would be converted on such date into Series B preferred stock. Interest on the outstanding principal sum of the eNow Convertible Note commences accruing on the Issuance Date and is computed on the basis of a 365-day year. Pursuant to the terms of the eNow Convertible Note agreement, XL Fleet has the right to acquire eNow at a pre-determined valuation and has a right of first refusal with respect to competing offers to acquire eNow, which, if unexercised, will expire on December 31, 2021. In addition to the terms described above, on July 15, 2021 (“Effective Date”), XL Fleet entered into a Development and Supply Agreement (the “Development and Supply Agreement”) with eNow, whereby XL Fleet is made the exclusive provider of high voltage batteries and associated power systems for use in eNow eTRUs. For additional details, see analysis of the fair value of the investment in the eNow Convertible Note in Note 9.

Accrued Expenses and Other Curr

Accrued Expenses and Other Current Liabilities	9 Months Ended
	Sep. 30, 2021
Accrued Expenses and Other Current Liabilities [Abstract]
Accrued Expenses and Other Current Liabilities	Note 6. Accrued Expenses and Other Current Liabilities Accrued expenses and other current liabilities consisted of the following at September 30, 2021 and December 31, 2020: As of September 30, December 31, 2021 2020 Accrued warranty costs $ 1,601 $ 1,735 Accrued compensation and related benefits 3,385 1,001 Contingent purchase price consideration – Quantum 1,911 926 Deferred purchase price consideration – World Energy 1,503 - Accreted contingent compensation to sellers – World Energy 1,000 - Accrued financing fees - 723 Professional fees 940 - Accrued expenses, other 2,614 216 $ 12,954 $ 4,601

ROU Assets and Lease Liabilitie

ROU Assets and Lease Liabilities	9 Months Ended
	Sep. 30, 2021
Regulatory Assets and Liabilities Disclosure [Abstract]
ROU Assets and Lease Liabilities	Note 7. ROU Assets and Lease Liabilities XL Fleet has entered into operating and finance leases as the lessee for office space, R&D and manufacturing facilities, and vehicles. On January 1, 2021 (“Effective Date”), the Company adopted FASB Accounting Standards Codification, or ASC, Topic 842, Leases (“ASC 842”), which increases transparency and comparability by recognizing a lessee’s rights and obligations resulting from leases by recording them on the balance sheet as lease assets and lease liabilities. The new guidance requires the recognition of the right-of-use (“ROU”) assets and related operating and finance lease liabilities on the balance sheet. The Company adopted the new guidance using the modified retrospective approach on January 1, 2021. As a result, the consolidated balance sheet as of December 31, 2020 was not restated and is not comparative. The adoption of ASC 842 resulted in the recognition of operating ROU assets of $3,481 and operating lease liabilities of $3,481 on the Company’s condensed consolidated balance sheet as of January 1, 2021. The adoption of ASC 842 resulted in the recognition of finance ROU assets of $897 and finance lease liabilities of $897 on the Company’s condensed consolidated balance sheet as of January 1, 2021. The Company elected the package of practical expedients permitted within the standard, which allow an entity to forgo reassessing (i) whether a contract contains a lease, (ii) classification of leases, and (iii) whether capitalized costs associated with a lease meet the definition of initial direct costs. Also, the Company elected the expedient allowing an entity to use hindsight to determine the lease term and impairment of ROU assets and the expedient to allow the Company to not have to separate lease and non-lease components. The Company has also elected the short-term lease accounting policy under which the Company would not recognize a lease liability or ROU asset for any lease that at the commencement date has a lease term of twelve months or less and does not include a purchase option that the Company is more than reasonably certain to exercise. For contracts entered into on or after the Effective Date, at the inception of a contract the Company will assess whether the contract is, or contains, a lease. The Company’s assessment is based on: (i) whether the contract involves the use of a distinct identified asset, (ii) whether the Company obtained the right to substantially all the economic benefit from the use of the asset throughout the period, and (iii) whether the Company has the right to direct the use of the asset. Leases entered into prior to January 1, 2021, which were accounted for under ASC 840, were not reassessed for classification. For operating leases, the lease liability is initially and subsequently measured at the present value of the unpaid lease payments. For finance leases, the lease liability is initially measured in the same manner and date as for operating leases, and is subsequently presented at amortized cost using the effective interest method. The Company generally uses its incremental borrowing rate as the discount rate for leases, unless an interest rate is implicitly stated in the lease. The present value of the lease payments is calculated using the incremental borrowing rate for operating and finance leases, which was determined using a portfolio approach based on the rate of interest that the Company would have to pay to borrow an amount equal to the lease payments on a collateralized basis over a similar term. The lease term for all of the Company’s leases includes the noncancelable period of the lease plus any additional periods covered by either a Company option to extend the lease that the Company is reasonably certain to exercise, or an option to extend the lease controlled by the lessor. All ROU assets are reviewed periodically for impairment. Lease expense for operating leases consists of the lease payments plus any initial direct costs and is recognized on a straight-line basis over the lease term. Lease expense for finance leases consists of the amortization of the asset on a straight-line basis over the shorter of the lease term or its useful life and interest expense determined on an amortized cost basis, with the lease payments allocated between a reduction of the lease liability and interest expense. The Company’s operating leases are comprised primarily of office space and R&D and manufacturing facilities. Finance leases are comprised primarily of vehicle leases. Balance sheet information related to our leases is presented below (ASC 842 was adopted on January 1, 2021): September 30, January 1, December 31, Operating leases: Right-of-use assets $ 3,219 $ 3,481 $ – Lease liability, current 433 469 – Lease liability, non-current 2,841 3,012 – Finance leases: Right-of-use assets 1,252 897 – Lease liability, current 446 265 – Lease liability, non-current 685 632 – Other information related to leases is presented below: Three Months Ended September 30, Nine Months Ended September 30, 2021 2021 Other information: Operating lease cost $ 222 $ 617 As of 2021 Operating cash flows from operating leases $ 561 Weighted-average remaining lease term – operating leases (in months) 86.8 Weighted-average discount rate – operating leases 9.6 % As of September 30, 2021, the annual minimum lease payments of our operating lease liabilities were as follows: For The Years Ending December 31, 2021 (excluding the nine months ended September 30, 2021) $ 214 2022 673 2023 633 2024 597 2025 613 Thereafter 1,891 Total future minimum lease payments, undiscounted 4,621 Less: imputed interest (1,347 ) Present value of future minimum lease payments $ 3,274

Note Payable

Note Payable	9 Months Ended
	Sep. 30, 2021
Debt Disclosure [Abstract]
Note Payable	Note 8. Note Payable Paycheck Protection Program Loan In March 2021, World Energy entered into a Promissory Note (the “PPP Note”) with Boston Private Bank & Trust Company as the lender (the “Lender”), pursuant to which the Lender agreed to make a loan to the Company under the Paycheck Protection Program (the “PPP Loan”) offered by the U.S. Small Business Administration (the “SBA”) in a principal amount of $507 pursuant to Title 1 of the Coronavirus Aid, Relief and Economic Security Act (the “CARES Act”). This loan was forgiven by the SBA during July 2021 (See Note 4).

Fair Value Measurements

Fair Value Measurements	9 Months Ended
	Sep. 30, 2021
Fair Value Disclosures [Abstract]
Fair Value Measurements	Note 9. Fair Value Measurements Mark-to-Market Measurement The investment in the eNow Convertible Note was valued based upon a revenue multiple enterprise valuation. The contingent consideration related to the acquisition of Quantum Fuel Systems LLC (“Quantum”) was valued based upon the present value of the expected contingent consideration. The fair value of obligation to issue shares of common stock to the sellers of World Energy was based on the closing price of XL’s Common Stock on the reporting date. The Public Warrants were traded under the symbol XL.WS and the fair values were based upon the closing price of the Public Warrants at each measurement date. The Private Warrants were valued using a Black-Scholes model, pursuant to the inputs provided in the table below: Mark-to-Market Measurement at Mark-to-Market Measurement at September 30, December 31, Input 2021 2020 Risk-free rate 0.81 % 0.36 % Remaining term in years 4.23 4.98 Expected volatility 87.9 % 95.4 % Exercise price $ 11.50 $ 11.50 Fair value of common stock $ 6.16 $ 23.73 The following table sets forth the Company’s assets and liabilities which are measured at fair value on a recurring basis by level within the fair value hierarchy: Fair Value Measurements as of Level I Level II Level III Total Asset: Investment in eNow Convertible Note $ - $ - $ 3,000 $ 3,000 Liability:. Private Warrants $ - $ - $ 13,582 $ 13,582 Contingent consideration -– Quantum $ - $ - $ 1,911 $ 1,911 Earnout – World Energy $ - $ - $ 1,000 $ 1,000 Fair value of obligation to issue shares of common stock to sellers of World Energy $ - $ - $ 1,509 $ 1,509 Fair Value Measurements as of Level I Level II Level III Total Liability: Public Warrants $ 62,100 $ - $ - $ 62,100 Private Warrants $ - $ - $ 81,195 $ 81,195 Contingent consideration -– (Quantum) $ - $ - $ 1,849 $ 1,849 During the nine months ended September 30, 2021, 7,441,020 Public Warrants were exercised, which resulted in the issuance of 7,441,020 shares of the Company’s Common Stock, generating cash proceeds of $85,555 and 225,647 Public Warrants were called at $0.01 per warrant. No Public Warrants remain outstanding as of September 30, 2021. The following is a roll forward of the Company’s Level 3 instruments: As of Asset Liability Balance, January 1, 2021 $ - $ 83,044 Obligation to issue shares of common stock to sellers of World Energy - 1,526 Fair value adjustment – Quantum contingent consideration - 62 Fair value adjustments – Warrant liability - (67,612 ) Fair value adjustments – World Energy - (18 ) Purchase of eNow Convertible Note at fair value 3,000 - Earnout – World Energy - 1,000 Balance, September 30, 2021 $ 3,000 $ 18,002

Warrants

Warrants	9 Months Ended
	Sep. 30, 2021
Warrants [Abstract]
Warrants	Note 10. Warrants Legacy XL Common Stock Warrants: During the nine months ended September 30, 2021, 243,000 Legacy XL Warrants were exercised, which resulted in the issuance of 233,555 shares of the Company’s common stock, in a cashless exercise. A summary of the warrant activity for the nine months ended September 30, 2021 was as follows: Weighted Average Warrants Shares Exercise Price Outstanding at January 1, 2021 249,117 $ 0.76 Issued - - Exercised (243,000 ) 0.76 Outstanding at September 30, 2021 6,117 $ 0.76 Exercisable at September 30, 2021 6,117 $ 0.76

Share-Based Compensation Expens

Share-Based Compensation Expense	9 Months Ended
	Sep. 30, 2021
Share-based Payment Arrangement [Abstract]
Share-Based Compensation Expense	Note 11. Share-Based Compensation Expense Share-based compensation expense for stock options, restricted stock awards and restricted stock units for the three months ended September 30, 2021 and 2020 was $1,194 and $386, respectively, and $2,390 and $663 for the nine months ended September 30, 2021 and 2020, respectively. As of September 30, 2021, there was $9,507 of unrecognized compensation cost related to stock options which is expected to be recognized over the remaining vesting periods, with a weighted-average period of 3.3 years. Stock Options During the nine months ended September 30, 2021, the Company issued 776,116 options to certain employees and board members that will vest over a period of one to four years. A summary of stock option award activity for the nine months ended September 30, 2021 was as follows: Options Shares Weighted Weighted Average Outstanding at December 31, 2020 10,975,224 $ 0.57 7.6 Granted 776,116 8.56 Exercised (133,083 ) 0.24 Cancelled or forfeited (559,102 ) 0.65 Outstanding at September 30, 2021 11,059,155 $ 1.01 6.8 Exercisable at September 30, 2021 7,374,132 $ 0.39 6.0 The aggregate intrinsic value of stock options outstanding as of September 31, 2021 was $53,038. The aggregate intrinsic value of stock options exercisable as of September 31, 2021 was $38,998. Cash received from options exercised for the nine months ended September 30, 2021 and 2020 was $32 and $21, respectively. Restricted Stock Awards The fair value of restricted stock awards is estimated by the fair value of the Company’s Common Stock at the date of grant. Restricted stock activity during the nine months ended at September 30, 2021 was as follows: Number of Shares Weighted Average Grant Date Fair Value Per Share Non-vested, at beginning of period 446,332 $ 0.24 Granted - - Vested - - Cancelled or forfeited - Non-vested, at end of period 446,332 $ 0.24 Restricted Stock Units During the nine months ended September 30, 2021, the Company issued 476,050 restricted stock units to certain employees and board members that will vest over a period of one to four years. The fair value of restricted stock unit awards is estimated by the fair value of the Company’s Common Stock at the date of grant. Restricted stock activity during the nine months ended at September 30, 2021 was as follows: Number of Weighted Non-vested, at beginning of period - $ - Granted 476,050 7.08 Vested - - Cancelled or forfeited (4,319 ) 6.49 Non-vested, at end of period 471,731 $ 7.08

Related Party Transactions

Related Party Transactions	9 Months Ended
	Sep. 30, 2021
Related Party Transactions [Abstract]
Related Party Transactions	Note 12. Related Party Transactions Operating lease: Rent expense under the operating lease for the three months ended September 30, 2021 and 2020 was $58 and $58, respectively, and $173 and $173 for the nine months ended September 30, 2021 and 2020, respectively. Future minimum lease payments for this lease are as follows: 2021 (Three months) $ 58 2022 39 Total $ 97

Commitments and Contingencies

Commitments and Contingencies	9 Months Ended
	Sep. 30, 2021
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Note 13. Commitments and Contingencies Sponsorship Commitment: Equipment Purchase: Purchase Commitments: Legal proceedings: On March 8, 2021, a putative class action complaint was filed in federal district court for the Southern District of New York (Suh v. XL Fleet Corp., et al., Case No. 1:21-cv-02002) against the Company and certain of its current officers and directors. On March 12, 2021, a second putative class action complaint was filed in federal district court for the Southern District of New York (Kumar v. XL Fleet Corp., et al., Case No. 1:21-cv-02171) against the Company and certain of its current officers and directors. Those cases were consolidated and a lead plaintiff appointed in June 2021, and an amended complaint filed on July 20, 2021 alleging that certain public statements made by the defendants between October 2, 2020 and March 2, 2021 violated Sections 10(b) and 20(a) of the Securities Exchange Act of 1934 and Rule 10b-5 promulgated thereunder. The Company believes that the allegations asserted in the amended complaint are without merit, and the Company intends to vigorously defend the lawsuit. There can be no assurance, however, that the Company will be successful. At this time, the Company is unable to estimate potential losses, if any, related to the lawsuit. On September 20, 2021, the Laidlaw Complaint was filed in the Delaware Court of Chancery against certain of the Company’s current officers and directors, and the Company’s sponsor, Pivotal Investment Holdings II LLC. The Laidlaw Complaint alleges various breaches of fiduciary duty, and aiding and abetting breaches of fiduciary duty, for purported actions relating to the negotiation and approval of the December 21, 2020 merger and organization of legacy XL to become XL Fleet Corp., and purportedly materially misleading statements made in connection with the merger. The Company believes that the allegations asserted in the Laidlaw Complaint are without merit, and the Company intends to vigorously defend the lawsuit. On October 19, 2021, the Janmohamed Complaint was filed in the Delaware Court of Chancery against certain of the Company’s current officers and directors, and the Company’s sponsor, Pivotal Investment Holdings II LLC. The Janmohamed Complaint alleges various breaches of fiduciary duty, and aiding and abetting breaches of fiduciary duty, for purported actions relating to the negotiation and approval of the December 21, 2020 merger and organization of legacy XL to become XL Fleet Corp., and purportedly materially misleading statements made in connection with the merger. The Company believes that the allegations asserted in the Janmohamed Complaint are without merit, and the Company intends to vigorously defend the lawsuit.

Net (Loss) Income Per Share

Net (Loss) Income Per Share	9 Months Ended
	Sep. 30, 2021
Earnings Per Share [Abstract]
Net (Loss) Income Per Share	Note 14. Net (Loss) Income Per Share The following is a reconciliation of the numerator and denominator used to calculate basic earnings per share and diluted earnings per share for the three and nine months ended September 30, 2021, and 2020: Three Months Ended Nine Months Ended 2021 2020 2021 2020 Numerator: Net (loss) income $ (7,531 ) $ (2,277 ) $ 43,914 $ (22,230 ) Denominator: Weighted average shares outstanding, basic 139,392,170 83,299,127 138,082,355 82,820,099 Dilutive effect of options, warrants, and restricted stock units - - 10,386,753 - Weighted average shares outstanding, diluted 139,392,170 83,299,127 148,469,108 82,820,099 Net (loss) income per share, basic $ (0.05 ) $ (0.03 ) $ 0.32 $ (0.27 ) Net (loss) income per share, diluted $ (0.05 ) $ (0.03 ) $ 0.30 $ (0.27 ) Potential dilutive securities, which include stock options, warrants and restricted stock units have been excluded from the computation of diluted net loss per share for the three months ended September 30, 2021 and the three and nine months ended September 30, 2020 as the effect would be to reduce the net loss per share. Therefore, for this period the weighted average number of common shares outstanding used to calculate both basic and diluted net loss per share is the same. The number of shares underlying outstanding dilutive securities which have been excluded from the computation of diluted net loss per share above, are presented below: Three Months Ended Nine Months Ended 2021 2020 2021 2020 Stock options 11,059,155 10,793,122 173,166 10,793,122 Private Warrants 4,233,333 - 4,233,333 - XL Legacy Warrants 6,117 2,139,593 - 2,139,593 Restricted stock units 471,731 - - - Total 15,770,336 12,932,715 4,406,499 12,932,715

Retirement Plan

Retirement Plan	9 Months Ended
	Sep. 30, 2021
Retirement Benefits [Abstract]
Retirement Plan	Note 15. Retirement Plan The Company has adopted a 401(k) plan to provide all eligible employees a means to accumulate retirement savings on a tax-advantaged basis. The 401(k) plan requires participants to be at least 21 years old. In addition to the traditional 401(k), eligible employees are given the option of making an after- tax contribution to a Roth 401(k) or a combination of both. Plan participants may make before tax elective contributions up to the maximum percentage of compensation and dollar amount allowed under the Internal Revenue Code. Participants are allowed to contribute, subject to IRS limitations on total annual contributions from 1% to 90% of eligible earnings. The plan provides for automatic enrollment at a 3% deferral rate of an employee’s eligible wages. The Company provides for safe harbor matching contributions equal to 100% on the first 3% of an employee’s eligible earnings deferred and an additional 50% on the next 2% of an employee’s eligible earnings deferred. Employee elective deferrals and safe harbor matching contributions are 100% vested at all times. In connection with the acquisition of World Energy, XL Fleet adopted the World Energy 401(k) plan whose features are the same as those of the XL Fleet 401(k) plan except that (i) Participants are allowed to contribute, subject to IRS limitations on total annual contributions from 1% to 100% of eligible earnings and (ii) the safe harbor non-elective contribution is equal to 3% of employee’s compensation.

Subsequent Events

Subsequent Events	9 Months Ended
	Sep. 30, 2021
Subsequent Events [Abstract]
Subsequent Events	Note 16. Subsequent Event Management has reviewed material events subsequent of the period ended September 30, 2021 and prior to the filing of financial statements in accordance with FASB ASC 855 “Subsequent Events”. Hiring of CEO

Accounting Policies, by Policy

Accounting Policies, by Policy (Policies)	9 Months Ended
	Sep. 30, 2021
Accounting Policies [Abstract]
Basis of consolidated financial statement presentation	Basis of consolidated financial statement presentation:
Use of estimates	Use of estimates:
Concentration of Credit Risk	Concentration of Credit Risk: With respect to trade receivables, the Company routinely assesses the financial strength of its customers and, as a consequence, believes that the receivable credit risk exposure is limited. As of September 30, 2021, two customers accounted for approximately 48% and 21% of accounts receivable. As of December 31, 2020, one customer accounted for approximately 82% of accounts receivable. For the three months ended September 30, 2021 and 2020, two customers and two customers accounted for approximately 80% and 73% of revenues, respectively. For the nine months ended September 30, 2021 and 2020, two customers and two customers accounted for approximately 56% and 69% of revenues, respectively.
Cash, cash equivalents, and restricted cash	Cash, cash equivalents, and restricted cash: Restricted cash held at both September 30, 2021 and December 31, 2020, consists of $150 for a bank deposit required for a letter of credit which is reserved for the Company’s California lease. The following table provides a reconciliation of cash, cash equivalents, and restricted cash in the condensed consolidated balance sheets to the total amount shown in the condensed consolidated statements of cash flows: As of September 30, 2021 2020 Cash and cash equivalents $ 366,748 $ 1,583 Restricted cash 150 150 Total cash, cash equivalents, and restricted cash $ 366,898 $ 1,733
Accounts receivable, net	Accounts receivable, net:
Inventory, net	Inventory, net:
Fair value measurements	Fair value measurements: The fair value of the Company’s financial assets and liabilities reflects management’s estimate of amounts that the Company would have received in connection with the sale of the assets or paid in connection with the transfer of the liabilities in an orderly transaction between market participants at the measurement date. In connection with measuring the fair value of its assets and liabilities, the Company seeks to maximize the use of observable inputs (market data obtained from independent sources) and to minimize the use of unobservable inputs (internal assumptions about how market participants would price assets and liabilities). The following fair value hierarchy is used to classify assets and liabilities based on the observable inputs and unobservable inputs used in order to value the assets and liabilities: Level 1 Level 2 Level 3 An asset’s or liability’s fair value measurement level within the fair value hierarchy is based on the lowest level of any input that is significant to the fair value measurement. Valuation techniques used need to maximize the use of observable inputs and minimize the use of unobservable inputs. See Note 9 for additional information on assets and liabilities measured at fair value. The Company believes its valuation methods are appropriate and consistent with other market participants, however the use of different methodologies or assumptions to determine the fair value of certain financial instruments could result in a different fair value measurement at the reporting date. The Company’s financial instruments consist of cash and cash equivalents, restricted cash, accounts receivable, accounts payable, accrued liabilities, contingent consideration liability, long-term debt and warrant liability. The carrying value of cash and cash equivalents, accounts receivable, accounts payable, and accrued expenses approximates fair value because of the short-term nature of those instruments.
Prepaid expenses and other current assets	Prepaid expenses and other current assets:
Revenue	Revenue: Revenue is recognized upon transfer of control to the customer, which occurs when the Company has a present right to payment, legal title has passed to the customer, the customer has the significant risks and rewards of ownership, and where acceptance is not a formality, the customer has accepted the product or service. For the Drive Systems products, in general, transfer of control is upon shipment of the equipment as the terms are FOB shipping point or equivalent, as the Company has no other promised goods or services in its contracts with customers. In limited instances, the Company provides installation services to end-user fleet customers related to the purchased hybrid electric powertrain equipment. When provided, these installation services are not distinct within the context of the contract due to the fact that the end-use fleet customer is purchasing a completed modification to its vehicles and therefore, the installation services involve significant integration to integrate the hybrid electric powertrain equipment with the customer’s vehicle. As a result, the hybrid electric powertrain equipment and installation services represent a single performance obligation within these contracts with customers. The Company recognizes the revenue for the equipment sale and installation service for Drive System products at the same time, which is after the installation is complete. The Company has elected to treat shipping and handling activities related to contracts with channel partner customers for Drive System products as costs to fulfill the promise to transfer the associated equipment and not as a separate performance obligation. For the XL Grid solutions, in general, transfer of control is upon the acceptance and certification of project completion by both the end customer and the utility who is funding the energy incentives, representing a single performance obligation of the Company. Due to the short-term nature of projects (typically two to three weeks), the Company recognizes revenues from all XL Grid solutions activities at a point in time, when persuasive evidence of an arrangement exists, delivery has occurred, the price is fixed or determinable and the Company has the right to payment for the transferred asset. The Company also assesses multiple contracts entered into by the same customer in close proximity to determine if the contracts should be combined for revenue recognition purposes. During the duration of a project for XL Grid solutions, all direct material and labor costs and those indirect costs related to the project are capitalized, and customer deposits are treated as liabilities. Once a project has been completed and the energy efficiency upgrades have been deemed to meet client specifications, capitalized costs are charged to earnings. For both Drive Systems and XL Grid solutions, when the Company’s contracts with customers contain multiple performance obligations, which is infrequent, the contract transaction price is allocated on a relative standalone selling price (SSP) basis to each performance obligation. The Company determines standalone selling prices based on observable selling prices for the sale of its systems. For extended warranties, the Company determines SSP based on expected cost plus margin. The Company establishes the margin based on review of market conditions and margins obtained by market participants for similar services. Any allocation of the transaction price required is determined at the contracts’ inception. The transaction price is the amount of consideration to which the Company expects to be entitled in exchange for transferring goods and services to the customer. Revenue is recorded based on the transaction price, which is solely made up of fixed consideration for its products and services. The Company does not adjust transaction price for the effects of a significant financing component when the period between the transfer of the promised good or service to the customer and payment for that good or service by the customer is expected to be one year or less. The Company has not identified any significant financing components to date. The Company’s sales can in certain instances include non-cash consideration in the form of the customer transferring to the Company, the customer’s rights to cash incentives from programs administered by municipalities related to hybrid vehicle programs that a customer is entitled to as a result of its purchase. The incentives are fixed amounts that are readily determinable. The Company values the non-cash consideration at its fair value, which generally is the amount of the incentive. Payment terms on invoices range from 30 to 60 days. The Company excludes from revenue any sales tax and other government-assessed and imposed taxes on revenue generating activities that are invoiced to customers. The Company has elected to apply the practical expedient to expense costs to obtain contracts, which principally relate to sales commissions, at the time the liability is incurred when the expected amortization period is one year or less.
Warranties	Warranties Customers who purchase the Drive Systems are provided limited-assurance-type warranties for equipment and work performed under the contracts. The warranty period typically extends for 3 years following transfer of control of the equipment. The warranties solely relate to correction of product defects during the warranty period, which is consistent with similar warranties by offered by competitors. Therefore, the Company has determined that these warranties are outside the scope of ASC 606 and will continue to be accounted for under ASC 460, Guarantees. Customers of XL Grid solutions are provided limited-assurance-type warranties for a term of one year for installation work performed under its contracts. Warranties for equipment sold to customers are provided by the original equipment manufacturers. For both Drive Systems and XL Grid solutions, the Company accrues the estimated cost of product warranties for unclaimed charges based on historical experiences and expected results. Should product failure rates and material usage costs differ from these estimates revisions to the estimated warranty liability would be required. The Company periodically assesses the adequacy of its recorded product warranty liabilities and adjusts the balances as required. Warranty expense is recorded as a component of cost of product revenue in the statements of operations.
Share-based compensation	Share-based compensation: Stock Options The Company accounts for stock-based compensation related to these awards based on the fair value of the awards. The Company uses the Black-Scholes option pricing model to determine the fair value of stock-based awards, and recognizes the compensation cost on a straight line basis over the requisite service period of the awards for employee, which is typically the four-year vesting period of the award, and effective contract period specified in the award agreement for non-employee. The fair value of common stock is determined based on the closing price on the New York Stock Exchange at each award grant date. The determination of the fair value of share-based payment awards utilizing the Black-Scholes model is affected by the stock price and a number of assumptions, including expected volatility, expected life, risk- free interest rate and expected dividends. The Company does not have a history of trading in its common stock as it was not a public company until December 21, 2020, and as such volatility was estimated using historical volatilities of comparable public entities. The expected life of the awards is estimated based on a simplified method, which uses the average of the vesting term and the original contractual term. The risk-free interest rate assumption is based on observed interest rates appropriate for the expected life of the awards. The dividend yield assumption is based on history and expectation of paying no dividends. Forfeitures are accounted for as they occur. The fair value of stock options issued for the nine months ended September 30, 2021 and 2020 was measured with the following assumptions: For the Nine Months Ended 2021 2020 Expected volatility 78.1 – 88.2 % 80.0 – 80.1 % Expected term (in years) 6.25 6.25 Risk-free interest rate 0.4 – 1.9 % 0.1 – 0.2 % Expected dividend yield 0.0 % 0.0 % Restricted Stock Units Restricted stock units generally vest over the requisite service periods (vesting on a straight–line basis). The fair value of a stock award is equal to the fair market value of a share of the Company’s Common stock on the grant date. The Company accounts for the forfeiture of equity awards as they occur.
Warrant Liabilities	Warrant Liabilities:
Research and development expense:	Research and development expense:
Net income (loss) per share	Net income (loss) per share:
Segment Information	Segment Information:
Related parties	Related parties:
Recent accounting pronouncements issued and adopted	Recent accounting pronouncements issued and adopted: In December 2019, the FASB issued ASU 2019-12, Income Taxes (Topic 740): Simplifying the Accounting for Income Taxes

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Tables)	9 Months Ended
	Sep. 30, 2021
Accounting Policies [Abstract]
Schedule of reconciliation of cash, cash equivalents, and restricted cash	As of September 30, 2021 2020 Cash and cash equivalents $ 366,748 $ 1,583 Restricted cash 150 150 Total cash, cash equivalents, and restricted cash $ 366,898 $ 1,733
Schedule of fair value of stock options issued	For the Nine Months Ended 2021 2020 Expected volatility 78.1 – 88.2 % 80.0 – 80.1 % Expected term (in years) 6.25 6.25 Risk-free interest rate 0.4 – 1.9 % 0.1 – 0.2 % Expected dividend yield 0.0 % 0.0 %

Revenue (Tables)

Revenue (Tables)	9 Months Ended
	Sep. 30, 2021
Revenue from Contract with Customer [Abstract]
Schedule of disaggregation of revenue	Three Months Ended September 30, Nine Months Ended September 30, 2021 2020 2021 2020 Revenue from the sale of Drive Systems: Revenue direct to customers $ 366 $ 959 $ 1,138 $ 2,020 Revenue through channel partners 189 5,369 1,374 7,452 Revenue from the sale of XL Grid solutions – which are sold direct to customers 2,645 - 5,057 - Total revenue $ 3,200 $ 6,328 $ 7,569 $ 9,472
Schedule of accrued warranty liability	For the September 30, For the Ended December 31, 2020 2021 Balance at the beginning of the period $ 1,735 $ 1,009 Acquisition date accrual for World Energy acquisition 25 - Accrual for warranties issued 126 912 Warranty fulfillment charges (285 ) (186 ) Balance at the end of the period $ 1,601 $ 1,735

Business Combination (Tables)

Business Combination (Tables)	9 Months Ended
	Sep. 30, 2021
Business Combinations [Abstract]
Schedule of purchase price consideration	Cash $ 8,000 Working capital adjustments 496 Fair value of 231,002 shares issued at closing 1,439 Fair value of the earnout 1,000 Portion of deferred obligation to issue shares of common stock 1,526 Total consideration 12,461 Less the fair value of assets acquired less liabilities assumed (4,109 ) Goodwill $ 8,352
Schedule of fair values of the assets acquired and liabilities assumed by major class	Amount Cash $ 308 Accounts receivable 3,350 Inventory, net 1,282 Prepaid expenses and other current assets 100 Property and equipment, net 173 Intangible assets, net 1,560 Right-of-use asset 145 Goodwill 8,352 Other assets 12 Accounts payable (1,096 ) Lease liability, current (56 ) Accrued expenses and other current liabilities (1,297 ) Deferred revenue (283 ) Lease liability, non-current (89 ) Total purchase consideration $ 12,461
Schedule of supplemental disclosure of pro forma information	Three Months Nine Months 2020 2021 2020 Revenues $ 10,971 $ 15,318 $ 21,003 Net (loss) income $ (1,630 ) $ 44,741 $ (22,194 ) Per share amounts: Net (loss) income per share – basic $ (0.02 ) $ 0.32 $ (0.27 ) Net loss per share – diluted $ (0.02 ) $ 0.31 $ (0.27 )

Accrued Expenses and Other Cu_2

Accrued Expenses and Other Current Liabilities (Tables)	9 Months Ended
	Sep. 30, 2021
Accrued Expenses and Other Current Liabilities [Abstract]
Schedule of accrued expenses and other current liabilities	As of September 30, December 31, 2021 2020 Accrued warranty costs $ 1,601 $ 1,735 Accrued compensation and related benefits 3,385 1,001 Contingent purchase price consideration – Quantum 1,911 926 Deferred purchase price consideration – World Energy 1,503 - Accreted contingent compensation to sellers – World Energy 1,000 - Accrued financing fees - 723 Professional fees 940 - Accrued expenses, other 2,614 216 $ 12,954 $ 4,601

ROU Assets and Lease Liabilit_2

ROU Assets and Lease Liabilities (Tables)	9 Months Ended
	Sep. 30, 2021
Regulatory Assets and Liabilities Disclosure [Abstract]
Schedule of office space and R&D and manufacturing facilities	September 30, January 1, December 31, Operating leases: Right-of-use assets $ 3,219 $ 3,481 $ – Lease liability, current 433 469 – Lease liability, non-current 2,841 3,012 – Finance leases: Right-of-use assets 1,252 897 – Lease liability, current 446 265 – Lease liability, non-current 685 632 –
Schedule of other information related to leases	Three Months Ended September 30, Nine Months Ended September 30, 2021 2021 Other information: Operating lease cost $ 222 $ 617 As of 2021 Operating cash flows from operating leases $ 561 Weighted-average remaining lease term – operating leases (in months) 86.8 Weighted-average discount rate – operating leases 9.6 %
Schedule of annual minimum lease payments of our operating lease liabilities	For The Years Ending December 31, 2021 (excluding the nine months ended September 30, 2021) $ 214 2022 673 2023 633 2024 597 2025 613 Thereafter 1,891 Total future minimum lease payments, undiscounted 4,621 Less: imputed interest (1,347 ) Present value of future minimum lease payments $ 3,274

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	9 Months Ended
	Sep. 30, 2021
Fair Value Disclosures [Abstract]
Schedule of fair values private warrants were valued using a black-scholes model	Mark-to-Market Measurement at Mark-to-Market Measurement at September 30, December 31, Input 2021 2020 Risk-free rate 0.81 % 0.36 % Remaining term in years 4.23 4.98 Expected volatility 87.9 % 95.4 % Exercise price $ 11.50 $ 11.50 Fair value of common stock $ 6.16 $ 23.73
Schedule of assets and liabilities which are measured at fair value on a recurring basis	Fair Value Measurements as of Level I Level II Level III Total Asset: Investment in eNow Convertible Note $ - $ - $ 3,000 $ 3,000 Liability:. Private Warrants $ - $ - $ 13,582 $ 13,582 Contingent consideration -– Quantum $ - $ - $ 1,911 $ 1,911 Earnout – World Energy $ - $ - $ 1,000 $ 1,000 Fair value of obligation to issue shares of common stock to sellers of World Energy $ - $ - $ 1,509 $ 1,509 Fair Value Measurements as of Level I Level II Level III Total Liability: Public Warrants $ 62,100 $ - $ - $ 62,100 Private Warrants $ - $ - $ 81,195 $ 81,195 Contingent consideration -– (Quantum) $ - $ - $ 1,849 $ 1,849
Schedule of roll forward of the Company’s Level 3 instruments	As of Asset Liability Balance, January 1, 2021 $ - $ 83,044 Obligation to issue shares of common stock to sellers of World Energy - 1,526 Fair value adjustment – Quantum contingent consideration - 62 Fair value adjustments – Warrant liability - (67,612 ) Fair value adjustments – World Energy - (18 ) Purchase of eNow Convertible Note at fair value 3,000 - Earnout – World Energy - 1,000 Balance, September 30, 2021 $ 3,000 $ 18,002

Warrants (Tables)

Warrants (Tables)	9 Months Ended
	Sep. 30, 2021
Warrants [Abstract]
Schedule of warrant activity	Weighted Average Warrants Shares Exercise Price Outstanding at January 1, 2021 249,117 $ 0.76 Issued - - Exercised (243,000 ) 0.76 Outstanding at September 30, 2021 6,117 $ 0.76 Exercisable at September 30, 2021 6,117 $ 0.76

Share-Based Compensation Expe_2

Share-Based Compensation Expense (Tables)	9 Months Ended
	Sep. 30, 2021
Share-based Payment Arrangement [Abstract]
Schedule of stock option award activity	Options Shares Weighted Weighted Average Outstanding at December 31, 2020 10,975,224 $ 0.57 7.6 Granted 776,116 8.56 Exercised (133,083 ) 0.24 Cancelled or forfeited (559,102 ) 0.65 Outstanding at September 30, 2021 11,059,155 $ 1.01 6.8 Exercisable at September 30, 2021 7,374,132 $ 0.39 6.0
Schedule of fair value of restricted stock awards	Number of Shares Weighted Average Grant Date Fair Value Per Share Non-vested, at beginning of period 446,332 $ 0.24 Granted - - Vested - - Cancelled or forfeited - Non-vested, at end of period 446,332 $ 0.24 Number of Weighted Non-vested, at beginning of period - $ - Granted 476,050 7.08 Vested - - Cancelled or forfeited (4,319 ) 6.49 Non-vested, at end of period 471,731 $ 7.08

Related Party Transactions (Tab

Related Party Transactions (Tables)	9 Months Ended
	Sep. 30, 2021
Related Party Transactions [Abstract]
Schedule of future minimum lease payments	Future minimum lease payments for this lease are as follows: 2021 (Three months) $ 58 2022 39 Total $ 97

Net (Loss) Income Per Share (Ta

Net (Loss) Income Per Share (Tables)	9 Months Ended
	Sep. 30, 2021
Earnings Per Share [Abstract]
Schedule of numerator and denominator used to calculate basic earnings per share and diluted earnings per share	Three Months Ended Nine Months Ended 2021 2020 2021 2020 Numerator: Net (loss) income $ (7,531 ) $ (2,277 ) $ 43,914 $ (22,230 ) Denominator: Weighted average shares outstanding, basic 139,392,170 83,299,127 138,082,355 82,820,099 Dilutive effect of options, warrants, and restricted stock units - - 10,386,753 - Weighted average shares outstanding, diluted 139,392,170 83,299,127 148,469,108 82,820,099 Net (loss) income per share, basic $ (0.05 ) $ (0.03 ) $ 0.32 $ (0.27 ) Net (loss) income per share, diluted $ (0.05 ) $ (0.03 ) $ 0.30 $ (0.27 )
Schedule of number of shares underlying outstanding dilutive securities	Three Months Ended Nine Months Ended 2021 2020 2021 2020 Stock options 11,059,155 10,793,122 173,166 10,793,122 Private Warrants 4,233,333 - 4,233,333 - XL Legacy Warrants 6,117 2,139,593 - 2,139,593 Restricted stock units 471,731 - - - Total 15,770,336 12,932,715 4,406,499 12,932,715

Organization and Description _2

Organization and Description of Business (Details)	May 17, 2021	Sep. 30, 2021
Organization and Description of Business (Details) [Line Items]
Business combination, description		XL Fleet Corp. and its subsidiaries (“XL Fleet” or the “Company”) is a provider of fleet electrification solutions for commercial vehicles in North America, offering solutions for vehicle electrification (“Drive Systems”) and infrastructure solutions such as vehicle charging stations through its XL Grid programs, as further described below. XL Fleet has over 4,400 electrified powertrain systems sold and driven over 173 million miles by over 240 fleets, as of September 30, 2021. XL Fleet’s vision is to become the world leader in commercial fleet electrification solutions, with a mission of accelerating the adoption of fleet electrification systems through cost effective, customer tailored and comprehensive solutions.
World Energy Efficiency Services, LLC [Member]
Organization and Description of Business (Details) [Line Items]
Membership interests, percentage	100.00%

Summary of Significant Accoun_3

Summary of Significant Accounting Policies (Details) $ in Thousands	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021USD ($)	Sep. 30, 2020	Dec. 31, 2020USD ($)
Summary of Significant Accounting Policies (Details) [Line Items]
Cash in excess (in Dollars)			$ 250		$ 250
Restricted cash (in Dollars)			150		150
Allowance of doubtful accounts (in Dollars)			517		0
Inventory reserve for obsolescence (in Dollars)			$ 195		$ 58
Number of operating segment	1		1
Accounts Receivable [Member]
Summary of Significant Accounting Policies (Details) [Line Items]
Number of customers			2		1
Revenue [Member]
Summary of Significant Accounting Policies (Details) [Line Items]
Number of customers	2	2	2	2
Minimum [Member]
Summary of Significant Accounting Policies (Details) [Line Items]
Warrant term			3 years
One customers [Member] | Accounts Receivable [Member]
Summary of Significant Accounting Policies (Details) [Line Items]
Concentration of credit risk, percentage			48.00%		82.00%
Two customers [Member] | Accounts Receivable [Member]
Summary of Significant Accounting Policies (Details) [Line Items]
Concentration of credit risk, percentage			21.00%
Two customers [Member] | Revenue [Member]
Summary of Significant Accounting Policies (Details) [Line Items]
Concentration of credit risk, percentage	80.00%	73.00%	56.00%	69.00%

Summary of Significant Accoun_4

Summary of Significant Accounting Policies (Details) - Schedule of reconciliation of cash, cash equivalents, and restricted cash - USD ($) $ in Thousands	Sep. 30, 2021	Sep. 30, 2020
Cash, cash equivalents, and restricted cash [Abstract]
Cash and cash equivalents	$ 366,748	$ 1,583
Restricted cash	150	150
Total cash, cash equivalents, and restricted cash	$ 366,898	$ 1,733

Summary of Significant Accoun_5

Summary of Significant Accounting Policies (Details) - Schedule of fair value of stock options issued	9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020
Summary of Significant Accounting Policies (Details) - Schedule of fair value of stock options issued [Line Items]
Expected term (in years)	6 years 3 months	6 years 3 months
Expected dividend yield	0.00%	0.00%
Minimum [Member]
Summary of Significant Accounting Policies (Details) - Schedule of fair value of stock options issued [Line Items]
Expected volatility	78.10%	80.00%
Risk-free interest rate	0.40%	0.10%
Maximum [Member]
Summary of Significant Accounting Policies (Details) - Schedule of fair value of stock options issued [Line Items]
Expected volatility	88.20%	80.10%
Risk-free interest rate	1.90%	0.20%

Revenue (Details)

Revenue (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020
Revenue (Details) [Line Items]
Deferred revenue balance	$ 2		$ 2
Description of sales commission			Sales commissions paid to internal sales personnel, as well as associated payroll taxes and retirement plan contributions (together, sales commissions and associated costs) that are incremental to the acquisition of customer contracts, are capitalized as contract acquisition cost on the balance sheet when the period of benefit is determined to be greater than one year. In instances where an extended warranty is sold, the period of benefit would extend beyond 12 months and therefore, the practical expedient would not be met for those contracts and require capitalization of the related costs to obtain those contracts.
Total commission expense	198	$ 13	$ 397	$ 46
Warranty of manufactured products, description			In general, for the sales of Drive Systems, manufactured products are warranted for the shorter of three years or 75,000 miles against defects in material and workmanship when properly used for their intended purpose, installed correctly and appropriately maintained.
Projects warranty term			1 year
Warranty Performance Obligations [Member]
Revenue (Details) [Line Items]
Deferred revenue	$ 239		$ 239		$ 305

Revenue (Details) - Schedule of

Revenue (Details) - Schedule of disaggregation of revenue - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Revenue from the sale of Drive Systems:
Total revenue	$ 3,200	$ 6,328	$ 7,569	$ 9,472
Revenue direct to customers [Member]
Revenue from the sale of Drive Systems:
Total revenue	366	959	1,138	2,020
Revenue through channel partners [Member]
Revenue from the sale of Drive Systems:
Total revenue	189	5,369	1,374	7,452
Revenue from the sale of XL Grid solutions – which are sold direct to customers [Member]
Revenue from the sale of Drive Systems:
Total revenue	$ 2,645		$ 5,057

Revenue (Details) - Schedule _2

Revenue (Details) - Schedule of accrued warranty liability - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2021	Dec. 31, 2020
Schedule of accrued warranty liability [Abstract]
Balance at the beginning of the period	$ 1,735	$ 1,009
Acquisition date accrual for World Energy acquisition	25
Accrual for warranties issued	126	912
Warranty fulfillment charges	(285)	(186)
Balance at the end of the period	$ 1,601	$ 1,735

Business Combination (Details)

Business Combination (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
	Sep. 30, 2021	Sep. 30, 2021	Sep. 30, 2020
Business Combination (Details) [Line Items]
Cash	$ 308	$ 308
Common stock issued shares (in Shares)	448,050	448,050
Aggregate fair value	$ 2,800	$ 2,800
Compensation costs		573
Compensation costs		1,000
Loan amount	507	507
Acquired intangible assets		1,560
Non-recurring merger expenses		498
Interest expense	$ 23	$ 37	$ 64
Business Combination [Member]
Business Combination (Details) [Line Items]
Business combination consideration, Description		The total purchase price consideration, as adjusted, is $12,461 for the acquisition of World Energy. During the three months ended September 30, 2021, the Company remitted to the sellers of World Energy additional cash of $76 in connection with the finalization of working capital adjustments. The as adjusted purchase price consisted of the following components: Cash of $8,496, as adjusted, consisting of the contractual purchase price of $8,000, plus working capital adjustments of an aggregate of $496.  ●The closing date issuance of 231,002 shares of the Company’s common stock, valued at the closing price of $6.23 per share as of May 17, 2021, for a total share fair value upon issuance of $1,439; ●An obligation to issue 244,956 shares of the Company’s common stock to certain of the sellers and their advisors of World Energy, in three equal installments on the sixth, twenty-fourth and the thirtieth monthly anniversaries of the closing date. The closing date fair value was recorded at an aggregate amount of $1,526;  ●An obligation to pay in cash an earnout of $1,000 upon World Energy’s achievement for the calendar year 2021 revenues of $19,500. The payment of the earnout is due within 30 days following the completion of the audit of XL Fleet’s financial statements for the fiscal year ending December 31, 2021. Pursuant to the agreement, the earnout is payable only if revenues for the period equal or exceed $19,500. Should the World Energy revenues be less than $19,500, then the earnout would be $0. The Company determined that the achievement of the $19,500 revenue target was highly probable, and as such, the Company recorded a closing date fair value of the earnout in the amount of $1,000.

Business Combination (Details)

Business Combination (Details) - Schedule of purchase price consideration - Purchase Price Consideration [Member] $ in Thousands	9 Months Ended
	Sep. 30, 2021USD ($)
Condensed Financial Statements, Captions [Line Items]
Cash	$ 8,000
Working capital adjustments	496
Fair value of 231,002 shares issued at closing	1,439
Fair value of the earnout	1,000
Portion of deferred obligation to issue shares of common stock	1,526
Total consideration	12,461
Less the fair value of assets acquired less liabilities assumed	(4,109)
Goodwill	$ 8,352

Business Combination (Details_2

Business Combination (Details) - Schedule of purchase price consideration (Parentheticals)	9 Months Ended
	Sep. 30, 2021shares
Purchase Price Consideration [Member]
Condensed Financial Statements, Captions [Line Items]
Fair value shares issued	231,002

Business Combination (Details_3

Business Combination (Details) - Schedule of fair values of the assets acquired and liabilities assumed by major class - Purchase Price Consideration [Member] $ in Thousands	9 Months Ended
	Sep. 30, 2021USD ($)
Business Combination (Details) - Schedule of fair values of the assets acquired and liabilities assumed by major class [Line Items]
Cash	$ 308
Accounts receivable	3,350
Inventory, net	1,282
Prepaid expenses and other current assets	100
Property and equipment, net	173
Intangible assets, net	1,560
Right-of-use asset	145
Goodwill	8,352
Other assets	12
Accounts payable	(1,096)
Lease liability, current	(56)
Accrued expenses and other current liabilities	(1,297)
Deferred revenue	(283)
Lease liability, non-current	(89)
Total purchase consideration	$ 12,461

Business Combination (Details_4

Business Combination (Details) - Schedule of supplemental disclosure of pro forma information - World Energy [Member] - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended	9 Months Ended
	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Business Combination (Details) - Schedule of supplemental disclosure of pro forma information [Line Items]
Revenues	$ 10,971	$ 15,318	$ 21,003
Net (loss) income	$ (1,630)	$ 44,741	$ (22,194)
Per share amounts: Net (loss) income per share – basic	$ (0.02)	$ 0.32	$ (0.27)
Net loss per share – diluted	$ (0.02)	$ 0.31	$ (0.27)

Purchase of Convertible Note (D

Purchase of Convertible Note (Details) $ in Thousands	Jul. 15, 2021USD ($)
Purchase of Convertible Note [Abstract]
Investment of solar and battery power systems	$ 3,000
Principal amount	$ 3,000
Convertible note bears interest rate	8.00%

Accrued Expenses and Other Cu_3

Accrued Expenses and Other Current Liabilities (Details) - Schedule of accrued expenses and other current liabilities - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2021	Dec. 31, 2020
Schedule of accrued expenses and other current liabilities [Abstract]
Accrued warranty costs	$ 1,601	$ 1,735
Accrued compensation and related benefits	3,385	1,001
Contingent purchase price consideration – Quantum	1,911	926
Deferred purchase price consideration – World Energy	1,503
Accreted contingent compensation to sellers – World Energy	1,000
Accrued financing fees		723
Professional fees	940
Accrued expenses, other	2,614	216
Total	$ 12,954	$ 4,601

ROU Assets and Lease Liabilit_3

ROU Assets and Lease Liabilities (Details) $ in Thousands	Jan. 01, 2021USD ($)
Regulatory Assets and Liabilities Disclosure [Abstract]
Operating lease, right-of-use asset	$ 3,481
Operating lease liabilities	3,481
Finance lease, right-of-use asset	897
Finance lease liabilities	$ 897

ROU Assets and Lease Liabilit_4

ROU Assets and Lease Liabilities (Details) - Schedule of office space and R&D and manufacturing facilities - Office Space and R&D and Manufacturing Facilities [Member] - USD ($) $ in Thousands	Sep. 30, 2021	Jan. 01, 2021	Dec. 31, 2020
Operating leases:
Right-of-use assets	$ 3,219	$ 3,481
Lease liability, current	433	469
Lease liability, non-current	2,841	3,012
Finance leases:
Right-of-use assets	1,252	897
Lease liability, current	446	265
Lease liability, non-current	$ 685	$ 632

ROU Assets and Lease Liabilit_5

ROU Assets and Lease Liabilities (Details) - Schedule of other information related to leases $ in Thousands	3 Months Ended	9 Months Ended
	Sep. 30, 2021USD ($)	Sep. 30, 2021USD ($)
Other information:
Operating lease cost	$ 222	$ 617
Operating cash flows from operating leases		$ 561
Weighted-average remaining lease term – operating leases (in months)	86 years 9 months 18 days	86 years 9 months 18 days
Weighted-average discount rate – operating leases	9.60%	9.60%

ROU Assets and Lease Liabilit_6

ROU Assets and Lease Liabilities (Details) - Schedule of annual minimum lease payments of our operating lease liabilities $ in Thousands	Sep. 30, 2021USD ($)
Schedule of annual minimum lease payments of our operating lease liabilities [Abstract]
2021 (excluding the nine months ended September 30, 2021)	$ 214
2022	673
2023	633
2024	597
2025	613
Thereafter	1,891
Total future minimum lease payments, undiscounted	4,621
Less: imputed interest	(1,347)
Present value of future minimum lease payments	$ 3,274

Note Payable (Details)

Note Payable (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2021USD ($)
PPP Note [Member]
Note Payable (Details) [Line Items]
Principal amount	$ 507

Fair Value Measurements (Detail

Fair Value Measurements (Details) $ / shares in Units, $ in Thousands	9 Months Ended
	Sep. 30, 2021USD ($)$ / sharesshares
Fair Value Measurements (Details) [Line Items]
Public warrants exercised	7,441,020
Warrant price per share (in Dollars per share) | $ / shares	$ 0.01
Warrant [Member]
Fair Value Measurements (Details) [Line Items]
Issuance of shares	7,441,020
Common Stock [Member]
Fair Value Measurements (Details) [Line Items]
Cash proceeds (in Dollars) | $	$ 85,555
Public warrant shares	225,647

Fair Value Measurements (Deta_2

Fair Value Measurements (Details) - Schedule of fair values private warrants were valued using a black-scholes model - $ / shares	9 Months Ended	12 Months Ended
	Sep. 30, 2021	Dec. 31, 2020
Schedule of fair values private warrants were valued using a black-scholes model [Abstract]
Risk-free rate	0.81%	0.36%
Remaining term in years	4 years 2 months 23 days	4 years 11 months 23 days
Expected volatility	87.90%	95.40%
Exercise price	$ 11.5	$ 11.5
Fair value of common stock	$ 6.16	$ 23.73

Fair Value Measurements (Deta_3

Fair Value Measurements (Details) - Schedule of assets and liabilities which are measured at fair value on a recurring basis - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2021	Dec. 31, 2020
Asset:
Investment in eNow Convertible Note	$ 3,000
Liability:.
Public Warrants		$ 62,100
Private Warrants	13,582	81,195
Contingent consideration -– Quantum	1,911	1,849
Earnout – World Energy	1,000
Fair value of obligation to issue shares of common stock to sellers of World Energy	1,509
Level I [Member]
Asset:
Investment in eNow Convertible Note
Liability:.
Public Warrants		62,100
Private Warrants
Contingent consideration -– Quantum
Earnout – World Energy
Fair value of obligation to issue shares of common stock to sellers of World Energy
Level II [Member]
Asset:
Investment in eNow Convertible Note
Liability:.
Public Warrants
Private Warrants
Contingent consideration -– Quantum
Earnout – World Energy
Fair value of obligation to issue shares of common stock to sellers of World Energy
Level III [Member]
Asset:
Investment in eNow Convertible Note	3,000
Liability:.
Public Warrants
Private Warrants	13,582	81,195
Contingent consideration -– Quantum	1,911	$ 1,849
Earnout – World Energy	1,000
Fair value of obligation to issue shares of common stock to sellers of World Energy	$ 1,509

Fair Value Measurements (Deta_4

Fair Value Measurements (Details) - Schedule of roll forward of the Company's Level 3 instruments - Level 3 [Member] $ in Thousands	9 Months Ended
	Sep. 30, 2021USD ($)
Asset [Member]
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning balance
Obligation to issue shares of common stock to sellers of World Energy
Fair value adjustment – Quantum contingent consideration
Fair value adjustments – Warrant liability
Fair value adjustments – World Energy
Purchase of eNow Convertible Note at fair value	3,000
Earnout – World Energy
Ending balance	3,000
Liability [Member]
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning balance	83,044
Obligation to issue shares of common stock to sellers of World Energy	1,526
Fair value adjustment – Quantum contingent consideration	62
Fair value adjustments – Warrant liability	(67,612)
Fair value adjustments – World Energy	(18)
Purchase of eNow Convertible Note at fair value
Earnout – World Energy	1,000
Ending balance	$ 18,002

Warrants (Details)

Warrants (Details)	9 Months Ended
	Sep. 30, 2021
Warrants [Abstract]
Description of warrants	During the nine months ended September 30, 2021, 243,000 Legacy XL Warrants were exercised, which resulted in the issuance of 233,555 shares of the Company’s common stock, in a cashless exercise.

Warrants (Details) - Schedule o

Warrants (Details) - Schedule of warrant activity - Warrant [Member]	9 Months Ended
	Sep. 30, 2021$ / sharesshares
Warrants (Details) - Schedule of warrant activity [Line Items]
Shares, Outstanding, Beginning balance | shares	249,117
Weighted Average Exercise Price, Outstanding, Beginning balance | $ / shares	$ 0.76
Shares, Issued | shares
Weighted Average Exercise Price, Issued | $ / shares
Shares, Exercised | shares	(243,000)
Weighted Average Exercise Price, Exercised | $ / shares	$ 0.76
Shares, Outstanding, Ending balance | shares	6,117
Weighted Average Exercise Price, Outstanding, Ending balance | $ / shares	$ 0.76
Shares, Exercisable, Ending balance | shares	6,117
Weighted Average Exercise Price, Exercisable, Ending balance | $ / shares	$ 0.76

Share-Based Compensation Expe_3

Share-Based Compensation Expense (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Share-Based Compensation Expense (Details) [Line Items]
Share-based compensation expense	$ 1,194	$ 386	$ 2,390	$ 663
Unrecognized compensation cost			$ 9,507
Weighted-average period			3 years 3 months 18 days
Options issued (in Shares)			776,116
Aggregate intrinsic value of stock options outstanding	53,038		$ 53,038
Aggregate intrinsic value of stock options exercisable	$ 38,998		38,998
Cash received from options exercised			$ 32	$ 21
Restricted Stock (in Shares)			476,050
Minimum [Member]
Share-Based Compensation Expense (Details) [Line Items]
Stock options employees and board members term			1 year
Restricted stock units directors term			1 year
Maximum [Member]
Share-Based Compensation Expense (Details) [Line Items]
Stock options employees and board members term			4 years
Restricted stock units directors term			4 years

Share-Based Compensation Expe_4

Share-Based Compensation Expense (Details) - Schedule of stock option award activity	9 Months Ended
	Sep. 30, 2021$ / sharesshares
Schedule of stock option award activity [Abstract]
Shares, Outstanding Beginning balance | shares	10,975,224
Weighted Average Exercise Price, Outstanding Beginning balance | $ / shares	$ 0.57
Weighted Average Remaining Contractual Term, Beginning balance	7 years 7 months 6 days
Shares, Granted | shares	776,116
Weighted Average Exercise Price, Granted | $ / shares	$ 8.56
Shares, Exercised | shares	(133,083)
Weighted Average Exercise Price, Exercised | $ / shares	$ 0.24
Shares, Cancelled or forfeited | shares	(559,102)
Weighted Average Exercise Price, Cancelled or forfeited | $ / shares	$ 0.65
Shares, Ending Balance | shares	11,059,155
Weighted Average Exercise Price, Ending balance | $ / shares	$ 1.01
Weighted Average Remaining Contractual Term, Ending balance	6 years 9 months 18 days
Shares, Exercisable | shares	7,374,132
Weighted Average Exercise Price, Exercisable | $ / shares	$ 0.39
Weighted Average Remaining Contractual Term, Exercisable	6 years

Share-Based Compensation Expe_5

Share-Based Compensation Expense (Details) - Schedule of fair value of restricted stock awards	9 Months Ended
	Sep. 30, 2021$ / sharesshares
Restricted Stock Awards [Member]
Share-Based Compensation Expense (Details) - Schedule of fair value of restricted stock awards [Line Items]
Number of shares, Non-vested, at beginning of period | shares	446,332
Weighted-average grant-date fair value per share, Non-vested, at beginning of period | $ / shares	$ 0.24
Number of shares, Granted | shares
Weighted-average grant-date fair value per share Granted | $ / shares
Number of shares, Vested | shares
Weighted-average grant-date fair value per share, Vested | $ / shares
Number of shares, Cancelled or forfeited | shares
Weighted-average grant-date fair value per share, Cancelled or forfeited | $ / shares
Number of shares, Non-vested, at end of period | shares	446,332
Weighted-average grant-date fair value per share, Non-vested, at end of period | $ / shares	$ 0.24
Restricted Stock Units [Member]
Share-Based Compensation Expense (Details) - Schedule of fair value of restricted stock awards [Line Items]
Number of shares, Non-vested, at beginning of period | shares
Weighted-average grant-date fair value per share, Non-vested, at beginning of period | $ / shares
Number of shares, Granted | shares	476,050
Weighted-average grant-date fair value per share Granted | $ / shares	$ 7.08
Number of shares, Vested | shares
Weighted-average grant-date fair value per share, Vested | $ / shares
Number of shares, Cancelled or forfeited | shares	(4,319)
Weighted-average grant-date fair value per share, Cancelled or forfeited | $ / shares	$ 6.49
Number of shares, Non-vested, at end of period | shares	471,731
Weighted-average grant-date fair value per share, Non-vested, at end of period | $ / shares	$ 7.08

Related Party Transactions (Det

Related Party Transactions (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Related Party Transactions [Abstract]
Rent expense	$ 58	$ 58	$ 173	$ 173

Related Party Transactions (D_2

Related Party Transactions (Details) - Schedule of future minimum lease payments $ in Thousands	Sep. 30, 2021USD ($)
Schedule of future minimum lease payments [Abstract]
2021 (Three months)	$ 58
2022	39
Total	$ 97

Commitments and Contingencies (

Commitments and Contingencies (Details) - USD ($) $ in Thousands	Mar. 02, 2021	Mar. 01, 2021	Mar. 31, 2021	Sep. 30, 2021
Commitments and Contingencies Disclosure [Abstract]
Incurred costs				$ 700
Sponsor fee				$ 500
Sponsor fee paid			$ 250
Purchase price		$ 4,191
Nonrefundable down payment	$ 780
Purchase commitments, description				these purchase obligations consisted of an obligation of $7,800 to purchase batteries by December 2021, an obligation of $2,100 to purchase motors by July 2022 and an open ended commitment of $2,700 to purchase batteries. In light of the lack of OEM chassis availability reducing demand for the Company’s Drive Systems, the Company and the $7,800 battery supplier are negotiating an amendment to this agreement to provide the Company with an additional reasonable period of time to consume the remaining battery commitment.

Net (Loss) Income Per Share (De

Net (Loss) Income Per Share (Details) - Schedule of numerator and denominator used to calculate basic earnings per share and diluted earnings per share - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Numerator:
Net (loss) income	$ (7,531)	$ (2,277)	$ 43,914	$ (22,230)
Denominator:
Weighted average shares outstanding, basic	139,392,170	83,299,127	138,082,355	82,820,099
Dilutive effect of options, warrants, and restricted stock units			$ 10,386,753
Weighted average shares outstanding, diluted	139,392,170	83,299,127	148,469,108	82,820,099
Net (loss) income per share, basic	$ (0.05)	$ (0.03)	$ 0.32	$ (0.27)
Net (loss) income per share, diluted	$ (0.05)	$ (0.03)	$ 0.3	$ (0.27)

Net (Loss) Income Per Share (_2

Net (Loss) Income Per Share (Details) - Schedule of number of shares underlying outstanding dilutive securities - shares	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total	15,770,336	12,932,715	4,406,499	12,932,715
Stock options [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total	11,059,155	10,793,122	173,166	10,793,122
Private Warrants [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total	4,233,333		4,233,333
XL Legacy Warrants [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total	6,117	2,139,593		2,139,593
Restricted stock units [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total	471,731

Retirement Plan (Details)

Retirement Plan (Details)	9 Months Ended
	Sep. 30, 2021
Retirement Plan (Details) [Line Items]
Deferral rate, percentage	3.00%
Retirement plan, description	The Company provides for safe harbor matching contributions equal to 100% on the first 3% of an employee’s eligible earnings deferred and an additional 50% on the next 2% of an employee’s eligible earnings deferred. Employee elective deferrals and safe harbor matching contributions are 100% vested at all times.
Tax-advantaged basis, description	In connection with the acquisition of World Energy, XL Fleet adopted the World Energy 401(k) plan whose features are the same as those of the XL Fleet 401(k) plan except that (i) Participants are allowed to contribute, subject to IRS limitations on total annual contributions from 1% to 100% of eligible earnings and (ii) the safe harbor non-elective contribution is equal to 3% of employee’s compensation.
Minimum [Member]
Retirement Plan (Details) [Line Items]
Annual contributions, percentage	1.00%
Maximum [Member]
Retirement Plan (Details) [Line Items]
Annual contributions, percentage	90.00%

Subsequent Events (Details)

Subsequent Events (Details) - Subsequent Event [Member] - USD ($) $ in Thousands	Nov. 02, 2021	Nov. 01, 2021
Subsequent Events (Details) [Line Items]
Subsequent Event, Description	Hiring of CEO: On November 1, 2021, the Company entered into an executive employment agreement with Eric Tech (the “Employment Agreement”), pursuant to which Mr. Tech will become the Company’s CEO effective December 1, 2021.
Mr. Tech [Member]
Subsequent Events (Details) [Line Items]
Annual base salary		$ 600
Percentage of annual cash bonus on base salary		80.00%
Initial equity grant of stock options value		$ 1,260
Restricted stock units valued		$ 540
Vesting period		4 years