Spruce Power Holding (SPRU) 10-Q 17 May 21 2021 Q1 Quarterly report Financial data

Document And Entity Information

Document And Entity Information - shares	3 Months Ended
	Mar. 31, 2021	May 13, 2021
Document Information Line Items
Entity Registrant Name	XL Fleet Corp.
Document Type	10-Q
Current Fiscal Year End Date	--12-31
Entity Common Stock, Shares Outstanding		139,126,999
Amendment Flag	false
Entity Central Index Key	0001772720
Entity Current Reporting Status	Yes
Entity Filer Category	Non-accelerated Filer
Document Period End Date	Mar. 31, 2021
Document Fiscal Year Focus	2021
Document Fiscal Period Focus	Q1
Entity Small Business	true
Entity Emerging Growth Company	true
Entity Shell Company	false
Entity Ex Transition Period	false
Document Transition Report	false
Entity File Number	001-38971
Entity Incorporation, State or Country Code	DE
Entity Interactive Data Current	Yes

Unaudited Condensed Consolidate

Unaudited Condensed Consolidated Balance Sheets - USD ($) $ in Thousands		Mar. 31, 2021	Dec. 31, 2020
Current assets:
Cash and cash equivalents		$ 404,132	$ 329,641
Restricted cash		150	150
Accounts receivable		7,572	10,559
Inventory, net		7,196	3,574
Prepaid expenses and other current assets		1,375	1,396
Total current assets		420,425	345,320
Property and equipment, net		1,880	579
Intangible assets, net		448	593
Right-of-use asset		4,224
Goodwill		489	489
Other assets		44	32
Total assets		427,510	347,013
Current liabilities:
Current portion of long-term debt, net of debt discount and issuance costs		88	110
Accounts payable		3,063	4,372
Lease liability, current		757
Accrued expenses and other current liabilities		7,122	4,601
Total current liabilities		11,030	9,083
Long-term debt, net of current portion		80	98
Deferred revenue		305	305
Lease liability, non-current		3,479
Warrant liabilities		23,537	143,295
Contingent consideration			924
New market tax credit obligation	[1]	4,428	4,412
Total liabilities		42,859	158,117
Commitments and contingencies (Note 10)
Stockholders' equity (deficit)
Common stock, $0.0001 par value; 350,000,000 shares authorized at March 31, 2021 and December 31, 2020; 139,105,704 and 131,365,254 issued and outstanding at March 31, 2021 and December 31, 2020, respectively.		14	13
Additional paid-in capital		450,924	317,084
Accumulated deficit		(66,287)	(128,201)
Total stockholders' equity (deficit)		384,651	188,896
Total liabilities and stockholders' equity (deficit)		$ 427,510	$ 347,013
[1]	Held by variable interest entity

Unaudited Condensed Consolida_2

Unaudited Condensed Consolidated Balance Sheets (Parentheticals) - $ / shares	Mar. 31, 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	131,365,254	131,365,254
Common stock, shares outstanding	131,365,254	131,365,254

Unaudited Condensed Consolida_3

Unaudited Condensed Consolidated Statements of Operations - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Income Statement [Abstract]
Revenues	$ 675	$ 1,232
Cost of revenues	1,391	1,284
Gross profit (loss)	(716)	(52)
Operating expenses:
Research and development	1,412	1,014
Selling, general, and administrative expenses	7,958	2,491
Loss from operations	(10,086)	(3,557)
Other (income) expense:
Interest expense, net	11	1,296
Loss on extinguishment of debt		1,038
Change in fair value of warrant liability	(72,005)
Change in fair value of convertible notes payable derivative liability		563
Other income	(6)
Net income (loss)	$ 61,914	$ (6,454)
Net income (loss) per share, basic (in Dollars per share)	$ 0.46	$ (0.08)
Net income (loss) per share, diluted (in Dollars per share)	$ 0.42	$ (0.08)
Weighted-average shares outstanding, basic (in Shares)	135,575,145	82,165,241
Weighted-average shares outstanding, diluted (in Shares)	148,571,379	82,165,241

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
Stock-based compensation expense (in Shares)
Net (loss) income			(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
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
Stock-based compensation expense (in Shares)
Net (loss) income			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

Unaudited Condensed Consolida_5

Unaudited Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Operating activities:
Net income (loss)	$ 61,914	$ (6,454)
Adjustments to reconcile net income (loss) to net cash used in operating activities:
Stock-based compensation	442	52
Bad debt expense	144
Depreciation and amortization expense	219	56
Contingent consideration	14
Fair value change of derivative liability	(72,005)	563
Loss on extinguishment of debt		1,038
Change in operating right-of-use assets	9
Interest on finance leases	3
Debt discount	16	947
Changes in operating assets and liabilities:
Accounts receivable	2,843	220
Inventory, net	(3,622)	(163)
Prepaid expenses and other current assets	21	7
Other assets	(12)	(2)
Accounts payable	(1,309)	(118)
Accrued expenses and other current liabilities	1,361	(657)
Net cash used in operating activities	(9,962)	(4,511)
Investing activities:
Purchases of property and equipment	(1,104)	(94)
Net cash used in investing activities	(1,104)	(94)
Financing activities:
Proceeds from the issuance of subordinated convertible promissory notes		8,100
Repayments of debt	(40)
Repayments under financing leases	(49)
Proceeds from the exercise of warrants		34
Proceeds from recapitalization of PIC shares	75
Proceeds from exercise of stock options	16
Proceeds from exercise of Public Warrants	85,555
Net cash provided by financing activities	85,557	8,134
Net increase in cash and cash equivalents and restricted cash:	74,491	3,529
Cash and cash equivalents and restricted cash, beginning of period	329,791	3,536
Cash, cash equivalents, and restricted cash at end of year	404,282	7,065
Supplemental disclosure of cash flow information:
Cash paid for interest	3	58
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	3 Months Ended
	Mar. 31, 2021
Organization, Description of Business and Liquidity [Abstract]
Organization and Description of Business	Note 1. Organization and Description of Business Description of Business: XL Fleet Corp. and its subsidiaries (“XL Fleet” or the “Company”) is a leading provider of fleet electrification solutions for commercial vehicles in North America, with over 4,300 electrified powertrain systems sold and driven over 150 million miles by over 200 fleets, as of March 31, 2021. XL Fleet’s vision is to become the world leader in fleet electrification solutions, with a mission of accelerating the adoption of fleet electrification systems through cost effective, customer tailored and comprehensive solutions. Merger and Reorganization: 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, the Company initially implemented work from home policies where practical at its facilities in late March 2020. Effective March 31, 2021 all 76 employees have been working full-time from one of the 4 offices or from home. Approximately 30 to 40 employees spend the majority of their work time in one of the company’s offices in Boston, MA, Wixom, MI, Quincy, IL, or Foothill Ranch, CA. The balance of the employees have to date been able to effectively work their jobs remotely from their homes with limited disruptions. Current COVID-19 policies include universal facial covering requirements, rearranging facilities to follow social distancing protocols, employees self-screening before going into the office, enhanced cleaning procedures, and strict quarantine protocols for any suspected or confirmed employee cases. This includes universal facial covering requirements, rearranging facilities to follow social distancing protocols, ensuring employees update the company log to log in upon entering the building, conducting regular temperature checks and undertaking regular and thorough disinfecting of surfaces and tools. 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 March 31, 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	3 Months Ended
	Mar. 31, 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 March 31, 2021, one customer accounted for approximately 80% of accounts receivable. As of December 31, 2020, one customer accounted for approximately 82% of accounts receivable. For the three months ended March 31, 2021 and 2020, three customers and two customers accounted for approximately 79% and 70% of revenues, respectively. Cash and cash equivalents: Restricted cash: Accounts receivable: Inventory: 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 7 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, accounts receivable, accounts payable, accrued liabilities, contingent consideration liability 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. In general, transfer of control is upon shipment of the equipment as the terms are FOB shipping point, or equivalent and 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, the 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 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 as costs to fulfill the promise to transfer the associated equipment and not as a separate performance obligation. The Company provides limited-assurance-type warranties for its equipment and work performed under its 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 this warranty is outside the scope of ASC 606 and will continue to be accounted for under ASC 460, Guarantees. When the Company’s contracts with customers contain multiple performance obligations, 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 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: 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. Compensation cost is typically recognized on a straight-line basis. 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 three months ended March 31, 2021 and 2020 was measured with the following assumptions: Three Months Ended March 31, 2021 2020 Expected volatility 78.1 – 79.9% 80.9% Expected term (in years) 6.25 6.25 Risk-free interest rate 0.4 – 0.5% 1.6% Expected dividend yield 0.0% 0.0% Warrant Liabilities: Research and development expense: Net income (loss) per share: 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	3 Months Ended
	Mar. 31, 2021
Revenue [Abstract]
Revenue	Note 3. Revenue The following table represents the Company’s revenues for the three months ended March 31, 2021 and 2020, respectively, disaggregated, by sales channel. Disaggregation of revenue: March 31, 2021 2020 Revenue direct to customers $ 111 $ 225 Revenue through channel partners 564 1,007 Total revenue $ 675 $ 1,232 Remaining performance obligations: Contract Balances: Costs to obtain a contract: Warranties: The following is a roll-forward of the Company’s accrued warranty liability: As of March 31, December 31, Balance at the beginning of the period $ 1,735 $ 1,009 Accrual for warranties issued 44 912 Warranty charges (82 ) (186 ) Balance at the end of the period $ 1,697 $ 1,735 The warranty liability is included in accrued expenses and other current liabilities on the Unaudited Condensed Consolidated Balance Sheets.

Accrued Expenses and Other Curr

Accrued Expenses and Other Current Liabilities	3 Months Ended
	Mar. 31, 2021
Disclosure Text Block Supplement [Abstract]
Accrued Expenses and Other Current Liabilities	Note 4. Accrued Expenses and Other Current Liabilities Accrued expenses and other current liabilities consisted of the following at March 31, 2021 and December 31, 2020: As of March 31, December 31, Accrued warranty costs $ 1,697 $ 1,735 Accrued compensation and related benefits 1,533 1,001 Contingent purchase price consideration 1,835 926 Accrued financing fees - 723 Accrued expenses, other 2,057 216 $ 7,122 $ 4,601

ROU Assets and Lease Liabilitie

ROU Assets and Lease Liabilities	3 Months Ended
	Mar. 31, 2021
Regulatory Assets and Liabilities Disclosure [Abstract]
ROU Assets and Lease Liabilities	Note 5. 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 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): March 31, January 1, December 31, 2021 2021 2020 Operating leases: Right-of-use assets $ 3,349 $ 3,481 $ – Lease liability, current 465 469 – Lease liability, non-current 2,922 3,012 – Finance leases: Right-of-use assets 875 897 – Lease liability, current 292 265 – Lease liability, non-current 557 632 – Other information related to leases is presented below: Three Months Ended March 31, 2021 Operating lease cost $ 179 Other information: Operating cash flows from operating leases 141 Weighted-average remaining lease term – operating leases (in months) 92.2 Weighted-average discount rate – operating leases 9.6 % As of March 31, 2021, the annual minimum lease payments of our operating lease liabilities were as follows: For The Years Ending March 31, 2021 (excluding the three months ended March 31, 2021) $ 590 2022 606 2023 582 2024 597 2025 613 Thereafter 1,891 Total future minimum lease payments, undiscounted 4,879 Less: imputed interest 1,492 Present value of future minimum lease payments $ 3,387

Fair Value Measurements

Fair Value Measurements	3 Months Ended
	Mar. 31, 2021
Fair Value Disclosures [Abstract]
Fair Value Measurements	Note 6. Fair Value Measurements Mark-to-Market Measurement 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: Input Mark-to-Market Mark-to-Market Risk-free rate 0.84 % 0.36 % Remaining term in years 4.73 4.98 Expected volatility 86.9 % 95.4 % Exercise price $ 11.50 $ 11.50 Fair value of common stock $ 8.98 $ 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 March 31, 2021 Level I Level II Level III Total Liability: Private Warrants $ - $ - $ 23,537 $ 23,537 Contingent consideration $ - $ - $ 1,835 $ 1,835 Fair Value Measurements as of December 31, 2020 Level I Level II Level III Total Liability: Public Warrants $ 62,100 $ - $ - $ 62,100 Private Warrants $ - $ - $ 81,195 $ 81,195 Contingent consideration $ - $ - $ 1,849 $ 1,849 The following is a roll forward of the Company’s Level 3 instruments: Balance, January 1, 2021 $ 145,144 Fair value adjustments- Contingent consideration (14 ) Settlement of derivative liability upon exercise of warrants (47,162 ) Settlement of derivative liability upon call of warrants (591 ) Fair value adjustments- Warrant liability (72,005 ) Balance, March 31, 2021 $ 25,372 During the three months ended March 31, 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.

Warrants

Warrants	3 Months Ended
	Mar. 31, 2021
Warrants [Abstract]
Warrants	Note 7. Warrants Common Stock Warrants: During the three months ended March 31, 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 three months ended March 31, 2021 was as follows: Warrants Shares Weighted Average Outstanding at January 1, 2021 249,117 $ 0.76 Issued - - Exercised (243,000 ) 0.76 Outstanding at March 31, 2021 6,117 $ 0.76 Exercisable at March 31, 2021 6,117 $ 0.76

Share-Based Compensation Expens

Share-Based Compensation Expense	3 Months Ended
	Mar. 31, 2021
Share-based Payment Arrangement [Abstract]
Share-Based Compensation Expense	Note 8. Share-Based Compensation Expense During the three months ended March 31, 2021, the Company issued 185,066 options to certain employees and board members which will vest over a period of one to four years. The weighted-average grant date fair value of stock options awarded during the three months ended March 31, 2021, as determined by the Black-Scholes option pricing model, was $11.98. Share-based compensation expense for the three months ended March 31, 2021 and 2020 was $442 and $51, respectively. As of March 31, 2021, there was $4,777 of unrecognized compensation cost related to share-based payments which is expected to be recognized over the remaining vesting periods, with a weighted-average period of 3.5 years. Stock Options A summary of stock option award activity for the three months ended March 31, 2021 was as follows: Options Shares Weighted Weighted Outstanding at December 31, 2020 10,975,224 $ 0.57 7.6 Granted 185,066 15.12 Exercised (65,875 ) 0.24 Cancelled or forfeited (9,531 ) 4.74 Outstanding at March 31, 2021 11,084,884 $ 0.81 7.4 Exercisable at March 31, 2021 6,026,894 $ 0.26 6.3 The aggregate intrinsic value of stock options exercised in the three months ended March 31, 2021 and 2020 was $1,340 and $0 as determined on the date of exercise. Cash received from options exercised for the three months ended March 31, 2021 and 2020 was $16 and $0, 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 three months ended at March 31, 2021 was as follows: Number of Weighted- 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 three months ended March 31, 2021, the Company issued 35,176 restricted stock units to directors which will vest over a period of one to four years. 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 three months ended at March 31, 2021 was as follows: Number of Weighted- Non-vested, at beginning of period - $ - Granted 35,176 14.17 Vested - - Cancelled or forfeited - - Non-vested, at end of period 35,176 $ 14.17

Related Party Transactions

Related Party Transactions	3 Months Ended
	Mar. 31, 2021
Related Party Transactions [Abstract]
Related Party Transactions	Note 9. Related Party Transactions Operating lease: Rent expense under the operating lease for the three months ended March 31, 2021 and 2020 was $55. Future minimum lease payments for this lease are as follows: 2021 (Nine months) $ 175 2022 39 $ 214

Commitments and Contingencies

Commitments and Contingencies	3 Months Ended
	Mar. 31, 2021
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Note 10. Commitments and Contingencies Sponsorship Commitment: Equipment Purchase: 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 (the “Suh Complaint”). 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 (the “Kumar Complaint”). Both the Suh Complaint and the Kumar Complaint allege 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 Suh Complaint and Kumar Complaint are without merit, and the Company intends to vigorously defend both lawsuits. 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 either lawsuit.

Net Income (Loss) Per Share

Net Income (Loss) Per Share	3 Months Ended
	Mar. 31, 2021
Earnings Per Share [Abstract]
Net Income (Loss) Per Share	Note 11. Net Income (Loss) 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 months ended March 31, 2021, and 2020: Three Months Ended March 31, 2021 2020 Numerator: Net income / (loss) $ 61,914 $ (6,454 ) Denominator: Weighted average shares outstanding, basic 135,575,145 82,165,241 Dilutive effect of options, warrants, and restricted stock units 12,996,234 - Weighted average shares outstanding, diluted 148,571,379 82,165,241 Net income (loss) per share, basic $ 0.46 $ (0.08 ) Net income (loss) per share, diluted $ 0.42 $ (0.08 ) The Company’s contingently issuable unvested restricted stock did not meet the performance based vesting condition as of March 31, 2021 and 2020. 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 March 31, 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 stock options and warrants: As of March 31, 2021 2020 Stock options 11,084,884 11,584,747 Private Warrants 4,233,333 - XL Legacy Warrants 6,117 2,507,338 Restricted stock units 35,176 - Total 15,359,510 14,092,085

Retirement Plan

Retirement Plan	3 Months Ended
	Mar. 31, 2021
Retirement Benefits [Abstract]
Retirement Plan	Note 12. 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.

Subsequent Events

Subsequent Events	3 Months Ended
	Mar. 31, 2021
Subsequent Events [Abstract]
Subsequent Events	Note 13. Subsequent Events Acquisition of World Energy Efficiency Services, LLC On May 17, 2021 (“Closing Date”), the Company acquired 100% of the membership interests of World Energy Efficiency Services, LLC (“World Energy”) for $8.0 million in cash paid on the Closing Date and the obligation to issue shares of the Company’s common stock valued at $7.0 million. The purchase price is subject to an adjustment for closing date net working capital and an additional earn out payment of $1.0 million payable if World Energy achieves its targeted 2021 revenue. With respect to the share component of the purchase price, 231,002 shares were issued at the Closing Date, with the balance issuable in three installments on the 6, 24 and 30 month anniversary of the Closing Date, provided that the senior executives of World Energy remain employed with the Company. World Energy provides turnkey energy efficiency, renewable technology, electric vehicle charging stations and other energy solutions throughout New England. The Company completed the acquisition to further the strategy of its XL Grid business to provide a suite of charging and power solutions to support fleet electrification. Cost of Revenues

Accounting Policies, by Policy

Accounting Policies, by Policy (Policies)	3 Months Ended
	Mar. 31, 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 March 31, 2021, one customer accounted for approximately 80% of accounts receivable. As of December 31, 2020, one customer accounted for approximately 82% of accounts receivable. For the three months ended March 31, 2021 and 2020, three customers and two customers accounted for approximately 79% and 70% of revenues, respectively.
Cash and cash equivalents	Cash and cash equivalents:
Restricted cash	Restricted cash:
Accounts receivable	Accounts receivable:
Inventory	Inventory:
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 7 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, accounts receivable, accounts payable, accrued liabilities, contingent consideration liability 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. In general, transfer of control is upon shipment of the equipment as the terms are FOB shipping point, or equivalent and 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, the 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 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 as costs to fulfill the promise to transfer the associated equipment and not as a separate performance obligation. The Company provides limited-assurance-type warranties for its equipment and work performed under its 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 this warranty is outside the scope of ASC 606 and will continue to be accounted for under ASC 460, Guarantees. When the Company’s contracts with customers contain multiple performance obligations, 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 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:
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. Compensation cost is typically recognized on a straight-line basis. 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 three months ended March 31, 2021 and 2020 was measured with the following assumptions: Three Months Ended March 31, 2021 2020 Expected volatility 78.1 – 79.9% 80.9% Expected term (in years) 6.25 6.25 Risk-free interest rate 0.4 – 0.5% 1.6% Expected dividend yield 0.0% 0.0%
Warrants Liabilities	Warrant Liabilities:
Research and development expense	Research and development expense:
Net loss per share	Net income (loss) per share:
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)	3 Months Ended
	Mar. 31, 2021
Accounting Policies [Abstract]
Schedule of fair value of stock options issued	Three Months Ended March 31, 2021 2020 Expected volatility 78.1 – 79.9% 80.9% Expected term (in years) 6.25 6.25 Risk-free interest rate 0.4 – 0.5% 1.6% Expected dividend yield 0.0% 0.0%

Revenue (Tables)

Revenue (Tables)	3 Months Ended
	Mar. 31, 2021
Revenue from Contract with Customer [Abstract]
Schedule of disaggregation of revenue	March 31, 2021 2020 Revenue direct to customers $ 111 $ 225 Revenue through channel partners 564 1,007 Total revenue $ 675 $ 1,232
Schedule of accrued warranty liability	As of March 31, December 31, Balance at the beginning of the period $ 1,735 $ 1,009 Accrual for warranties issued 44 912 Warranty charges (82 ) (186 ) Balance at the end of the period $ 1,697 $ 1,735

Accrued Expenses and Other Cu_2

Accrued Expenses and Other Current Liabilities (Tables)	3 Months Ended
	Mar. 31, 2021
Disclosure Text Block Supplement [Abstract]
Schedule of accrued expenses and other current liabilities	As of March 31, December 31, Accrued warranty costs $ 1,697 $ 1,735 Accrued compensation and related benefits 1,533 1,001 Contingent purchase price consideration 1,835 926 Accrued financing fees - 723 Accrued expenses, other 2,057 216 $ 7,122 $ 4,601

ROU Assets and Lease Liabilit_2

ROU Assets and Lease Liabilities (Tables)	3 Months Ended
	Mar. 31, 2021
Regulatory Assets and Liabilities Disclosure [Abstract]
Schedule of office space and R&D and manufacturing facilities	March 31, January 1, December 31, 2021 2021 2020 Operating leases: Right-of-use assets $ 3,349 $ 3,481 $ – Lease liability, current 465 469 – Lease liability, non-current 2,922 3,012 – Finance leases: Right-of-use assets 875 897 – Lease liability, current 292 265 – Lease liability, non-current 557 632 –
Schedule of other information related to leases	Three Months Ended March 31, 2021 Operating lease cost $ 179 Other information: Operating cash flows from operating leases 141 Weighted-average remaining lease term – operating leases (in months) 92.2 Weighted-average discount rate – operating leases 9.6 %
Schedule of annual minimum lease payments of our operating lease liabilities	For The Years Ending March 31, 2021 (excluding the three months ended March 31, 2021) $ 590 2022 606 2023 582 2024 597 2025 613 Thereafter 1,891 Total future minimum lease payments, undiscounted 4,879 Less: imputed interest 1,492 Present value of future minimum lease payments $ 3,387

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	3 Months Ended
	Mar. 31, 2021
Fair Value Disclosures [Abstract]
Schedule of fair values private warrants were valued using a black-scholes model	Input Mark-to-Market Mark-to-Market Risk-free rate 0.84 % 0.36 % Remaining term in years 4.73 4.98 Expected volatility 86.9 % 95.4 % Exercise price $ 11.50 $ 11.50 Fair value of common stock $ 8.98 $ 23.73
Schedule of assets and liabilities which are measured at fair value on a recurring basis	Fair Value Measurements as of March 31, 2021 Level I Level II Level III Total Liability: Private Warrants $ - $ - $ 23,537 $ 23,537 Contingent consideration $ - $ - $ 1,835 $ 1,835 Fair Value Measurements as of December 31, 2020 Level I Level II Level III Total Liability: Public Warrants $ 62,100 $ - $ - $ 62,100 Private Warrants $ - $ - $ 81,195 $ 81,195 Contingent consideration $ - $ - $ 1,849 $ 1,849
Schedule of roll forward of the Company’s Level 3 instruments	Balance, January 1, 2021 $ 145,144 Fair value adjustments- Contingent consideration (14 ) Settlement of derivative liability upon exercise of warrants (47,162 ) Settlement of derivative liability upon call of warrants (591 ) Fair value adjustments- Warrant liability (72,005 ) Balance, March 31, 2021 $ 25,372

Warrants (Tables)

Warrants (Tables)	3 Months Ended
	Mar. 31, 2021
Warrants [Abstract]
Schedule of warrant activity	Warrants Shares Weighted Average Outstanding at January 1, 2021 249,117 $ 0.76 Issued - - Exercised (243,000 ) 0.76 Outstanding at March 31, 2021 6,117 $ 0.76 Exercisable at March 31, 2021 6,117 $ 0.76

Share-Based Compensation Expe_2

Share-Based Compensation Expense (Tables)	3 Months Ended
	Mar. 31, 2021
Share-based Payment Arrangement [Abstract]
Schedule of stock option award activity	Options Shares Weighted Weighted Outstanding at December 31, 2020 10,975,224 $ 0.57 7.6 Granted 185,066 15.12 Exercised (65,875 ) 0.24 Cancelled or forfeited (9,531 ) 4.74 Outstanding at March 31, 2021 11,084,884 $ 0.81 7.4 Exercisable at March 31, 2021 6,026,894 $ 0.26 6.3
Schedule of fair value of restricted stock awards	Number of Weighted- 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 35,176 14.17 Vested - - Cancelled or forfeited - - Non-vested, at end of period 35,176 $ 14.17

Related Party Transactions (Tab

Related Party Transactions (Tables)	3 Months Ended
	Mar. 31, 2021
Related Party Transactions [Abstract]
Schedule of future minimum lease payments	2021 (Nine months) $ 175 2022 39 $ 214

Net Income (Loss) Per Share (Ta

Net Income (Loss) Per Share (Tables)	3 Months Ended
	Mar. 31, 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 March 31, 2021 2020 Numerator: Net income / (loss) $ 61,914 $ (6,454 ) Denominator: Weighted average shares outstanding, basic 135,575,145 82,165,241 Dilutive effect of options, warrants, and restricted stock units 12,996,234 - Weighted average shares outstanding, diluted 148,571,379 82,165,241 Net income (loss) per share, basic $ 0.46 $ (0.08 ) Net income (loss) per share, diluted $ 0.42 $ (0.08 )
Schedule of number of shares underlying outstanding stock options and warrants	As of March 31, 2021 2020 Stock options 11,084,884 11,584,747 Private Warrants 4,233,333 - XL Legacy Warrants 6,117 2,507,338 Restricted stock units 35,176 - Total 15,359,510 14,092,085

Organization and Description _2

Organization and Description of Business (Details)	3 Months Ended
	Mar. 31, 2021
Accounting Policies [Abstract]
Business combination, description	and its subsidiaries (“XL Fleet” or the “Company”) is a leading provider of fleet electrification solutions for commercial vehicles in North America, with over 4,300 electrified powertrain systems sold and driven over 150 million miles by over 200 fleets, as of March 31, 2021. XL Fleet’s vision is to become the world leader in fleet electrification solutions, with a mission of accelerating the adoption of fleet electrification systems through cost effective, customer tailored and comprehensive solutions.

Summary of Significant Accoun_3

Summary of Significant Accounting Policies (Details) $ in Thousands	3 Months Ended		12 Months Ended
	Mar. 31, 2021USD ($)	Mar. 31, 2020	Dec. 31, 2020USD ($)
Summary of Significant Accounting Policies (Details) [Line Items]
Cash in excess (in Dollars)	$ 250		$ 250
Allowance of doubtful accounts (in Dollars)	144		0
Inventory reserve for obsolescence (in Dollars)	$ 215		$ 58
Warrant term	3 years
Accounts Receivable [Member]
Summary of Significant Accounting Policies (Details) [Line Items]
Number of customers	1		1
Concentration of credit risk, percentage	80.00%		82.00%
Revenue [Member]
Summary of Significant Accounting Policies (Details) [Line Items]
Number of customers	3	2
Concentration of credit risk, percentage	79.00%	70.00%

Summary of Significant Accoun_4

Summary of Significant Accounting Policies (Details) - Schedule of fair value of stock options issued	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Summary of Significant Accounting Policies (Details) - Schedule of fair value of stock options issued [Line Items]
Expected volatility		80.90%
Expected term (in years)	6 years 3 months	6 years 3 months
Risk-free interest rate		1.60%
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%
Risk-free interest rate	0.40%
Maximum [Member]
Summary of Significant Accounting Policies (Details) - Schedule of fair value of stock options issued [Line Items]
Expected volatility	79.90%
Risk-free interest rate	0.50%

Revenue (Details)

Revenue (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Revenue (Details) [Line Items]
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 capitalized 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	$ 256	$ 15
Warranty of manufactured products, description	In general, manufactured products are warranted for the shorter of three years or 100,000 miles against defects in material and workmanship when properly used for their intended purpose, installed correctly and appropriately maintained.
Warranty Performance Obligations [Member]
Revenue (Details) [Line Items]
Deferred revenue	$ 305

Revenue (Details) - Schedule of

Revenue (Details) - Schedule of disaggregation of revenue - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Revenue direct to customers [Member]
Revenue (Details) - Schedule of disaggregation of revenue [Line Items]
Total revenue	$ 111	$ 225
Revenue through channel partners [Member]
Revenue (Details) - Schedule of disaggregation of revenue [Line Items]
Total revenue	564	1,007
Total Revenue [Member]
Revenue (Details) - Schedule of disaggregation of revenue [Line Items]
Total revenue	$ 675	$ 1,232

Revenue (Details) - Schedule _2

Revenue (Details) - Schedule of accrued warranty liability - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2021	Dec. 31, 2020
Schedule of accrued warranty liability [Abstract]
Balance at the beginning of the period	$ 1,735	$ 1,009
Accrual for warranties issued	44	912
Warranty charges	(82)	(186)
Balance at the end of the period	$ 1,697	$ 1,735

Accrued Expenses and Other Cu_3

Accrued Expenses and Other Current Liabilities (Details) - Schedule of accrued expenses and other current liabilities - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Schedule of accrued expenses and other current liabilities [Abstract]
Accrued warranty costs	$ 1,697	$ 1,735
Accrued compensation and related benefits	1,533	1,001
Contingent purchase price consideration	1,835	926
Accrued financing fees		723
Accrued expenses, other	2,057	216
Total	$ 7,122	$ 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	Mar. 31, 2021	Jan. 01, 2021	Dec. 31, 2020
Operating leases:
Right-of-use assets	$ 3,349	$ 3,481
Lease liability, current	465	469
Lease liability, non-current	2,922	3,012
Finance leases:
Right-of-use assets	875	897
Lease liability, current	292	265
Lease liability, non-current	$ 557	$ 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
	Mar. 31, 2021USD ($)
Schedule of other information related to leases [Abstract]
Operating lease cost	$ 179
Other information:
Operating cash flows from operating leases	$ 141
Weighted-average remaining lease term – operating leases (in months)	92 months 6 days
Weighted-average discount rate – operating leases	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	Mar. 31, 2021USD ($)
Schedule of annual minimum lease payments of our operating lease liabilities [Abstract]
2021 (excluding the three months ended March 31, 2021)	$ 590
2022	606
2023	582
2024	597
2025	613
Thereafter	1,891
Total future minimum lease payments, undiscounted	4,879
Less: imputed interest	1,492
Present value of future minimum lease payments	$ 3,387

Fair Value Measurements (Detail

Fair Value Measurements (Details) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2021USD ($)$ / sharesshares
Fair Value Measurements (Details) [Line Items]
Waarrant exercised	7,441,020
Public warrant shares	225,647
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]
Issuance of public warrant (in Dollars) | $	$ 85,555

Fair Value Measurements (Deta_2

Fair Value Measurements (Details) - Schedule of fair values private warrants were valued using a black-scholes model - $ / shares	3 Months Ended	12 Months Ended
	Mar. 31, 2021	Dec. 31, 2020
Schedule of fair values private warrants were valued using a black-scholes model [Abstract]
Risk-free rate	0.84%	0.36%
Remaining term in years	4 years 266 days	4 years 357 days
Expected volatility	86.90%	95.40%
Exercise price	$ 11.50	$ 11.50
Fair value of common stock	$ 8.98	$ 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	3 Months Ended	12 Months Ended
	Mar. 31, 2021	Dec. 31, 2020
Liability:
Public Warrants		$ 62,100
Private Warrants	$ 23,537	81,195
Contingent consideration	1,835	1,849
Level I [Member]
Liability:
Public Warrants		62,100
Private Warrants
Contingent consideration
Level II [Member]
Liability:
Public Warrants
Private Warrants
Contingent consideration
Level III [Member]
Liability:
Public Warrants
Private Warrants	23,537	81,195
Contingent consideration	$ 1,835	$ 1,849

Fair Value Measurements (Deta_4

Fair Value Measurements (Details) - Schedule of roll forward of the Company’s Level 3 instruments $ in Thousands	3 Months Ended
	Mar. 31, 2021USD ($)
Schedule of roll forward of the Company’s Level 3 instruments [Abstract]
Balance	$ 145,144
Fair value adjustments- Contingent consideration	(14)
Settlement of derivative liability upon exercise of warrants	(47,162)
Settlement of derivative liability upon call of warrants	(591)
Fair value adjustments- Warrant liability	(72,005)
Balance	$ 25,372

Warrants (Details)

Warrants (Details)	3 Months Ended
	Mar. 31, 2021
Warrants [Abstract]
Description of warrants	During the three months ended March 31, 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]	3 Months Ended
	Mar. 31, 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 ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Share-Based Compensation Expense (Details) [Line Items]
Options issued (in Shares)	185,066
Weighted-average grant date fair value (in Dollars per share)	$ 11.98
Share-based compensation expense	$ 442	$ 51
Unrecognized compensation cost	$ 4,777
Weighted-average period	3 years 6 months
Aggregate intrinsic value	$ 1,340	0
Cash received from options exercised	$ 16	$ 0
Restricted Stock (in Shares)	35,176
Minimum [Member]
Share-Based Compensation Expense (Details) [Line Items]
Vesting period	1 year
Maximum [Member]
Share-Based Compensation Expense (Details) [Line Items]
Vesting period	4 years

Share-Based Compensation Expe_4

Share-Based Compensation Expense (Details) - Schedule of stock option award activity	3 Months Ended
	Mar. 31, 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 219 days
Shares, Granted | shares	185,066
Weighted Average Exercise Price, Granted | $ / shares	$ 15.12
Shares, Exercised | shares	(65,875)
Weighted Average Exercise Price, Exercised | $ / shares	$ 0.24
Shares, Cancelled or forfeited | shares	(9,531)
Weighted Average Exercise Price, Cancelled or forfeited | $ / shares	$ 4.74
Shares, Ending Balance | shares	11,084,884
Weighted Average Exercise Price, Ending balance | $ / shares	$ 0.81
Weighted Average Remaining Contractual Term, Ending balance	7 years 146 days
Shares, Exercisable | shares	6,026,894
Weighted Average Exercise Price, Exercisable | $ / shares	$ 0.26
Weighted Average Remaining Contractual Term, Exercisable	6 years 109 days

Share-Based Compensation Expe_5

Share-Based Compensation Expense (Details) - Schedule of fair value of restricted stock awards	3 Months Ended
	Mar. 31, 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	35,176
Weighted-average grant-date fair value per share Granted | $ / shares	$ 14.17
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	35,176
Weighted-average grant-date fair value per share, Non-vested, at end of period | $ / shares	$ 14.17

Related Party Transactions (Det

Related Party Transactions (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2021USD ($)
Related Party Transactions [Abstract]
Rent expenses	$ 55

Related Party Transactions (D_2

Related Party Transactions (Details) - Schedule of future minimum lease payments $ in Thousands	Mar. 31, 2021USD ($)
Schedule of future minimum lease payments [Abstract]
2021	$ 175
2022	39
Total	$ 214

Commitments and Contingencies (

Commitments and Contingencies (Details) - USD ($)	Mar. 01, 2021	Feb. 24, 2021
Commitments and Contingencies Disclosure [Abstract]
Sponsor fees		$ 500
Purchase value	$ 4,100
Total of purchase price	$ 800

Net Income (Loss) Per Share (De

Net Income (Loss) 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
	Mar. 31, 2021	Mar. 31, 2020
Numerator:
Net income / (loss)	$ 61,914	$ (6,454)
Denominator:
Weighted average shares outstanding, basic	135,575,145	82,165,241
Dilutive effect of options, warrants, and restricted stock units	$ 12,996,234
Weighted average shares outstanding, basic and diluted	148,571,379	82,165,241
Net income (loss) per share, basic	$ 0.46	$ (0.08)
Net income (loss) per share, basic and diluted	$ 0.42	$ (0.08)

Net Income (Loss) Per Share (_2

Net Income (Loss) Per Share (Details) - Schedule of number of shares underlying outstanding stock options and warrants - shares	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total	15,359,510	14,092,085
Stock options [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total	11,084,884	11,584,747
Private Warrants [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total	4,233,333
XL Legacy Warrants [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total	6,117	2,507,338
Restricted stock units [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total	35,176

Retirement Plan (Details)

Retirement Plan (Details)	3 Months Ended
	Mar. 31, 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.
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] $ in Millions	1 Months Ended
	May 17, 2021USD ($)shares
Subsequent Events (Details) [Line Items]
Cash value	$ 8
Stock value	7
Other payable	$ 1
Purchase price, shares (in Shares) | shares	231,002
World Energy Efficiency Services, LLC (“World Energy”) [Member]
Subsequent Events (Details) [Line Items]
Membership interest	100.00%