Exhibit 99.1

XL Fleet Announces Fourth Quarter and Full-Year 2021 Financial Results

BOSTON, March 1, 2022 – XL Fleet Corp. (NYSE: XL) (“XL Fleet” or the “Company”), a leading provider of fleet electrification solutions, today announced fourth quarter and full-year 2021 financial results.

Fourth Quarter, Full-Year 2021 and Recent Highlights

Management Commentary & Outlook

“XL Fleet continued to diversify its solutions portfolio in 2021, most notably with the May acquisition of World Energy Efficiency Services, which helped to offset demand and supply chain issues continuing to face the drivetrain business,” said Eric Tech, CEO of XL Fleet. “World Energy generated $7.7 million of revenue for the fourth quarter of 2021 and over $20 million for the full-year 2021, which was ahead of the forecast set at the time of the acquisition. We exited the year with $352 million in cash on the balance sheet, positioning us offensively and defensively in the road ahead.”

“Since joining XL Fleet, I have taken a comprehensive review of all aspects of our business to assess the offerings, strategy, and growth opportunities,” added Mr. Tech. “While our Strategic Review remains ongoing, I have identified several near-term opportunities and actions that align our talent, technology and resources, while best positioning XL Fleet over the long-term.”

“First, we will focus on organizing our leadership and talent in a way that maximizes synergies across our business,” continued Mr. Tech. “Second, we will narrow focus of our hybrid offering to platforms and applications that are most scalable and provide the most substantial return on investment. And third, we will continue to preserve our strong cash position, with an intent on identifying transformational M&A that enhances shareholder value while setting the state for long-term growth resulting from the global needs for decarbonization. I am invigorated by the work that remains ahead, and stand confident in XL Fleet’s ability to leverage its platform, experience and resources to help drive decarbonization for the benefit of all.”

Fourth Quarter 2021 Financial Results

Revenue totaled $8.0 million in the fourth quarter of 2021 compared to $3.2 million in the third quarter of 2021 and $10.9 million in the fourth quarter of 2020. Revenue from the sale of drive systems in the fourth quarter of 2021 totaled $0.3 million compared with $0.6 million in the third quarter of 2021, and $10.9 million in the fourth quarter of 2020, due to negative impacts from ongoing supply chain issues including microchip shortages that have led to a lack of new fleet chassis. Revenue from XL Grid in the fourth quarter of 2021 totaled $7.7 million, compared to $2.6 million in the third quarter of 2021 and $6.4 million in the fourth quarter of 2020 on a pro forma basis. The increase from the third quarter of 2021 was due to the seasonality of the business driven by sales cycles and other dynamics in the business.

Gross loss was $1.6 million for the fourth quarter of 2021, compared to a gross profit of $0.7 million in the third quarter of 2021 and gross profit of $2.0 million in the fourth quarter of 2020. Gross margins for the fourth quarter of 2021 were negative (20%), compared to gross margins for the third quarter of 2021 of positive 22%. The decrease in gross margins was primarily driven by increased inventory reserves. Adjusted EBITDA was ($14.6) million for the fourth quarter of 2021, compared to ($14.2) million for the third quarter of 2021 and ($1.8) million in the fourth quarter of 2020.

Net loss was ($15.1) million for the fourth quarter of 2021, compared to net loss of ($7.5) million in the third quarter of 2021 and ($38.4) million in the fourth quarter of 2020. Net loss for the fourth quarter of 2021 includes a non-cash gain from the change in fair value of warrant liability of $8.2 million, compared to a non-cash loss of ($35.0) million in the fourth quarter of 2020. Adjusted net loss was $15.3 million for the fourth quarter of 2021, compared to adjusted net loss of ($14.7) million in the third quarter of 2021. A reconciliation of net (loss) income to adjusted EBITDA and net (loss) income to adjusted net loss is below.

Full-Year 2021 Financial Results

Revenue totaled $15.6 million for full-year 2021, compared to $20.3 million for full-year 2020. Gross loss totaled ($0.7) million for full-year 2021, compared to a gross profit of $2.7 million for the full-year 2020. Adjusted EBITDA for full-year 2021 totaled ($50.0) million, compared to ($14.7) million for the full-year 2020.

Balance Sheet and Capital

Cash and cash equivalents as of December 31, 2021 totaled $351.7 million compared to $329.6 million as of December 31, 2020. Total debt outstanding as of December 31, 2021 was approximately $0.1 million. XL Fleet has approximately 140.5 million shares of Common Stock outstanding as of December 31, 2021.

Fourth Quarter 2021 and Recent Operational & Business Updates

Conference Call Information

The XL Fleet management team will host a conference call to discuss its fourth quarter 2021 financial results today at 5:00 p.m. Eastern Time. The call can be accessed live over the telephone by dialing 877-407-3982, or for international callers, 201-493-6780 and referencing XL Fleet. Alternatively, the call can be accessed via a live webcast accessible on the Events & Presentations page in the Investor Relations section of the Company’s website at www.xlfleet.com. A replay will be available shortly after the call and can be accessed by dialing 844-512-2921, or for international callers, 412-317-6671. The passcode for the replay is 13726640. The replay will be available until March 15, 2022. An archive of the webcast will be available for a period of time shortly after the call on the Investor Relations section of The Company’s website at www.xlfleet.com.

About XL Fleet

XL Fleet is a leading provider of vehicle electrification solutions for commercial and municipal fleets in North America, with more than 180 million miles driven by customers such as The Coca-Cola Company, Verizon, Yale University and the City of Boston. XL Fleet’s hybrid and plug-in hybrid electric drive systems can significantly increase fuel economy and reduce carbon dioxide emissions, decreasing operating costs and meeting sustainability goals while enhancing fleet operations. For additional information, please visit www.xlfleet.com.

Forward Looking Statements

Certain statements in this press release may constitute “forward-looking statements” within the meaning of the federal securities laws. Forward-looking statements generally are accompanied by words such as “believe,” “may,” “will,” “estimate,” “continue,” “anticipate,” “intend,” “expect,” “should,” “would,” “plan,” “predict,” “potential,” “seem,” “seek,” “future,” “outlook,” and similar expressions that predict or indicate future events or trends or that are not statements of historical matters. These statements are based on various assumptions, whether or not identified in this press release, and on the current expectations of management and are not predictions of actual performance. Forward-looking statements are subject to a number of risks and uncertainties that could cause actual results to differ materially from the forward-looking statements, including but not limited to; the effects of pending and future legislation; the highly competitive nature of the Company’s business and the commercial vehicle electrification market; litigation, complaints, product liability claims and/or adverse publicity; cost increases or shortages in the components or chassis necessary to support the Company’s products and services; the introduction of new technologies; the impact of the COVID-19 pandemic on the Company’s business, results of operations, financial condition, regulatory compliance and customer experience; the potential loss of certain significant customers; privacy and data protection laws, privacy or data breaches, or the loss of data; general economic, financial, legal, political and business conditions and changes in domestic and foreign markets; the inability to convert its sales opportunity pipeline into binding orders; risks related to the rollout of the Company’s business and the timing of expected business milestones, including the ongoing global microchip shortage and limited availability of chassis from vehicle OEMs and our reliance on our suppliers; the effects of competition on the Company’s future business; the availability of capital; changes in the preliminary financial results for the quarter ended September 30, 2021 upon completion of the Company’s financial closing procedures or upon review and completion of procedures by the Company’s independent registered public accounting firm, and the other risks discussed under the heading “Risk Factors” in the Company’s annual report on Form 10-K filed on March 1, 2022, and other documents that the Company files with the SEC in the future. If any of these risks materialize or our assumptions prove incorrect, actual results could differ materially from the results implied by these forward-looking statements. These forward-looking statements speak only as of the date hereof and the Company specifically disclaims any obligation to update these forward-looking statements.

Use of Non-GAAP Financial Information

To supplement its consolidated financial statements, which are prepared and presented in accordance with U.S. generally accepted accounting principles (“GAAP”), XL Fleet Corp. reports EBITDA, Adjusted EBITDA, and Adjusted Net Income (Loss) which are non-GAAP financial measures. EBITDA is determined by taking net income and adding interest, depreciation and amortization. Adjusted EBITDA is determined by taking EBITDA and adding change in fair value of obligation to issue shares of common stock to sellers of World Energy, non-recurring World Energy acquisition expenses and accreted contingent compensation obligation to sellers of World Energy, change in fair value of warrant liability, change in fair value of convertible notes payable derivative liabilities and loss on extinguishment of debt. Adjusted Net Income (Loss) is determined by taking Net Income (Loss) and adding change in fair value of obligation to issue shares of common stock to sellers of World Energy, non-recurring World Energy acquisition expenses, accreted contingent compensation obligation to sellers of World Energy, change in fair value of warrant liability, and change in fair value of convertible notes payable derivative liabilities and loss on extinguishment of debt. This prospective financial information was not prepared with a view toward compliance with published guidelines of the SEC or the guidelines established by the American Institute of Certified Public Accountants for preparation and presentation of prospective financial information or U.S. GAAP with respect to forward looking financial information. We believe that these non-GAAP measures, viewed in addition to and not in lieu of our reported GAAP results, provides useful information to investors by providing a more focused measure of operating results, enhances the overall understanding of past financial performance and future prospects, and allows for greater transparency with respect to key metrics used by management in its financial and operational decision making. The non-GAAP measures presented herein may not be comparable to similarly titled measures presented by other companies. EBITDA, Adjusted EBITDA and Adjusted Net Income (Loss) have been reconciled to the nearest GAAP measures in the tables within these this press release.

Investor Contact:

xlfleetIR@icrinc.com

Media Contact:

PR@xlfleet.com

XL Fleet Corp.

Audited Consolidated Statements of Operations

For the Three and Twelve Months Ended December 31, 2021 and December 31, 2020

XL Fleet Corp.

Reconciliation of Non-GAAP Financial Measures

For the Three and Twelve Months Ended December 31, 2021 and December 31, 2020

XL Fleet Corp.

Audited Condensed Consolidated Balance Sheets

As of December 31, 2021 and December 31, 2020

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