U.S. clean energy job losses accelerated in April to an estimated 447,200, more than tripling from March, as the coronavirus pandemic slammed companies focused on energy efficiency, renewable energy, electric vehicles and other low- to zero-carbon energy solutions, according to BW Research Partnership.

The nearly 600,000 job losses in March and April, detailed in a May 12 memorandum to the American Council on Renewable Energy and other advocacy groups, surpassed the independent research firm's prior estimate that the U.S. clean energy economy could shed half a million jobs by the end of the second quarter.

BW Research now conservatively anticipates that number could hit 850,000 by the end of June, reducing America's clean energy workforce by 25% and adding urgency to industry calls for congressional aid in the form of extended tax credits, cash grants and other incentives.

"While the clean energy industry faced a significant initial drop in March and a staggering tripling of those declines in April, job losses will likely continue to increase," Philip Jordan, vice president of BW Research, said in the memo. Depending on how the crisis unfolds in coming months, clean energy job losses appear on pace to continue growing at a decreasing rate, Jordan added.

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While stay-at-home orders, project permitting delays and public fear of COVID-19 sparked "a glut of unemployment filings among clean energy workers" in April, the impacts on the industry's workforce is worse than the numbers say, according to Jordan.

"Unfortunately, these impacts do not include many temporarily furloughed or underemployed workers," Jordan said.

On a state level, California has sustained, by far, the biggest hit, with more than 105,000 clean energy jobs through April. Mass layoffs have occurred at companies ranging from residential solar installer Horizon Solar Power, Inc., which operates under the Sungevity Inc. brand, to electric car company Tesla Inc. and energy storage and electric bus affiliates of China-based BYD Co. Ltd., according to state unemployment data.

Florida, Michigan and Texas have lost roughly 30,000 jobs each, while the East Coast as a whole has more than twice California's clean energy layoffs. Georgia, Kentucky, Hawaii and Louisiana each saw clean-energy employment fall by more than 20%.

On a sector basis, energy efficiency had the most job losses in April, totaling an estimated 310,200 layoffs, as quarantines kept workers from entering homes and businesses. Renewable power generation lost nearly 72,000 jobs in April, followed by clean vehicles with 35,100.

BW Research's estimates are derived from government and industry data.