Solar Stocks Surge as Trump Administration Eases Clean Energy Tax Credit Rules

Shares of U.S. solar energy companies rallied Monday after the Trump administration issued new guidance on clean energy tax credits that proved less restrictive than investors had feared. The Treasury Department on Friday clarified rules for determining when a solar or wind project is considered “under construction,” a key requirement to qualify for federal tax credits covering up to 30% of project costs. The revised rules require developers to complete some physical construction work rather than simply demonstrate capital investment. While solar companies initially criticized the shift, analysts and investors welcomed the outcome as far more favorable than expected. The MAC Global Solar Energy Index rose 4% in mid-day trading, with Sunrun shares up 9% and First Solar gaining 8.6%. Concerns had centered on whether developers would face higher upfront costs or tighter deadlines to secure subsidies. Instead, the Treasury preserved the existing four-year window for projects to finish construction after starting. Under the One Big Beautiful Bill Act, projects must break ground by July 2026 or be operational by the end of 2027 to qualify. Analysts noted that while the changes introduce some complexity, they keep the incentives largely intact, offering relief to clean energy investors.