Solar Stocks Rise on Treasury Department Safe Harbor Guidance

By Nicholas G. Miller

Shares of solar companies rose Monday, continuing a surge from Friday, after the Treasury Department issued new rules about which solar and wind projects could continue to receive tax credits.

Shares of SunRun were up 9% after rising 33% Friday. SolarEdge shares were up 2.6% Monday after surging 17% Friday. First Solar was up 9% after an 11% increase on Friday. Enphase stock was up 3.7% after rising 8.1% on Friday.

The safe harbor guidance, which President Trump directed the Treasury Department to issue in an executive order last month, was friendlier to the renewable energy industry than analysts had expected.

President Trump's tax bill signed last month placed an early end to multiple tax credits subsidizing the cost of renewable energy projects. But safe harbor rules allow for projects to continue receiving the tax credits in perpetuity if they begin and finish construction before a certain date.

The newly issued rules focused on the thresholds renewable energy projects have to meet to classify as having begun. Many in the industry expected the guidance to significantly increase the spending required to count as starting a project, which would have made it largely impossible for some companies to secure the tax credits.

Instead, the new rules preserved the current threshold for some kinds of projects, including for residential solar projects, which companies like Enphase and SunRun rely upon. For utility projects, which First Solar focuses on, the rules established a physical work test, which relies on the physical work performed rather than the money spent, to determine if a project has begun.

Write to Nicholas G. Miller at nicholas.miller@wsj.com.

(END) Dow Jones Newswires

August 18, 2025 13:10 ET (17:10 GMT)