As the year comes to a close, we’re looking back at the top stories from Solar Power World in 2025.
SPW readers were eager to learn more about the One Big Beautiful Bill Act’s (OBBBA) evolving implications for the solar industry, as well as the major company bankruptcies and layoffs that were often attributed to the new law. It wasn’t all doom and gloom, though. Some of the most popular stories detailed new technologies, like residential energy storage innovations and solar module developments.
Below, you’ll find the 10 most-read stories of 2025. To stay on top of all the news in U.S. solar going into 2026, subscribe to our free newsletter, the Daily Solar Scoop.
10. New Treasury guidance requires large-scale solar projects to use ‘physical work test’ for ITC safe harbor
In August, the Dept. of the Treasury released new guidance related to safe harboring solar projects under the ITC. The guidance requires projects larger than 1.5 MW to use the “physical work test” in order to secure ITC safe harbor, along with some other new specifications.
9. Solar finance platform Mosaic files for bankruptcy
Over the summer, residential solar and home improvement financing platform Mosaic announced it filed for Chapter 11 bankruptcy protection in the Southern District of Texas. Mosaic blamed “macroeconomic challenges” for impacting its access to capital.
8. What does “safe harboring” mean for the solar industry?
Safe harboring allows companies to demonstrate a good-faith effort at starting a solar project to lock in the applicable tax credits in place that year. With changing OBBBA rules, securing any credits possible before the phase-down is crucial.
7 . SolarEdge rolls out stackable residential LFP battery at RE+
SolarEdge showcased its new residential solar+storage product called Nexis at RE+ 2025. The platform’s DC-optimized technology provides more backup hours and a quick, simple installation.
6. Pine Gate Renewables files for bankruptcy, selling solar business and project portfolio
National solar developer Pine Gate Renewables announced it was filing for Chapter 11 bankruptcy in November. The company plans to sell both its solar and energy storage project portfolio and independent power producer business, including completed and under-development projects.
5. Draft budget kills residential ITC, preserves large-scale and manufacturing credits
Multiple iterations of the OBBBA kept the industry up at night in the first half of 2025. Find all of Solar Power World’s coverage of the new law here.
4. Commerce reveals final tariff amounts on Southeast Asian solar imports
The ongoing AD/CVD investigation on Southeast Asian solar imports finally came to a conclusion this year after the U.S. International Trade Commission made an affirmative determination in the case. The final tariff amounts ranged from 14.64% for Hanwha Qcells imports to 3,521.14% for Hounen Solar panels.
3. Residential solar installer PosiGen lays off almost entire workforce
National residential solar installation company PosiGen laid off nearly all of its employees in August. PosiGen CEO Peter Shaper sent a memo addressed to all employees attributing the layoffs to lack of funding from the OBBBA.
2. EcoFlow launches energy storage system that doesn’t require utility approval
EcoFlow rolled out a new plug-and-play solar + storage system for the U.S. residential market, starting in Utah where this setup is currently allowed. This “balcony solar” option that’s prevalent in Europe does not require utility approval in select markets.
1. While China scales high-efficiency solar panel manufacturing, the US is stuck with PERC
While Asian brands continue to grow their n-type solar panel output, American brands are stalled out with their p-type designs. Editor-in-chief Kelly Pickerel’s deep dive into this tech conundrum was the top story of 2025.
See you in 2026 🎉
