Clean energy hits record share as US solar drives growth

• Clean electricity reached a record 44% share so far in 2025, with solar playing a central role despite policy turbulence and summer demand peaks.

Clean electricity’s footprint in the U.S. keeps widening. Through mid-2025, carbon-free sources supplied a record 44% of generation—up sharply from a decade ago—despite sweltering demand that pushed fossil output and emissions to their yearly highs. Solar’s contribution is central to that shift: daytime supply is flattening peak prices and steadily eroding the mid-afternoon fossil ramp that once defined the grid.

The trend persists even as federal policy has turned less accommodating. Developers have leaned on earlier procurement, tax-credit transfer deals and co-located batteries to keep schedules intact. Batteries matter: they shift noon solar into the critical early-evening hours and provide fast frequency response, which grid operators are now valuing more explicitly. The result is a system that looks less like a rigid daily peak and more like a dynamic portfolio, where storage and flexible loads buffer solar’s variability. 

States are also doing more of the heavy lifting. Several have moved to fast-track permits and contracts so projects can start construction in time to retain credits, offsetting uncertainty at the federal level. Pairing storage with solar is increasingly a prerequisite for interconnection in constrained pockets, which improves project bankability and cuts curtailment risk.

There are challenges: transformer lead times, queue backlogs and evolving rules for projects on federal land. But with clean power’s share setting new marks and pipeline momentum intact, the market signal is strong. Expect a busy fourth quarter as developers chase energization milestones and utilities prepare operating playbooks for another step-change in mid-day solar output next year.