Solar remained the largest engine of new US power capacity in 2025
Utility-scale solar continued to dominate new power additions to the US grid in 2025, according to Federal Energy Regulatory Commission data cited by PV Magazine. Developers installed 26,556 megawatts of new utility-scale solar capacity over the year, accounting for the large majority of 36,551 megawatts in total new generating capacity.
The headline is not merely that solar grew. It is that solar remained the central driver of grid expansion even after a slight year-over-year dip from the 33.8 gigawatts installed in 2024. In other words, the market cooled modestly from a very high level, but not enough to alter the basic shape of new US generation growth.
Solar now represents 12.16% of total available installed generating capacity in the United States, according to the source text. That is a meaningful marker. Capacity share and annual additions are not the same thing, but taken together they show that solar is no longer a marginal build-out story. It is a structural part of how the grid is expanding.
Renewables supplied nearly 90% of utility-scale additions
The broader renewable picture is similarly clear. Solar and wind together accounted for nearly 90% of all new utility-scale generating capacity added through December 2025. That concentration matters because it shows where developers, utilities, and investors are still finding the strongest deployment momentum.
The supplied data also show how year-end additions were distributed. In December alone, developers brought 1,193 megawatts of new capacity online. Seventeen solar units accounted for 993 megawatts of that total, while a single wind project contributed another 200 megawatts. Even in a single month snapshot, solar was the dominant source of newly energized capacity.
Several utility-scale projects illustrate the scale of what is being built. Among the notable December completions were the 325 megawatt Iron Pine Solar Project in Pine County, Minnesota, and the 201.1 megawatt Morrow Lake Solar & Storage Project in Frio County, Texas. Those project names matter because they show that the build-out is geographically diverse and increasingly linked to storage.
Growth, but with signs of a more mature market
The slight decline from 2024 should not be mistaken for a reversal. A market can remain dominant while still shifting from one record year to a somewhat smaller one. What the 2025 numbers suggest is a sector moving deeper into a scale phase, where the more important question is not whether solar is growing, but how it is integrating into the broader power system.
That is where the combination of annual additions and installed-capacity share becomes useful. Solar is not only winning a large share of new builds. It is steadily increasing its role in the existing generation mix. Over time, that changes grid planning, interconnection priorities, transmission needs, and the economics of storage and flexible generation.
The Morrow Lake project, specifically described as solar plus storage, hints at that next phase. Storage does not change the fact that solar output varies with sunlight, but pairing capacity this way can make renewable additions more useful to grid operators and more valuable to project owners. The article does not provide a wider storage total, but even the example signals the direction of travel.
Why these figures matter
FERC capacity data do not answer every question about electricity generation, reliability, or curtailment. Capacity is not the same as actual output. But capacity additions remain one of the clearest ways to see what the US power sector is choosing to build. On that measure, the signal is strong: utility-scale renewables, and especially solar, continue to dominate.
That matters for several reasons. First, it suggests the economics and policy environment still support large-scale deployment. Second, it indicates that new grid investment is increasingly shaped by technologies with different operating patterns than conventional fossil generation. Third, it reinforces the idea that the US energy transition is no longer only about future ambition; it is visible in annual infrastructure totals.
The 2025 results therefore read less like a one-off surge and more like continued system change. Solar did not match its 2024 total, but it remained the backbone of new US capacity growth. Until another technology starts posting comparable annual additions, that remains the central fact of the market.
This article is based on reporting by PV Magazine. Read the original article.
