Originally published December 11, 2013. Updated September 18, 2026.
Solar was the biggest source of new power on the US grid for the fifth year running in 2025, with 43 gigawatts of new capacity installed, even though that total was 14% below 2024. Installs picked back up in 2026. The US added 11.4 GW in the second quarter alone, up 45% from a year earlier. Worldwide, solar grew faster still. Global installations hit 647 GW in 2025, and solar generation jumped 30% in a single year, the fastest growth rate in eight years. That’s about to slow in one country. A new law ended the tax credit for home solar systems in late 2025, and Wood Mackenzie now expects US solar to grow up to 18% slower over five years than it forecast before.
How much solar the US installed in 2025 and 2026
The 43 GW the US installed in 2025 made solar the single biggest source of new generating capacity on the grid for the fifth year running, according to SEIA and Wood Mackenzie’s market report. Add battery storage to solar and the two together made up 70% of everything the US built in the first half of 2026, with solar alone accounting for 45%. In the first quarter of 2026, solar and storage combined were an even bigger share, 91% of all new US power capacity.
Quarter over quarter, the pace kept climbing. The US installed 7.8 GW of solar in the first quarter of 2026, then 11.4 GW in the second quarter, a jump of 43% from the first quarter and 45% from the same quarter a year earlier.
Further out, the growth curve levels off. SEIA and Wood Mackenzie now expect the US to add 217 GWdc of solar between 2026 and 2031, an average of about 44 GWdc a year, a pace the report itself calls flat even as the country’s total solar fleet nearly doubles over that stretch.
How much of America’s electricity comes from solar now
Installed capacity and the electricity a panel produces are two different numbers, and understanding capacity factor is what connects them. The current figures on both sides of that gap are large. The EIA estimates utility-scale solar alone supplied about 9.6% of all US electricity generation in 2025, up 34% from 2024. Add rooftop solar and wind, and wind and solar combined made up 19% of total US electricity generation in 2025.
The US had 123 GW of total installed solar capacity in 2024, rising to 151 GW in 2025, with the EIA projecting 181 GW by the end of 2026. The agency expects solar generation to keep climbing too, forecasting growth of 21% in 2026 and another 18% in 2027. Utility-scale solar projects made up more than half of the 64 GW of new US generating capacity planned for 2025, with the rest split across other sources.
How the 2025 tax law is reshaping the outlook
A new tax law is now the biggest threat to that pace. The One Big Beautiful Bill Act, signed in July 2025, ended the 30% federal tax credit for residential solar systems as of December 31, 2025, and tightened the rules for the commercial and utility credits that remain. Those projects now have to begin construction by July 4, 2026, or be in service by the end of 2027 to qualify.
Wood Mackenzie has put a number on what that means. In its base case, the firm now expects 246 GWdc of US solar to be added between 2025 and 2030, 4% (11 GWdc) less than it projected before the law passed. Its downside scenario is steeper, with as much as 18% (44 GWdc) less, and 2026 and 2027 alone landing about 30% below the firm’s base case. Residential solar is taking the direct hit. Wood Mackenzie forecasts US residential solar installations falling 21% in 2026 compared with the year before.
For a sense of how forecasts like this move over time, the International Energy Agency publishes its own yearly solar projections, which is worth checking alongside Wood Mackenzie’s numbers.
How fast the rest of the world is installing solar
Global solar installations set a record in 2025. The world added 647 GW of solar capacity in 2025, up 11% from 582 GW in 2024. Solar generation grew even faster. Global output reached 2,778 TWh in 2025, up from 2,143 TWh in 2024, a jump of 30%, the fastest growth rate in eight years, and that same year solar overtook wind generation worldwide for the first time.
Solar alone met 75% of the entire increase in global electricity demand in 2025. Its share of the world’s total electricity mix is climbing fast too. Solar supplied 8.8% of global electricity in the first half of 2025, up from 6.9% a year earlier and 3.8% in the first half of 2021, more than doubling in four years.
A solar module cost $2.51 per watt in 2010, in today’s dollars, and fell to $0.265 per watt by 2024, a decline of about 89%. That drop hasn’t leveled off. In 2023, the global weighted-average cost of electricity from solar PV fell 12% year over year, the steepest decline among major renewable sources that IRENA tracks.
Which country has the most solar power
China installed 256 GW of new solar in the first half of 2025 alone, more than the rest of the world combined (124 GW) out of a 380 GW global total. By the end of 2025, China’s cumulative installed solar capacity reached 1.20 terawatts, up 35.4% from the year before.
| Country / region | Installed solar capacity | As of |
|---|---|---|
| China | 1.20 TW (1,200 GW) | End of 2025 |
| United States | 151 GW | End of 2025 |
| World total | 1,865 GW | End of 2024 |
Source: China figure from National Energy Administration data, via pv magazine. United States figure from EIA, Short-Term Energy Outlook, September 2026. World total from IRENA, Renewables in 2024.
Comparing these numbers exactly is harder than it looks. The world row is a year older than the China and US rows above it, dating to before the record global additions of 2025 described above. China’s own energy agency also counts installations in AC terms, while global trackers like Ember use DC ratings for the same projects.
What would change this outlook
A 2013 analysis by Elias Hinckley, a strategic advisor on energy finance and energy policy, asked whether the US solar boom was about to get much bigger. At the time, solar supplied only 0.2% of US electricity generation, and fewer than 250,000 US homes had a system installed. Module prices had already fallen, in the dollars of the time, from $1.81 per watt in 2010 to under $0.70 per watt by the time he wrote. Hinckley figured that at an installed cost of $3 per watt, the US could support roughly 100 GW of solar with no subsidy at all, and he expected a rough patch before growth turned explosive.
That rough patch came and went, and the boom did get bigger. Utility-scale solar generation grew 34% in 2025 alone, and the country now has 151 GW installed, on track for 181 GW by the end of 2026.
The next rough patch has a different cause than the one Hinckley expected. A specific law, the One Big Beautiful Bill Act, cut off the residential tax credit and reset the rules for commercial and utility projects, and Wood Mackenzie’s own forecast is what to watch next. SEIA and Wood Mackenzie’s market outlook still has the US adding 217 GWdc of solar by 2031, a pace the report itself calls flat even as the fleet nearly doubles. If growth undershoots toward the firm’s downside case instead, that’s the number worth watching. Wood Mackenzie has already tied its lower forecast directly to the new tax law.
