The world crossed the global solar capacity milestone of 3 terawatts in early 2026, completing the third terawatt in just 19 months, a pace that has repeatedly outrun the projections of analysts and policymakers alike. Getting to the first terawatt took nearly 68 years. The second arrived in roughly two years.
How fast is fast? The numbers behind the global solar capacity milestone
The rate of deployment is now high enough that even well-resourced research bodies are publishing competing tallies. Ember‘s Global Electricity Review puts new solar installations in 2025 at 647 GW, an 11% increase on 2024. The underlying trajectory is the same either way: solar is being built faster than at any point in history, and the compounding is accelerating.
In the first quarter of 2026, solar and battery storage together accounted for 91% of all new grid capacity added in the United States. That figure captures something broader than a technology preference: it reflects where costs have landed after years of price compression driven largely by Chinese manufacturers, who now account for more than half of all solar installations worldwide.
Wind and solar crossed another threshold in April 2026, generating more electricity globally than natural gas for the first time. According to Ember, the two sources together produced a record 531 TWh that month, against 477 TWh from gas, a gap of 54 TWh. Wind and solar combined now supply around 22% of global electricity; gas sits at 20%.
From wealthy nations to a 74-country technology
The first terawatt was built almost entirely in wealthy countries, underwritten by subsidies that lower-income nations could not replicate. The second and third terawatts have a different geography. The number of countries with at least 1 GW of installed solar has grown to 74, up from 42 in 2020. Solar now supplies roughly 9% of the world’s electricity, up from 3% in 2020.
Some of the fastest growth is happening in countries with the most pressing energy problems. Pakistan, Nigeria, the Philippines, and Cuba have all seen large increases in rooftop solar, with households buying panels to escape rising fossil fuel costs. Panel prices have fallen far enough that solar is viable in markets that could not have justified the investment a decade ago.
China’s role in driving that price collapse comes with its own complications. Solar deployment in China has outpaced transmission infrastructure and battery storage, leading to curtailment during peak hours when generation exceeds what the grid can absorb. China’s latest Five-Year Plan targets more than a 50% increase in renewables consumption by 2030, shifting the emphasis from building capacity to actually using it.
Storage: the constraint that determines the ceiling
The global solar capacity milestone at 3 terawatts is, in part, a manufacturing and installation story. What comes next is a different kind of problem. ‘Without enough energy storage, you cannot maximise solar’s potential,’ said Lara Hayim, head of solar research at BloombergNEF. Countries where solar has moved fastest, including Pakistan and the Philippines, are already seeing parallel surges in battery installations.
BloombergNEF forecasts more than 9 terawatts of installed solar by 2036, three times the current total. Given that the third terawatt arrived 19 months after the second, that figure may prove conservative. The storage gap is, by most accounts, the variable that will determine whether the forecast holds or gets beaten again.
