Global solar capacity passes 3 TW as grids face the next test

The world has just crossed a line that once belonged to specialists: 3 TW of installed solar capacity. The exact date depends on the database and methodology, but the direction is unmistakable. Solar has moved from a niche technology to one of the main ways the world adds power capacity.

The pace tells the story. BloombergNEF estimates that global solar capacity took about 10 years to rise from 100 GW in 2012 to 1 TW. The second terawatt was added in less than three years; the third arrived less than two years later. BloombergNEF expects the total to exceed 9 TW by 2036, putting today’s milestone inside a much larger expansion already under way.

China supplied much of the momentum. It paired fast installation with large-scale manufacturing, helping reduce technology costs and spread solar to other markets. Pakistan, Nigeria and the Philippines have seen strong growth, particularly in rooftop systems. Smaller markets, including Cuba and Lebanon, have also expanded quickly. The number of countries with at least 1 GW of installed solar capacity reached 74 in 2025, compared with 42 in 2020.

But panels are only one part of a power system. In China, solar deployment has grown faster than the infrastructure needed to move and store the electricity, leading to more curtailment — power generation reduced when the grid cannot absorb it. A slowdown in new Chinese installations is expected as the country turns toward grid integration and the capacity needed to consume more renewable electricity.

So what changes, concretely? The next phase will be measured less by how many panels are installed than by how much of their electricity can be used. Lithium-ion batteries can absorb excess solar at peak production and release it later, including after sunset. Transmission and flexible demand will matter too. BloombergNEF identifies storage as decisive: without enough of it, adding solar capacity will make it increasingly difficult to use all the electricity that panels can produce.