Solar crosses 3 TW threshold

Global solar power capacity has passed 3 trillion watts (terawatts, or TW) of installed capacity, according to BloombergNEF. The growth curve keeps steepening: it took about 10 years to go from 100 gigawatts in 2012 to 1 TW, less than three years to add the second TW, and under two years for the third. Analysts expect this pace to keep climbing, with global capacity projected to top 9 TW by 2036.

China has driven most of this recent growth, pairing massive solar deployment with manufacturing scale that has pushed panel costs down worldwide. But solar is also spreading into markets that barely registered a few years ago, including Pakistan, Nigeria, the Philippines, Cuba, and Lebanon, often through rooftop installations. The number of countries with at least 1 gigawatt of solar capacity has grown from 42 in 2020 to 74 now. Even so, deployment is still concentrated in a handful of big markets, and BNEF expects that to start shifting after 2026, with developing countries eventually reaching more than a quarter of global installed capacity.

None of this changes what a home solar system costs or qualifies for today, but it points to where the industry is headed: less about just adding panels, more about storage and grid capacity. China is already seeing curtailment, where solar output gets throttled back because the grid and batteries can't absorb it all. Lithium-ion battery storage, which stores excess solar power to use later, including after dark, is becoming a bigger part of the equation. For a homeowner weighing panels, that suggests battery storage will matter more, not less, over time.