Solar supplied three-quarters of the growth in global electricity demand in 2025, but it hadn’t quite overtaken nuclear over the full year. Ember’s annual electricity data show the two nearly level. A separate BBC analysis reports that solar pulled ahead during the Northern Hemisphere summer.
The distinction matters: annual generation, summer output and rolling 12-month totals aren’t interchangeable. Drawing on Ember’s monthly data, the BBC puts solar generation 13% above nuclear over the 12 months before September 2026. It also projects that solar’s share of global electricity generation will reach 10% this year, up from roughly 1% a decade earlier. These are electricity figures, not shares of all energy consumed worldwide.
China’s enormous manufacturing capacity and rising oil prices help explain the expansion. The BBC traces it through seven connected developments, from cheaper panels to the grid upgrades needed to use their output.
Table of Contents
1. An underestimated force
“Solar power is currently the engine of the energy transition,” says Jan Rosenow, professor of energy and climate policy at the University of Oxford.
According to the BBC, solar has become the fastest-growing new electricity source in history and, by a wide margin, the largest source of new electricity generation worldwide. Wind generation is growing too, but more slowly.
Rosenow argues that mainstream forecasts repeatedly underestimated solar. Even reports from the International Energy Agency, or IEA, “assumed linear growth and slowly declining costs, but were wrong about both.” Forecasters didn’t just underestimate how many panels would be installed. They also missed how quickly the economics would change.
Since 2000, nuclear generation has remained more or less steady, while solar generation has increased roughly 2,700-fold, according to the BBC. That helps explain how solar caught up with a technology that had a decades-long head start. It doesn’t mean solar is the world’s largest electricity source overall: this milestone concerns its position relative to nuclear.
2. Extremely cheap panels
In 2020, the IEA described solar as providing the cheapest electricity in history. Deployment and efficiency have continued to rise since then. Manufacturers have also reduced the amounts of silicon and silver used in panels, pushing prices lower still.
“China’s enormous manufacturing scale and current overcapacity have pushed prices to record lows,” Rosenow says.
Prices fell particularly sharply in 2023-24. The BBC puts the current price of an individual panel well below $100, giving 32,000 Hungarian forints as a comparison. It describes panels as capable of generating electricity for 30-40 years without further expenditure. That claim concerns the panel itself, not the full cost of installing and operating a solar system.
Alongside the economic argument are climate and health benefits. Cheaper electricity is one part of the case; reducing the effects of fossil-fuel use is another.
3. Deployment beyond China
China remains by far the world’s largest solar electricity producer. But the expansion isn’t confined to China: the United States still ranks second for installations, and deployment there continues to climb sharply.
US solar capacity can now generate enough electricity to supply the equivalent of more than one-third of American households. That measures generation capacity; it doesn’t mean those homes run exclusively on solar around the clock.
Alicia Zhao, a University of Maryland specialist in US emissions reductions, explains the tension between policy and price: “Tariffs and other policies that restrict renewable energy growth increase costs and slow deployment compared with what it would otherwise be. But economics is a key factor in why solar has grown so quickly. Despite rising costs, solar remains one of the cheapest new energy sources in the United States. And it is being built regardless of political direction.”
Her assessment is consistent with the analysis of renewable growth despite federal policy uncertainty cited by the BBC. Policy can slow construction without removing the financial reason to build.
The BBC also describes India as moving away from fossil fuels faster than China on this measure: new solar installations covered 60% of the increase in electricity demand over the past two years. In Australia, more than four million homes have rooftop solar systems, representing well over one-third of households.
4. Unreliable fossil-fuel supply
Pakistan and Lebanon have been installing solar at a rapid pace. Across Africa, the BBC reports that roughly 100,000 panels are installed every day.
In many places, fuel-price increases linked to the Russia-Ukraine conflict and conditions in the Middle East have tipped the cost calculation toward solar. That difference is especially tangible in African countries where unreliable grids leave households dependent on diesel generators. Panels offer an alternative to repeatedly buying fuel to keep the lights on.
Solar can also add electricity supply quickly where fossil-fuel-based grids aren’t keeping up with demand. Pakistan’s solar expansion is a striking example: solar met less than 2% of the country’s electricity needs in 2019, compared with 24% in the BBC’s current account.
Much of that growth has come from purchases by ordinary people, rather than solely from large, centrally planned projects. The BBC identifies similar patterns in other sunny countries, including Lebanon and Nigeria.
5. The battery shift
Pairing solar with batteries makes its electricity available beyond the hours when panels are producing it. Falling battery costs and support schemes are making those combinations easier to deploy.
California provides a concrete example. During the first half of 2026, solar and batteries together covered, on average, more than one-quarter of electricity demand during the evening peak between 7 p.m. and 9 p.m., according to the BBC.
Vermont is introducing home battery systems integrated with the grid, often paired with solar panels. This connects household equipment to the wider electricity system rather than treating each battery as an isolated backup box.
Long-duration storage remains a limitation, the BBC notes. Batteries help shift solar output into the evening, but storing energy for much longer periods is a separate challenge. Grid integration matters alongside the batteries themselves.
6. Electrify everything
Solar’s role extends beyond replacing one electricity generator with another. Electrification can reduce fossil-fuel use in activities that previously didn’t run on electricity, with electric cars as a clear example.
The BBC identifies electrification as one of the main themes selected for the 2026 UN climate conference in Turkey. The wider ambition is to use more electricity for tasks that currently require directly burning fuel.
“Solar is on its way to becoming not just the king of electricity, but the king of energy,” says Dave Jones, identified by the BBC as a co-founder of the Ember think tank.
Getting there requires deliberate planning. Adding generating capacity without continuing to improve the network can leave grids vulnerable. In Rosenow’s assessment, grids and storage, rather than panels themselves, now set the limits on solar expansion.
In the United States, data centers and electric cars are helping push electricity demand upward after decades of relatively flat demand. That makes the ability to deliver power, not merely generate it, a strategic issue. The BBC connects this concern to the US government’s declaration of a national energy emergency.
7. More ways to install solar
In Germany, plug-in balcony solar panels have spread rapidly in recent years. They produce less electricity than rooftop systems, but feed it directly into a home through a standard electrical socket.
These systems are now permitted in numerous other countries and some US states. They allow installations beyond the conventional rooftop setup, though their lower output remains an important distinction.
Other technologies that could expand in the coming years include floating solar farms, mirror-based solar installations, perovskite panels and solar windows. These are potential avenues for growth, not approaches already being deployed at comparable scale.
What comes next?
Global solar capacity is expected to keep increasing in 2026, but the rate of expansion could slow for the first time in a long while. The main reason is China.
China changed its arrangements for managing and supporting new solar installations in summer 2025. A large share of that year’s installations consequently came under the old pricing system, complicating comparisons with subsequent deployment.
Outside China, the picture is different: the BBC expects more panels to be installed in 2026 than in 2025. A slowdown in the largest market doesn’t mean installations are retreating everywhere.
“Where grid electricity is expensive and unreliable, people will continue to turn to solar,” Rosenow says. “But there is a caveat: if importing Chinese solar panels is difficult, that can slow the process.”
