And it shows no signs of slowing down. Buying and installing solar panels is currently the largest category of investment in electricity generation, according to the International Energy Agency (IEA), with $500 billion expected to be invested in 2024, not far behind the amount spent on oil and gas. Installed capacity is doubling every three years. According to the International Solar Energy Society, solar power will generate more electricity than all the world’s nuclear power plants by 2026, surpass wind turbines in 2027, hydroelectric dams in 2028, gas-fired power plants in 2030, and coal-fired power plants in 2032. Under an IEA scenario of net-zero CO2 emissions by mid-century, solar power will become the world’s largest primary energy source by 2040.
Solar’s growth isn’t just a function of efforts to combat climate change. If it continues to get cheaper, it will grow even if coal and oil are still in use. In a study published in 2022, Rupert Way of the buy phone number list University of Oxford and his colleagues attempted to predict what would happen if the costs of solar and other innovative technologies continued to decline as usage increased. In their “rapid transition” scenario, they found that by 2070, the world could get more useful energy from solar cells than it did from all energy sources combined last year.
Expecting exponential growth to continue indefinitely is not a solid basis for forecasting, however. At some point, both supply and demand hit inevitable limits, turning an exponential growth graph into an S-curve. There are many potential obstacles: failing producers, off-grid solar farms, unstable grids powered predominantly by solar, or grids so saturated with solar that they no longer attract investment.
But over the past 20 years, solar growth has consistently outpaced conservative forecasts. In 2009, when the world’s installed solar capacity was 23 GW, the IEA predicted it would reach 244 GW by 2030. That mark was reached in 2016, in just six years. During much of the 2010s, solar installations exceeded the IEA’s five-year forecast by 235%, according to Nat Bullard. Even forecasts from environmental groups, often criticized for overoptimism, have been modest: Greenpeace estimated 921 GW of solar capacity by 2030, but the world already surpassed 1,400 GW last year.