"This year the world will make something like 70bn of these solar cells, the vast majority of them in China, and sandwich them between sheets of glass to make what the industry calls modules but most other people call panels: 60 to 72 cells at a time, typically, for most of the modules which end up on residential roofs, more for those destined for commercial plant. Those panels will provide power to family homes, to local electricity collectives, to specific industrial installations and to large electric grids; they will sit unnoticed on roofs, charmingly outside rural schools, controversially across pristine deserts, prosaically on the balconies of blocks of flats and in almost every other setting imaginable.
Once in place they will sit there for decades, making no noise, emitting no fumes, using no resources, costing almost nothing and generating power. It is the least obtrusive revolution imaginable. But it is a revolution nonetheless.
Over the course of 2023 the world’s solar cells, their panels currently covering less than 10,000 square kilometres, produced about 1,600 terawatt-hours of energy (a terawatt, or 1tw, is a trillion watts). That represented about 6% of the electricity generated world wide, and just over 1% of the world’s primary-energy use. That last figure sounds fairly marginal, though rather less so when you consider that the fossil fuels which provide most of the world’s primary energy are much less efficient. More than half the primary energy in coal and oil ends up as waste heat, rather than electricity or forward motion.
What makes solar energy revolutionary is the rate of growth which brought it to this just-beyond-the-marginal state. Michael Liebreich, a veteran analyst of clean-energy technology and economics, puts it this way:
In 2004, it took the world a whole year to install a gigawatt of solar-power capacity...
In 2010, it took a month
In 2016, a week.
In 2023 there were single days which saw a gigawatt of installation worldwide.
Over the course of 2024 analysts at BloombergNEF, a data outfit, expect to see 520-655gw of capacity installed: that’s up to two 2004s a day...
And it shows no signs of stopping, or even slowing down. Buying and installing solar panels is currently the largest single category of investment in electricity generation, according to the International Energy Agency (IEA), an intergovernmental think-tank: it expects $500bn this year, not far short of the sum being put into upstream oil and gas. Installed capacity is doubling every three years. According to the International Solar Energy Society:
Solar power is on track to generate more electricity than all the world’s nuclear power plants in 2026
Than its wind turbines in 2027
Tthan its dams in 2028
Its gas-fired power plants in 2030
And its coal-fired ones in 2032.
In an IEA scenario which provides net-zero carbon-dioxide emissions by the middle of the century, solar energy becomes humankind’s largest source of primary energy—not just electricity—by the 2040s...
Expecting exponentials to carry on is rarely a basis for sober forecasting. At some point either demand or supply faces an unavoidable constraint; a graph which was going up exponentially starts to take on the form of an elongated S. And there is a wide variety of plausible stories about possible constraints...
All real issues. But the past 20 years of solar growth have seen naive extrapolations trounce forecasting soberly informed by such concerns again and again. In 2009, when installed solar capacity worldwide was 23gw, the energy experts at the IEA predicted that in the 20 years to 2030 it would increase to 244gw. It hit that milestone in 2016, when only six of the 20 years had passed. According to Nat Bullard, an energy analyst, over most of the 2010s actual solar installations typically beat the IEA’s five-year forecasts by 235% (see chart). The people who have come closest to predicting what has actually happened have been environmentalists poo-pooed for zealotry and economic illiteracy, such as those at Greenpeace who, also in 2009, predicted 921gw of solar capacity by 2030. Yet even that was an underestimate. The world’s solar capacity hit 1,419gw last year.
-via The Economist, June 20, 2024
Note: That graph. Is fucking ridiculous(ly hopeful).
For perspective: the graph shows that in 2023, there were about 350 GW of solar installed. The 5-year prediction from 2023 said that we'd end up around 450 GW by 2030.
We hit over 600 GW in the first half of 2024 alone.
This is what's called an exponential curve. It's a curve that keeps going up at a rate that gets higher and higher with each year.
This, I firmly believe, is a huge part of what is going to let us save the world.