08What gets built, and how fast?
How much of the year each fleet runs
How hard does each kind of power plant work across a year, compared with what it could deliver?
In 2025, Germany's solar fleet produced as much as it would running at full output for 10% of the year, and its wind fleet 20%, taking the year's generation against the fleet at the year's end (Ember).
On the same measure, the world's solar fleet reached 13% in 2025.
A lower bound: the year-end fleet counts capacity that ran for only part of the year.
Why a fleet's size and its output are two different numbers
Installed capacity says what a fleet could produce, and the capacity factor says what it did produce: the year's generation divided by what the fleet would produce running flat out all year. It is the number that turns a headline about gigawatts into electricity. A gigawatt of solar in Germany delivers roughly a tenth of a gigawatt averaged over the year, because the sun is down half the time and low in winter; a gigawatt of nuclear delivers most of a gigawatt while the plants run; a gigawatt of gas delivers whatever the market pays it to, which in Germany has been under a third.
Beyond the technology, two things move the figure. The first is the resource: the same panel runs a larger share of the year in Spain than in Germany, and an offshore turbine a larger share than one inland. The second is the role: a gas plant that runs only when wind and solar fall short has a low capacity factor by design, and the number says nothing about whether it is a good plant.
The figure here is a lower bound, and the reason is in the denominator. The fleet is counted at the year's end, so a country that adds a fifth of its solar in a year is dividing a full year's output by a fleet that only existed in full on the last day. The faster the build-out, the larger the understatement; for a fleet that is not growing the bias disappears. Ember's figures come from national statistics, so a country that defines capacity and generation differently carries that into the ratio. No figure is shown for a fleet under a tenth of a gigawatt, where rounding alone would swing it.
The comparison at the bottom holds solar and wind for the world and four large economies in the latest year. The pattern follows geography: India's solar fleet runs a larger share of the year than Germany's because of where it is, and the world figure sits between them because the fleet is spread across both kinds of place. The rest of the difference is the year-end bias, which is largest exactly where the fleet grew most.
How these numbers are made: Implied capacity factor.