| Per Ember Energy reports, a cost optimal new build grid is between 90% - 97% solar/wind/battery, and between 3% to 10% gas peaker depending on how much sun/wind your locale gets. But you can't replace the gas peaker with 3% or 10% nuclear because in essence that gas peaker is supplying 100% of the power 3% to 10% of the time. So you'd have to build nuclear plants that can supply 100% of the power. But once you have that you might as well use nuclear power 100% of the time because the rest is irrelevant. But that's about as far from cost-optimal as you can get. As you mentioned, using batteries for seasonal storage is madness. So to get to 100% carbon free you have at least 2 other options: 1. use a different form of seasonal storage. China is experimenting with this. In 2026 they will double the world's pumped hydro storage capacity. But doubling isn't a lot -- the world doesn't have much pumped hydro. But it does mean they might start doing it at China scale in a few years. 2. Overbuild to avoid the need for seasonal storage. Solar works on cloudy days and in the winter. It just doesn't work very well. So you need a lot of it. Which is expensive, but still a heck of a lot cheaper than batteries for seasonal storage. In reality, most places will probably say that 95% or 99% carbon reduction is good enough and keep their backup natural gas generators around for the occasional dankelflaute. |
There is not a single analysis out there that tackles the twin problems of meeting growing electricity demand with a power source that depends on an uncertain and changing climate.
You say "occasional" dunkelflaute, but we have no idea whether occasional is once a season or once a decade.
This is exactly where nuclear shines, because although it is expensive, it insulates a country against the vagaries of external forces. Whether or not that guarantee is worth the price tag is the question a lot of governments are grappling with and they mostly seem to agree that the value is indeed worth the cost.