Why don’t we just do solar instead of nuclear?

First, Fukushima is not as bad as you may think. Specifically, no-one died or is projected to die due to radiation released at Fukushima.

Second, we want less CO₂ to be produced in the production of our electricity needs, we need to move away from fossil fuels. The nuclear advocates and the solar advocates usually agree on this. The problem is that nuclear fills a niche that solar really struggles with: base load. I went hunting for the most recent information on the South African situation, and I came across this presentation which shows the problem with South African power quite clearly – there are large peaks in usage in the morning and the afternoon in winter. This Eskom infographic has a nicer display of the winter and summer behaviour. I also tried to find good information on the insolation in SA and ended up choosing a weather station in the Richtersveldt for my data since it is located in a nice open area in the best solar position in the country. When you plot these together, you get this graph:

Notice how the peaks take place at times where there isn’t really much sun. This means solar power can’t really supply the power for those peaks directly. More importantly, it can’t help with the minimum demand at 02:00. We would have to store the energy somehow.

Another issue often bandied about in these conversations is how expensive the nuclear plants would be. The figures I’ve heard are that the nuclear deal is perhaps going to cost around R1.2T for 9.6 GW of nuclear nameplate capacity. People look at that and think “if Solar PV costs around $3/W, we could build the same solar capacity for a fraction of the price”.  The problem, of course, is that the capacity factors for the two technologies aren’t the same. For nuclear they’re around 90%, while for solar they’re around 20 %. This means we would need to install around 43 GW of nameplate capacity solar to produce the same amount of electricity, which costs more than R1.2T just by itself at $3/W. Then we would have to pay for the storage and the refitting of our grid to allow for the distributed generation which the solar plants would inevitably represent. I love solar, but we’re not at the point where it can do the base load generation we would be purchasing with nuclear.