Wind power now exceeds nuclear

The global installed capacity of wind power now exceeds nuclear, and solar is not far behind. These technologies have very different capacity factors, so nuclear is still ahead in terms of actual electricity produced. However, we can see where the trends are going, and nuclear is getting its ass kicked.

The saturated colours show installed capacity, and the pastel colours show actual production. Dotted lines show industry forecasts for installed capacity. The difference between capacity and production is the capacity factor. No generating technology is ever capable of running at 100% power all the time. Solar panels can't produce at night, and wind turbines can't produce when there's no wind, Nuclear has the highest capacity factor, with individual reactors able to run at 100% for up to a couple of years, but sooner or later they have to shut down for lengthy maintenance, repairs, and fuel replacement. Over the long term, the global nuclear fleet has an average capacity factor of only 75%. Wind is typically around 30%, and solar is 10%. That's why the pastel blue (nuclear), green (wind), and red (solar) lines are below the saturated blue, green and red.

Note that capacity is typically given in units of GW, while production is in units of TWh, but these are really both units of power when you realize that production on an annual basis. Here's the conversion:

• 1 GW X 365 days/year X 24 hours/day X 0.001 T/G = 8.76 TWh/year
• 100 GW = 876 TWh/year

Although this graph shows current trends, that does not necessarily reflect the true relative merits of the technologies. These trends may be biased by current political perceptions and might not continue in the long term. A key challenge to wind an solar is their intermittency and the lack of cost effective electricity storage. There is some potential for consumers to adapt by using electricity when it is available, but we will still have a need to run refrigerators and streetlights on windless nights. Nuclear power has the opposite problem that it has to run at near 100% all the time, and has limited capacity to follow the rise and fall of actual variable demand. You can vent steam to avoid overvolting the grid, but that doesn't save any fuel or money. If you shut down a reactor, you can't bring it back up for three days because of xenon poisoning. That's just long enough so that you can't shut down a reactor for the weekend, otherwise you won't have enough power available on Monday morning.

Load following is done by throttling fossil fuel plants in most jurisdictions. In a climate-constrained future, we are going to need new ways of doing this, and none of the three options here can offer a complete solution.

I built this graph myself by combining data from several source:

1. IAEA Power Reactor Information System (PRIS)
2. US Energy Information Administration, International Energy Statistics
3. Global Wind Energy Council, Global Wind Statistics
4. European Photovoltaic Industry Association, Global Market Outlook
5. Renewables 2016 Global Status Report