Is the decline of nuclear destroying the progress of renewables?

Insights from the IEA World Energy Investment 2016 report.

4 minute read

I recently watched the IEA Chief Economist Laszlo Varro discussing the IEA World Energy Investment 2016 report. The presentation is excellent and well worth watching.

One section of the presentation worried me

We are still in an age where renewables are already growing but the European and American nuclear fleet is still more or less in tact. That matters because nuclear both in Europe and the United States is still significantly bigger than wind and solar combined.

Already this decade, if you compare the wind and solar investments and the decommissioning of nuclear power plants this decade Europe and the United States have spent an average of 23 USD billion a year in building wind mills and solar panels that do not contribute to decarbonisation at all but simply compensate for decommissioned nuclear power plants, replacing one type of low carbon production with another type of low carbon production.

This is just a taste of things to come – the real crunch time for the existing nuclear fleet will come only ten years from now.

How does the decline of nuclear compare to the rise of renewables? Are we completely undoing the progress in renewable deployment by our attitudes towards nuclear? I decided to take a look at what has happened to nuclear in the US & Germany this century.

This analysis looks at changes in both capacity [GW] and annual generated electricity [TWh/yr]. If the distinction between capacity and generation is not clear you might find this earlier post helpful.

capacity [GW]

United States 2000 2014 Delta % change
Nuclear 105 104 -1 -1%
Renewables 3 76 73 2596%
Total 108 180 72 67%
Nuclear 22 12 -10 -46%
Renewables 6 77 71 1147%
Total 29 90 61 213%
United States & Germany        
Nuclear 127 116 -11 -9%
Renewables 9 153 144 1598%
Total 136 269 133 98%

Nuclear capacity in the US has remained stagnant this century. German nuclear capacity has reduced by almost half. The majority of this capacity shut down after the 2011 Fukushima disaster in Japan shifted the political climate in Germany.

Renewable capacity has increased immensely by a factor of around fifteen times for the US & Germany combined. Combining both nuclear & renewables together the net increase in clean generation across both countries is 132 GW. New renewables capacity far outweighs the decline of nuclear.

But - these capacity numbers are potentially misleading. The operating patterns of nuclear and renewables are different. A GW of nuclear capacity is not equivalent to a MW of renewables - see this post on capacity factor if this isn’t clear.

Nuclear plants operate as baseload plants for almost the entire year. Renewables are driven by the availability of wind or solar so operate much less. 1 MW of nuclear is therefore more valuable than 1 MW of renewables, because the same nuclear capacity will generate more low carbon electricity.

To improve our understanding we now take a look at data for annual electricity generation [TWh/yr].

generation [TWh/yr]

United States 2000 2014 Delta % change
Nuclear 754 797 43 6%
Renewables 20 226 205 1018%
Total 774 1,023 249 32%
Nuclear 161 92 -69 -43%
Renewables 9 95 86 911%
Total 170 187 17 10%
United States & Germany        
Nuclear 915 889 -26 -3%
Renewables 30 321 291 984%
Total 944 1,210 266 28%

The story of nuclear generation is the same as capacity – stagnant in the US with a decrease of around 50% in Germany. Renewables generation has increased around ten times in the US & Germany combined. This is quite a bit less than the fifteen times increase in capacity.

Combining nuclear and wind together we see a net increase in annual clean generation of 265 TWh this century. Nuclear has taken a step backward in Germany, but it is not enough to offset the progress of renewables.

This data also shows is the lower capacity factor of renewables. A 98% increase in clean generation capacity has only led to a 28% increase in clean generation. This is the effect of the lower load factor of renewable capacity.

Replacing nuclear with renewables is not only substitution of one form of clean generation with another. It is also substitution of high load factor with low load factor, and dispatchable with intermittent generation.

The good news is that on balance we are making progress. The decline of nuclear is not ideal but it is not wiping out the progress of renewables - but it is still holding back our decarbonization effort.

Thanks for reading!


US capacity data from the EIA. Renewables are ‘Wind’ and ‘Solar Thermal and Photovoltaic’.

German capacity data from Eurostat. Renewables are ‘Wind Main Activity’, ‘Wind Autoproducers’ and ‘Solar Photovoltaic’.

US & German annual generation data from the IEA Monthly Statistics. Renewables are ‘Geothermal/Other’.