Technology

This article is the result of some very interesting discussions on the potential of coal, nuclear and wind/solar to supply the rapidly growing energy needs of the developing world. In that article, I estimated that nuclear is roughly an order of magnitude less scalable than coal, but more than double as scalable as wind/solar. These estimations were challenged by both nuclear and wind advocates and, as such critical discussions often do, have prompted much closer investigations into this issue. In particular, data pertaining to the near-term prospects of nuclear energy in China, the nation accounting for fully 43% of nuclear plants currently under construction, has been analysed in more detail.
The results of this analysis confirmed my estimations above fairly well, but only under two very important assumptions: 1) that all the nuclear plants currently under construction in China are successfully completed roughly 6 years after construction commenced and 2) that it will be a very long time before we experience another black swan event like Fukushima.

Recent nuclear developments in China

China has invested heavily in nuclear energy over the past few years, leading to a rapid increase in construction activities. Data from the World Nuclear Association has allowed for the creation of the following plot of started and completed nuclear reactor capacity in China. Note that the plot shows the cumulative started and completed nuclear capacity from the start of 2007.

Nuclear vs. wind

Wind power has also been growing rapidly in China since 2008.  The relative simplicity and modular nature of wind causes much shorter construction times than nuclear, and has therefore led to a much more immediate impact. However, the true scalability of a technology must be tested over substantially longer time periods than the 6 year nuclear construction period, implying that this time-lag is not highly relevant when considering the longer-term energy future of China.

Under the assumption that wind construction times are essentially negligible, we can therefore compare the rate at which new investments are committed to wind and nuclear energy. To make this comparison, one also has to take into account the difference in capacity factors between wind and nuclear energy. This is a rather sensitive area, but I will use data from the BP Statistical Review and the World Nuclear Association to make a reasonable estimate. At the end of 2013, China had 15 GW of operational nuclear and 91 GW of operational wind. In terms of generation, nuclear delivered 110.6 TWh and wind 131.9 TWh. This implies that one unit of nuclear capacity delivers about 5 times as much electricity as one unit of wind capacity. This might be an over-estimate, however, since China is working hard to solve significant wind curtailment problems at present. I will therefore use a ratio of 4 in this analysis.

Using these assumptions, the Chinese wind capacity build out is compared against the Chinese nuclear construction starts in the graph below (note that wind capacity is divided by 4 in order to reflect actual electricity generation relative to nuclear). Similar to the graph above, numbers are presented from a base of 0 at the start of 2007.

It is shown that new nuclear projects were started at a tempo more than double the rate at which wind projects were completed before Fukushima and roughly at an equal rate when nuclear starts eventually recovered thereafter. This is a clear indication of the impact of a black swan event on the prospects of nuclear power, even in China. Thus, it can be theorized that nuclear scales
roughly triple as fast as wind under normal circumstances, but at an equal rate when a recent black swan event burdens the industry with additional regulations. Hopefully, we will go some decades without another black swan event so that nuclear growth rates can return to pre-Fukushima levels and maintain (or even exceed) these rates for an extended period of time.
 
It should also be mentioned that the Chinese tariff system favours wind over nuclear by paying a fixed feed-in tariff of $83-100/MWh to wind and $70/MWh to nuclear. Another important factor to consider is the reduced value of wind relative to nuclear due to the variability of wind power. Wind power also requires expensive high voltage transmission networks to transport power from good wind locations to population centers, something which is creating substantial challenges. Thus, if the playing field were to be leveled, the difference between nuclear and wind scaling rates should increase substantially.

Another important factor to consider is the CO2 avoidance potential of nuclear vs. wind. Here, there are two important distinctions to be made. Firstly, nuclear plants have a very long lifetime relative to wind, implying that more CO2 will be avoided over the lifetime of the plant. Secondly, nuclear displaces base load generation (essentially 100% coal) .