A couple of days ago my Twitter feed relayed the information that wind power production grew faster in China in 2012 than it did for coal, and naturally this was classified as good news. Anyone who knows a little about the rate of growth in Chinese coal plants will realize this is a headline that will require a dash cold water to be tossed upon it.
Yes it does appear that wind production increased more than coal. What is the reason for this? The original news report, written by a Greenpeace “climate and energy campaigner”, said it was the following:
So it seems that some of the total coal capacity was not used last year, due to higher coal and transport costs, and increased costs of environmental protection.
Unfortunately this does not seem to be the real reason at all, which is actually quite clear if you look at the numbers in the report. Here they are: Coal expanded 12 TWh in 2012, wind expanded 26 TWh, and hydro expanded 196 TWh from 668 to 864 TWh. The cause of this massive expansion of hydro electric is quite simple, there was a massive drought in 2011, the year before, which caused hydro power output to be very low. In essence coal had to be ramped up a lot in 2011 to replace the lost hydro production, but the recovery of hydro output in 2012 meant that any expansion in coal output was greatly reduced by hydro. To put some numbers on this, China added 50 GW of coal, and assuming a capacity factor of 50% these plants would provide 219 TWh of output. Consequently almost all of the output you would have expected (all things being equal) from its new coal plants was offset by the increase in hydro electricity.
So, wind expanding more than coal in 2012 is simply an artefact of the intermittency of rainfall and drought.