Renewable Energy

There’s a bunch of buzz about a CleanTechnica analysis claiming to show that “Renewable Energy [is] Now Growing Faster than Coal in China”. I wish the analysis were right. But if you dig into the underlying numbers, the reality is nowhere close. Here’s the Xinhua source for the underlying numbers. We can learn a few things from it. What CleanTechnica is really saying is that the amount of capacity of nuclear, hydro, and renewables under construction at the end of 2009 was greater than the amount of thermal (mostly coal) capacity under construction at the same time. That’s impressive, but it’s not the same as what’s claimed. First, there’s a big difference between “nuclear, hydro, and renewables”, and, well, renewables. Xinhua says that there were 96.2 GW of nuclear/hydro/renewables under construction and 80 GW of thermal, but it also says “under-construction generation capacity of hydropower and nuclear power exceeds that of thermal power by 10 million kilowatts”. That means that only 6.2 GW of the capacity under construction was actually renewables – less than 10% of the amount of coal capacity being built. So much for parity. Second, the analysis focuses on Xinhua’s snapshot of what was happening at the end of 2009 while ignoring its projections for 2010. And those projections are less optimistic. They indicate that China is expected to start construction of 25 GW of nuclear, hydro, and renewables this year, set against 45 GW of coal, nearly twice as much. Finally, generating capacity is not the same as output. Capacity factors for wind tend to be around 33%; those for hydro are usually between 40% and 50%; coal tends to be 75% or more; and nuclear can often be greater than 90%. (The capacity factor for a generating unit is the ratio of electricity actually produced to the amount that would be produced if the unit ran at its rated capacity full time.) That means that 1 GW of wind generates less than half the total power of 1 GW of coal. It is thus not true that “hydro, nuclear and wind power should account for 26% of the country’s electricity generation” by the end of the year – it may account for 26% of China’s generating capacity, but that will be equivalent to a substantially smaller fraction of action generation.