Dear Pablo,

I keep hearing that China is currently building around one coal-fired power plant per week. Even the presidential candidates repeat it. Is it true? Do you know any sources for it? The candidates also keep talking about “clean coal.” What’s the story with that?

Good question. I have heard various figures from various sources, and some say the number is actually higher. According to John Ashton, the top climate change official at the U.K. Foreign Office, “China is now building about two power stations every week.” Joel Blum, the John D. MacArthur Professor of Geological Sciences at the University of Michigan, says, “Coal-burning plants are being built in China at an alarming rate — something like two per week.”

In the vice-presidential debate, Joe Biden claimed, “China is building one to three new coal-fired plants burning dirty coal per week. It’s polluting not only the atmosphere but the west coast of the United States. We should export the technology by investing in clean coal technology.” So if foreign officials, college professors and even presidential campaigns are citing this figure, there must be something to it, right? Well, unfortunately, no one cites a firsthand source.

So let me go straight to the numbers. A simple way to estimate an actual number is to start by extrapolating the coal energy use by China to estimate the current annual demand growth. According to the U.S.Energy Information Administration, “at the end of 2005, China had an estimated 299 gigawatts of coal-fired capacity in operation.” The administration also reports that “coal use in China’s electricity sector is projected to increase … at an average rate of 4.1 percent per year.” At this rate, China now uses 337.3 gigawatts of coal-fired electricity and will be adding 13.83 gigawatts in the coming year. One gigawatt is equivalent to the capacity of a typical nuclear power plant!