You will notice in this diagram from the Energy Information Administration (EIA) depicting the total electricity flow in the US for 2008 that “conversion losses” account for 63% of the energy generated. Got that?! Nearly two thirds of the energy used to make electricity, 51% of that from coal, 21% from nuclear, and 17% from natural gas, is lost as heat. (Another 3% or so is lost in transmission and distribution.) What do coal, nuclear and gas have in common? They are all deployed in central power plants. You know those great honking monolithic hyperbolic cement monstrosities that dot the landscape all over the world blowing steam?
Those are cooling towers. If power plants don’t use cooling towers, they will likely draw water from a local river and circulate the cool water through the plant and dump the hot water back into the river causing considerable thermal pollution – destroying fish and other aquatic life.
Senators Bernie Sanders and Jeff Merkley have introduced the Thermal Energy Efficiency Act. This would provide considerable funding for combined heat and power, waste energy recovery, and district energy projects. Sanders’s press release notes “…combined heat and power represents roughly 9 percent of our existing electric power capacity today, but if we moved to 20 percent by 2030, we could avoid 60 percent of the projected growth in carbon dioxide emissions in this country.”
An article in Grist by Dave Roberts discusses some of the ins and outs, including the fact that “…a) this is an enormous opportunity to cost-effectively reduce climate pollution, and b) there’s enormous, pent-up demand for coordinated resources and assistance.”
I heard a speaker, Al Forte from Nexant, put it another way by saying there’s 800 GW of generating capacity in the US and it’s operating at an average of 28% efficiency. He more or less characterized this as criminal and wondered why there isn’t more use of cogeneration. See this post for more on this, including a comment there from the very good folks at Recycled Energy Development – led by the visionary Tom Casten – that “EPA and DoE studies suggest technologies like cogeneration and waste heat recovery could produce 40% of the nation’s electricity…”
Frankly, I wish that Steven Chu was hammering heat recovery. White roofs are a terrific concept, and practical, to be sure, but when you are talking about the massive energy loss and thermal pollution involved with power plants, then it is indeed criminal to not mandate heat recovery.