Heat Mining in West Virginia
Producing silicon, the economic workhorse found in commodities from computer chips to aluminum beer cans, takes way more energy than lighting Wrigley Field for a doubleheader...It's a very heat-intense process.CHP (combined heat and power) is a rapidly expanding way to improve efficiencies, for systems that need both heat and electric power for operations. That includes your home, by the way, if you like being warm in winter, and having hot water for showers and power for electric lighting. One of the more interesting CHP applications coming along is home fuel cells that provide power, hot water, and space heating. When heat-powered refrigerators are better developed, waste heat from your home power generation may even power your refrigerator--reducing your power load.
Quartz rocks placed in electric-arc furnaces exude oxygen as superheated gas, leaving molten silicon. Just venting all that heat without setting something afire is a concern. But what has been a problem has become an opportunity for a Westmont-based firm, Recycled Energy Development LLC.
...It will cost an estimated $45 million to $55 million to build the system, which will generate more than 40 megawatts of electricity. That is enough to power 20,000 homes and will supply about one-third of the silicon-maker's power needs, said Sean Casten, Recycled Energy's chief executive....Globe Metallurgical will buy that electricity for 25 years at a set cost, said Casten, because unlike juice from the electric company it is possible to predict decades ahead how much this electricity will cost.
"We know the cost of our capital," Casten said, "and we know the cost of our fuel because it's zero. We're recovering waste heat."...Because electricity is the highest single cost for West Virginia Alloys, locking in a price for 25 years for a major chunk of that power is attractive. Another benefit may come from the new federal energy law that could subsidize plants that recycle waste heat.
Nearly all electricity generated in West Virginia comes from burning coal, Casten said, so when the recycling-energy operation kicks in two years from now it will replace electricity associated with an estimated 290,000 metric tons of greenhouse gases annually.___Tribune
Efficiencies of up to 90% using CHP are possible, which in big industry amounts to huge savings in both money and fossil fuels.
Interestingly, the world's most efficient CHP plant utilises biomass fuels.
This list of biomass projects contains several CHP plants