Two-thirds of the fuel used in conventional power plants is exhausted as wasteheat to oceans, rivers and the atmosphere. In total, U.S. power plantswaste more energy than most countries – including major economies likeJapan – consume for their entire economies. This waste heat can berecovered and put to productive use through combined heat and power(CHP) systems. In addition, the United States has abundant renewablesources of thermal energy, including biomass, geothermal, solar, andnatural sources of air conditioning.
The Thermal Renewable Energy and Efficiency Act of 2010 (TREEA, S.3626 / H.R. 5805) was introduced by Sens. Al Franken (D-MN) and Kit Bond (R-MO) in the Senate, and Rep. Betty McCollum (D-MN), with Reps. JayInslee (D-WA) and Paul Tonko (D-NY) as original co-sponsors, in theHouse.
- District energy systems provide a cleaner way to heat and coolcommunities, by capturing waste heat that would otherwise be unused, orusing renewable resources such as geothermal, water, solar, or biomass.
- District energy aggregates thermal loads to a scale that makes itpossible to use thermal energy sources that would not make sense on asingle-building basis.
- District energy systems can help strengthen energy security byreducing the need for imported foreign oil and improve economicdevelopment by keeping energy dollars in the local economy.
- There are district energy systems in all 50 states, but there aremany opportunities to expand existing systems or build new ones.Under-utilization of district energy in the United Sates is not atechnology issue, it’s a policy issue.
- In Denmark, 80 percent of heating and cooling is drawn from district energy systems.
- District Energy St. Paul has built the largest district energysystem in the United States, serving 85 percent of downtown buildings.Its thermal energy comes from 70 percent renewable sources, with thehope of achieving 100 percent renewable in the future. It has plans toincorporate a large solar-thermal energy project, the first of its kindin the United States.
- District energy has the potential to draw waste heat not only frompower plants, but from industry as well. For example, District EnergySt. Paul hopes to capture heat from a paper recycling plant a few milesfrom downtown.
- To cool its campus, Cornell University pulls cold water from thebottom of Cayuga Lake through a district energy system, reducing the use of cooling electricity by 87 percent campus wide, cutting carbondioxide emissions by 56 million lbs per year, and eliminating 40,000 lbs of CFCs.
- A Seattle district energy system uses waste wood to serveapproximately 200 downtown buildings, reducing carbon dioxide emissionsby 55,000 tons per year.
- Buildings that use district energy have more leasable space becauseboilers, chillers, chimneys, and other heating and cooling equipment can be removed.
- The Thermal Renewable Energy and Efficiency Act of 2010 (TREEA) isintended to stimulate investments in low-carbon thermal energyinfrastructure, focusing on use of renewable energy sources to supplyheating and cooling. Major provisions include a renewable thermalproduction tax credit, expanded availability of tax-exempt bonds fordistrict energy infrastructure, and modified authorization forinstitutional sustainable infrastructure.
- If passed, TREEA will act as a foundation and set importantprecedence for future energy policy. Several other bills have beenintroduced to address other thermal energy policy gaps.
Dan Kammen Advising World Bank on Energy Issues