UC/Cal State project promotes using waste heat from power generation to heat and cool buildings
BERKELEY – Heating homes with the waste heat from electricity generation, though common in many small European towns, has never attracted much attention in the United States, despite its obvious efficiency.
Now, however, with the advent of small units that make "combined heat and power" feasible for single buildings, and with new financial support from the U.S. Department of Energy (DOE), researchers from three California universities are eager to promote this alternative widely.
Last month, DOE announced $1.5 million in funding for five regional U.S. projects to encourage conversion to combined heat and power (CHP), also known as co-generation.
The University of California, Berkeley's Energy & Resources Group (ERG) will be the prime contractor for the Pacific Region CHP Application Center network, dubbed the PRAC network. It will receive $300,000 from DOE over the next one-and-a-half years to study the feasibility of CHP for small businesses and encourage its use in commercial and industrial as well as residential settings. UC Berkeley and its partners on the project, UC Irvine and San Diego State University, expect the network to continue with a mix of private and public funds, working through the California Energy Commission, according to lead researcher Daniel Kammen, a professor in ERG and in the Goldman School of Public Policy, and head of UC Berkeley's Renewable and Appropriate Energy Laboratory (RAEL).
"Combined heat and power is a step toward greater energy efficiency that we know works and we can move toward today, as we investigate other solutions that might or might not pan out in the future," said Timothy Lipman, assistant research scientist at ERG. "CHP focuses on end-user efficiency, which is a big part of the solution to reducing energy use and greenhouse gases."
UC Berkeley has had a co-generation plant for many years, operated by outside contractors to supply both steam heat and enough electrical power to feed the campus, while San Diego State University just completed an upgrade of its co-generation plant to 14 megawatts of electricity. The planned UC Merced campus also will have a significant CHP component, Lipman said, and he hopes that UC Berkeley will consider CHP as part of a new green-building program mandated by the UC Board of Regents in July.
In the entire United States, more than 60 gigawatts of power is now generated by CHP installations, according to the DOE, which has established a goal of 92 gigawatts by 2010. Lipman, a research associate in ERG, said that capturing waste heat can increase energy efficiency by about 20 to 30 percent for buildings such as hospitals, laundromats or laboratories that have large heating needs.
"It's becoming easier to integrate a small power plant into a building's energy system," Lipman said. For single-family homes, he added, "people are even talking about household fuel cells that would integrate with your hot water heater so it wouldn't have to work so hard. It probably will be at that scale in the future."
The PRAC network, a partnership between UC Berkeley's ERG, Scott Samuelsen, Vince McDonell and Jack Brouwer of UC Irvine's Advanced Power and Energy Program and Asfaw Beyene of SDSU's Industrial Assessment Center, will work with a broad coalition known as the Pacific Southwest CHP Initiative on educational, project screening and policy efforts in California, Arizona, Nevada, Hawaii and the Pacific territories, Lipman said.
"The focus of this is to get combined heat and power systems installed," Lipman said, so initially PRAC will concentrate on helping businesses assess the feasibility of CHP systems. These most likely would be conventional natural gas combustion systems, systems powered by gas from wastewater treatment or landfills, or small natural gas turbines - microturbines - connected to a generator, with waste heat channeled to the heating and even air-conditioning system.
"The incentive for business is more efficient power use, thus saving on your electricity and potentially your gas bill, maybe reducing the load on your boilers, and greater power reliability," he said.
The PRAC team also will conduct case studies of existing systems and publicize their findings, examine regulatory policy and other issues that affect the deployment of CHP technologies, organize training workshops, and eventually set up demonstration projects and a learning center for the public.
"The PRAC center also will examine the potential for integrating combined heat and power with renewable energy, which has tremendous potential, as well as with new, more reliable grid designs," Kammen said. An additional important benefit includes reducing the need for costly and controversial grid transmission and distribution system upgrades, an important issue in light of the recent east coast power blackout and the condition of the U.S. electrical grid.
Kammen and Lipman also hope to encourage "distributed generation," that is, the building of small energy generators distributed widely instead of large centralized power plants.
"There are clean distributed generation sources out there, like natural gas or landfill gas-powered fuel cells, that can offer many of the same environmental benefits as renewable sources," Lipman said. "With distributed generation you get similar or better electrical efficiencies as central power generation and no distribution costs or energy losses. Then, if you can capture the waste heat, you can get overall thermal efficiencies at 80 to 85 percent. You're getting all that heat back.
"It's sort of like the situation with hybrid cars. Just as there is a lot we can do with hybrid cars today while we are working on better, longer-term options, such as hydrogen fuel cells, so there is a lot we can do with CHP systems while we work toward expanded use of renewable energy sources."
The CHP grants are among 187 energy efficiency grants, totaling $17.39 million, awarded by DOE last month through its State Energy Program Special Projects competition. The federal dollars will help states improve energy efficiency in schools, homes and other buildings, promote energy-efficient industrial technologies, and support renewable and distributed energy sources.
The UC/Cal State award was made through DOE's Seattle Regional Office and the California Energy Commission's Public Interest Energy Research (PIER) program.