Home Cogeneration | Green Energy News

March 5, 2006 – Vol.10 No.50

HOME COGENERATION.

In the U.S. Honda has been working with Climate Energy of Massachusetts to build a combined heat and power system (CHP) that would be appealing to homeowners. (In Japan Honda has about 20,000 home CHP systems installed, they say.)

The partnership has now completed the first installation of its technology in a home in Braintree, Mass.

The home CHP system that the two are developing includes a Honda combustion engine/generator set combined with a high-efficiency furnace or boiler. Fueled by natural gas, the electric generator can provide 1.2 kilowatts of electricity. Waste heat from the generator provides about 10,000 Btu’s per hour of thermal energy that can add supplemental thermal energy to a home’s boiler, furnace or domestic hot water system.

The unit runs on demand for heat or hot water. When the home’s thermostat calls for more heat, or more domestic hot water is needed, the Honda generator starts up, waste engine heat makes hot water or hot air, and electricity is produced that can be consumed, or not. The CHP unit only comes on when heat is needed, not electricity.

The link to heat production with the system is an operational issue. People expect electricity on demand but are accustomed to the delay heating systems have in providing heat. If the CHP system were the other way around, with the generator running continuously for on-demand electricity, heat would be wasted reducing the overall efficiency of the unit. (This would likely be almost as inefficient and costly as using a portable generator to power a house.)

Other small cogenerating units being developed around the world work the same way: electricity is generated only when heat is demanded.

Depending on climate, overall annual heating energy costs may be higher than electricity costs. Colder states in particular, like Massachusetts, might see greater benefits from a home cogeneration system than a warmer climate where often neither heat nor air conditioning is needed.

Visit Climate Energy at http://www.climate-energy.com/ , Honda at http://www.honda.com/