Cogeneration for Homes | Green Energy News

July 19, 2007 – Vol.12 No.17

COGENERATION FOR HOMES: HONDA REPORTS 50,000 UNITS SOLD.

Pardon the pun. Here’s a burning question: Is it more efficient to burn the world’s remaining natural gas supplies in large grid-connected powerplants or use it for distributed cogeneration plants (combined heat and power), some small enough to be used in homes?

The answer may be convoluted and needs to be looked at on a case-by-case, powerplant-by-powerplant basis since some large powerplants are already cogenerating facilities with heat used for industrial processes.

Still, closer to the end use - such as heating and powering your home - is typically the more efficient utilization of any resource, in this case one that is nonrenewable.

Honda has announced that it has sold 50,000 units in Japan of its ECOWILL home cogeneration product since its introduction in 2003. The unit runs on natural gas for a total combined efficiency of 85.5 percent when generating both heat and electricity. It has an electrical output of 1 kilowatt per hour and a heat output of 2.8 kilowatts per hour (more than 9500 Btus per hour), neither of which is ample to provide all the power, all the heat or all of the domestic hot water all of the time

However, for much of the day that’s all the power thats needed and, depending on the season, all of the heat needed for space heating.

A variation of Honda’s ECOWILL is sold in the US by Climate Energy as Freewatt (tm). Freewatt has slightly more power and heat output and is sold complete with a heating system; a boiler for hot water or a furnace for hot air.

Climate Energy explains that Freewatt is heat-led. That is, when there’s a demand for heat or domestic hot water the unit will turn on and supply both heat and electricity. If not enough heat is supplied the auxiliary furnace or boiler will also kick in.

In extended periods of cold weather the unit could run continuously, 24/7, providing moderate levels of heat and 1.2 kilowatts of power. At any time in its operation electricity not absorbed by the house can be sold back to grid provided the local utility offers a net-metering, electricity buyback program.

The Climate Energy Freewatt can produce enough electricity to pay back the additional capital cost over a conventional heating system in as little as 4 to 5 years.

In Japan a federation of three major organizations in the gas energy industry intends to sell a total of 235,000 units of ECOWILL by 2011.

Honda is slowly and steadily moving into the home energy business: The company’s thin-film solar electric products are now on sale in Japan in limited numbers. If Honda does as well with home energy as it does with cars, the change in the way we heat and electrify our homes should be revolutionary, and perhaps make much better use of remaining nonrenewable sources of energy.

Links:

Honda Worldwide http://world.honda.com/

Climate Energy http://www.climate-energy.com