New Options for Home Wind Power

Philip Proefrock — Fri, 12 Sep 2008 04:05:07 +0000

Utility-scale windpower is an important and growing part of the US energy portfolio. Farms ranging in size from dozens to hundreds of turbines can produce in excess of 60 megawatts of power. Plans for gigawatts of wind power are being proposed all over the globe, and new wind farms are regularly being proposed that outstrip one another to be the largest in their respective locations, or in the world. At the far end of the scale, the largest size wind turbines have a rotor diameter of 126 meters (413 feet), and are estimated to be capable of producing 20,000,000 kilowatt hours of electricity annually (enough to power as many as 5000 European homes). Since the power generated by a turbine increases exponentially as it gets larger, new turbines will continue to grow in size.

But small-scale turbines are perhaps a more exciting realm of development. The standard, propeller-style turbine is well established, and there are many suppliers for this kind of generator in a range of sizes. In 2007, Home Power Magazine had a roundup of more than a dozen small wind turbines ranging from 8 feet to 56 feet in diameter (the latter of which is far larger than even a large, inefficient household would need for their power requirements). Green Building Elements had a review of this article last year.

Household co-generation system

Philip Proefrock — Mon, 05 Feb 2007 15:45:06 +0000

Co-generation is a systems approach for producing poth power and heat. Combined heat-and-power (CHP) plants produce electrical power, and use the heat from that production to also provide heat to local buildings (often through underground steam or hot-water piping systems). These systems have been most often found at hospitals and universities, where a large number of buildings can be efficiently served by a combined facility such as this. But new systems are bringing this same technology into the home.

Micro-CHP units are new to the US, with the first installations just beginning in the northeast. The technology for these units is not brand new, however. There are more than 30,000 homes with these units installed in Japan, where the gas utilities have been promoting them. In Britain, 80,000 under-counter micro-CHP systems are on their way and will be installed in the coming years.

Household micro-CHP systems use a natural gas powered electrical generator to produce electricity. The heat produced from that part of the system is used either to create hot air (as with a traditional forced-air furnace system) or to create hot water (for radiator or radiant floor heated homes). Because the heat is being productively used, rather than going up the chimney of a distant power plant, and because the electricity is being locally produced, rather than being subjected to the losses inherent in power transmission, the micro-CHP is "triple the efficiency of power delivered over the grid."

Micro-CHP systems are most likely to be used in states that offer net metering to their customers, since they will likely produce more electricity than the household needs while they are cycled on.

Having your own power plant in your basement also means that, with the right connections to properly operate the system, blackouts are no longer a concern. Micro-CHP systems are not inexpensive, however. They can be as much as double the cost of a comparable high-end furnace. But, with the electrical savings, they can pay for themselves within a few years at present rates.

Green Options » home power generation

New Options for Home Wind Power

Household co-generation system