[Paleopsych] "Zero Energy Homes"

[Steve Hovland]

http://www.msnbc.msn.com/id/8852127/site/newsweek/
Aug. 15, 2005 issue - Nicholas and Loan Gatai used to cringe when they 
received power bills that routinely topped $200. Last September the 
Sacramento, Calif., couple moved into a new, 1,500-square-foot home in 
Premier Gardens, a subdivision of 95 "zero-energy homes" just outside town. 
Now they're actually eager to see their electric bills. The grand total 
over the 10 months they've lived in the three-bedroom, stucco-and-stone 
house: $75. For the past two months they haven't paid a cent.
Almost unknown outside California, ZEH communities are the leading edge of 
technologies that might someday create houses that produce as much energy 
as they consume. Premier Gardens, which opened last summer, is one of a 
half-dozen subdivisions in California where every home cuts power 
consumption by at least 50 percent, mostly by using low-power appliances 
and solar panels. Several more are under construction this year, including 
the first ZEH community for seniors.
Aside from the bright patch of solar modules on the roof, Premier Gardens 
looks like a community of conventional homes. But inside, it's clear why 
they save energy. "Spectrally selective" windows cut power bills by 
blocking solar heat in the summer and retaining indoor warmth in cold 
weather. Fluorescent bulbs throughout use two thirds the juice of 
incandescents. A suitcase-size tankless hot-water heater in the garage, 
powered by gas, saves energy by warming water only when the tap is turned 
on.
The rest of the energy savings comes from the solar units. Set flush with 
the roof tiles, the two-kilowatt photovoltaic panels unobtrusively turn the 
sun's rays into AC power with the help of an inverter in the garage. An LED 
readout shows the system's electrical output. Just looking at it can give 
owners a warm feeling. "When I pull into the garage, sometimes I just like 
to look at the Sunny Boy [inverter] to see how much power we've generated," 
says homeowner Kurt Gonzales, whose family bought a 2,200-square-foot 
house.
In ZEHs, the solar production doesn't just feed the home it serves. If the 
panels are generating more power than the home is using-when the house is 
empty during a sunny day-the excess flows into the utility's power grid. 
Gonzales and other residents are billed by "net metering": they pay for the 
amount of power they tap off the grid, less the kilowatts they feed into 
it. If a home generates more power in one month than it uses, the bill is 
zero.
That sounds like a bad deal for the power company, but it's not. The 
Sacramento Municipal Utility District's solar expert Mike Keesee says 
that's because solar homes produce the most power on the hot sunny 
afternoons when everyone rushes home to turn up the air conditioner. "It 
helps us lower usage at peak power times," says Keesee. "That lets us avoid 
building costly plants or buying expensive power at peak usage time."


Steve Hovland
www.stevehovland.net