The Gatais used to frown when they received power bills that routinely topped $200. Last September the couple moved into a 1, 500-square-foot home in Premier Gardens, a subdivision of 95 " zero-energy homes" (ZEH) just outside town. Now they' re actually eager to see their electricity bills. The grand total over the 10 months they' ve lived in the three-bedroom house: $75. For the past two months they haven' t paid a cent.
ZEH communities are the leading edge of technologies that might someday create houses that produce as much energy as they consume. Premier Gardens is one of a half-dozen subdivisions in California where every home cuts power consumption by 50%, mostly by using low-power appliances and solar panels.
Aside from the panels on the roof, Premier Gardens looks like a community of conventional homes. But inside, special windows cut power bills by blocking solar heat in summer and retaining indoor warmth in winter.
The rest of the energy savings comes from the solar units. They don' t just feed the home they serve. If they generate more power than the home is using, the excess flows into the utility' s power grid (电网). The residents are billed by " net metering" : they pay for the amount of power they tap off the grid, less the kilowatts (千瓦) they feed into it. If a home generates more power than it uses, the bill is zero.
That sounds like a bad deal for the power company, but it' s not. 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 solar expert Mike Keesee. " That lets us avoid building costly plants or buying expensive power at peak usage time. "
What' s not to like? Mostly the costs. The special features can add $25000 or more to the purchase price of a house. Tax breaks bring the cost down, especially in California, but in many states ZEHs can be prohibitively expensive. For the consumer, it' s a matter of paying now for the hardware to save later on the utilities.
