Off the Grid
Energy-efficient homes are becoming a reality.
Solar panels and large overhangs that shade the home from the sun create energy savings.
This fall, the Florida Solar Energy Center (FSEC) will select a Florida home builder to help create a community of 20 or more zero-energy homes. At least a dozen builders from across the state have applied, even though the project doesn't come with any funds, just technical assistance from FSEC. "We want to take this technology and try to transfer that to the builders," says Stephen Barkaszi, senior research engineer with FSEC in Cocoa.
The concept of zero-energy homes (ZEHs) has been around for several decades, but rising energy costs and concern over CO2 emissions from power plants are sparking more interest from builders and consumers alike. Already in California, builders are mass-producing the energy-efficient models.
The idea is that over a year, the home will produce as much energy as it uses. Although the energy produced could be from any renewable resource, including wind, biomass or hydro, the only ZEHs being built today use solar.
Design of ZEHs is based on three features: An energy-efficient "envelope," high-efficiency appliances and a renewable source of energy. The envelope consists of the walls, windows, roof and floors.
In Florida, one of the most effective ways to save energy is with the roof, says Barkaszi. "White's the best," he says.
Lighting also makes a big difference in overall energy consumption. Compact fluorescent light bulbs are leading the way in energy efficiency because of their improved brightness and increasing affordability. Wal- Mart has worked with GE to lower the cost of the bulbs and is beginning a major sales push. The second part of the ZEH system is energy-efficient appliances. Tankless water heaters are one component, but in Florida perhaps the most important item is a hig-efficiency air-conditioning system.
Finally, the renewable energy component of a ZEH is a solar system. Photovoltaic systems cost $8 to $12 per watt, with the average 2,200-sq.-ft. home without a swimming pool requiring about 4 kilowatts. That's $32,000 to $48,000. The 2006 Legislature enacted the Florida Renewable Energy Technologies and Energy Efficiency Act, which offers rebates of $500 for solar water heaters, $100 for solar pool heating systems and up to $20,000 for residential installations of photovoltaic systems.
Zero-energy homes typically cost at least 25% more than other homes. But more limited improvements might add only 5% or 10% to the cost and recoup that amount in only a few years. "It's at a point of acceptance," says Barkaszi. "People are wanting to do a little bit more."
Florida ranks 27th in electricity use per capita, with 12,792 kilowatt hours a year per capita, according to the California Energy Commission. In terms of gasoline use per capita, Florida ranks 26th, with 496 gallons per capita.