Michael Holigan: Nature people who worship the sun do something many of us ignore. Sunlight is the source of almost all energy on this planet. At this research center Texas Utilities test futuristic ideas for converting the sun's energy to daily use. Someday you may be able to turn this little solar powered fellow loose in your yard where he'll manicure the lawn all by himself. And even sooner than that you'll be able to cut the amount of electricity by if you roof your house with solar shingles. Although they look a lot like common composite shingles, solar shingles contain small silicon crystals that create electrical charges when exposed to sunlight. Tiny wires transfer the electricity to batteries where it's stored and used.
J.B. Hedrick: It's very flexible stuff and it's about seven or eight feet long and you just staple right through the backing. And on the back there's a couple of wires that come out, a plus and a minus, and you just pull these through inside the sheathing.
MH: The problem with both of these inventions is that right now they're not practical. The solar sheet, as it's called, costs $2,000 and refuses to work on hills or in cloudy weather and it costs about $10,000 to install enough solar shingles to power ten light bulbs.
J.B.: I think in a few years as the price comes down you'll probably see more of these used in urban areas as supplemental power or for people that have a desire to, to be green. I mean, that, that seems to be a growing market.
MH: But while we're waiting for the future we can take advantage of the sun's power right now, not just with active solar energy, which is electricity converted from sunlight, but with passive solar energy, which is energy you can collect or deflect, depending on how you design your home.
Barbara Harwood: If every house in this country used passive solar heat, and they could in every house in this country, we'd save 50% on the nation's heating bill, 50%.
MH: Barbara Harwood is a contractor and author. She helped Paul and Elana Westbrook build a home that uses passive solar to collect free heat in the winter and keep heat out in the summer. In keeping with the passive solar strategy the length of the house sets east to west. You'll notice there are few windows here on the north and trees instead of windows on the west, the hottest, sunniest side. That cuts cooling bills in the summer. The exterior walls are also a factor. Looks like a giant cooler.
Paul Westbrook: This a section of the exterior wall of our house. All the walls are made of Styrofoam core with strand board on the side and they're all bonded together and it's a very rigid structural system.
MH: How does this really compare with most insulation systems?
PW: It's a little thicker than a standard wall and gives you much better resistance. There's no what's called thermal bridging.
MH: The house's metal roof also helps. During hot summers it reflects heat away from the house.
EW: Come on in.
MH: Wow, this is great. One of the first things you'll notice inside is the exposed ductwork. It gives an artsy look to the home, but it's also practical.
EW: Because it's inside you're not going to lose nice air conditioned air into a hot attic or nice warm air into the cold outside.
MH: The southern windows bring in light, but little heat. Ceiling fans add circulation and blinds that lower from the top help control sunlight. The design of outdoor overhangs is also critical. They're placed at an angle that keeps direct sun out in summer, but allows the sun in during the winter when it sets lower on the horizon. All of this is passive solar.
BH: Where you put the windows and how you sit the house on the lot are the two big ones. And then third how you protect the house from the sun in the summertime.
MH: The Westbrooks do use active solar collectors that are practical. They pump water to sprinkle the lawn and solar collectors on the roof heat water.
PW: And we get most of our hot water from solar, active solar heating.
MH: The roof collectors transfer heat through a heat exchanger and into hot water. And what Paul calls his mechanical room, the heat exchanger works alongside a geothermal heat pump which uses the earth to supply air conditioning and heat. In winter, water circulating through the loop absorbs heat from the ground and carries it into your home. The pump unit then compresses the heat to a higher temperature and forces it through the air ducts and into your home. In the summer the geothermal unit works in reverse. It removes heat from your home and transfers it back through the loop to the cool earth. The Westbrooks say that the geothermal pumps slashes heating and cooling costs. Well, it cost a penny a day to have hot water. What does it cost to heat and cool the house?
PW: My worst month was 86 cents a day in January to heat and in June of this year we ran 72 cents to cool the house. My worst electric bill's been $69.00.
MH: That's $69.00 for a 3,000 square foot house, about one-half to a third of what neighbors with more conventional homes might pay. As for recovering the cost of installing these systems, the Westbrooks say it may take seven years.
PW: I think it's just kind of a balance. We wanted to impact the planet as lightly as we could and we wanted to lower the burden on our energy system. And then the bottom line on a lot of it, it was good for us. It was good for our pocket.
MH: In this house solar energy does save money, but just as important to the builder and occupants is the feeling of harmony with nature that the use of solar energy brings to their home.
Contacts:
American Solar Energy: 303-443-5482
Paul and Elana Westbrook:
pwest@topher.net
Episode 50 1997 - 98 Season
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