Here's another great tip from BobVila.com. If you have a south-facing roof, you re probably paying too much for hot water. Over a million and a half homes and businesses in the U.S. have already invested in solar hot water systems, and they re reducing their fuel use by as much as three quarters, even in cooler climates. That s a huge dollar savings, but over 20 years, one solar water heater keeps 50 tons of carbon dioxide out of the atmosphere and takes us one more step toward breaking that nasty fossil fuel habit. Solar technology has come a long way since the 70s and 80s: Even where it s cold, one or two solar collectors on the roof taking up about 65 square feet can provide 65 percent of the hot water used by a family of five. Best of all, it s sustainable solar power doesn t run out! Because this is your roof and any equipment is only as good as its installation, you want to be sure your installer and the system you buy are certified by the Solar Rating and Certification Corporation or the Florida Solar Energy Center. Many states and utilities offer rebates of 15 percent or more on installation as well as other incentives to homeowners and businesses for going solar. Don t forget to check the Department of Energy s Database of State Incentives for Renewable Energy, or D-S-I-R-E, to see how you can save some green while you go green! Find out more at BobVila.com: The ultimate home improvement web site! BobVila.com 2008

Photovoltaic panels are being installed on the roof. Bob talks with Jeff Wolf from groSolar about the photovoltaic panels. As sunlight hits the panels, electricity is generated from the photons. That direct current comes down through a wire into the house and is channeled into an inverter. The inverter is in the basement of the home. The inverter converts the direct current from solar power into an alternating current. That alternating current is fed into the main electrical panel and feeds the house with solar power. When the house is not using its electrical energy generated from the panels, the electricity is fed back into the utility grid and spins the meter backwards, creating a credit for the customer. The photovoltaic panels are a clean way of generating energy for the household. Many states have programs to help subsidize the cost of installing solar panels to make them more affordable for homeowners. Many parts of the country are seeing electricity costs escalate by as much as 80 percent so this is a good idea. groSolar operates throughout the country and has a website at www.grosolar.com where people can find out how to work with them to install solar panels on their home anywhere in the U.S. This installation in Norwell is about a $15,000 project and considering the amount of equity it builds in the house, it is something worth considering. With assistnace from state programs, the cost can come down to half that figure, making it a very affordable investment for a homeowner.

Here s another great tip from BobVila.com. When photovoltaics or the conversion of solar energy to electric power came on the scene 30 years ago, it was so inefficient that few thought it could ever power American homes. But the technology has come a long way, and demand for PV systems in the U.S. is now growing at almost 25 percent per year. In sunny California, brownouts and energy crises have pushed the state to set an ambitious goal of putting photovoltaic systems on a million roofs by 2016. The cost of installation can be daunting for homeowners, but government incentives make them much more enticing. The federal government rebates $2,000 per system. In California, the state not only gives a property tax reduction for the cost of the system, it also rebates $2.50 for every system watt. So, a 4-kilowatt system that costs $36,000 only winds up costing the homeowner $24,000. In Florida, homeowners can get $4 per system watt, so the same system costs only $18,000. Add to that the value of the electricity generated by the system which, depending on your area, can be between $250 and $750 per year and photovoltaics start to make a lot more sense. As roof-mounted panels or even integrated into asphalt roof shingles, photovoltaic cells contain silicon wafers which react to sunlight by releasing free electrons. These electrons create direct electric current, or D/C power. The system s inverter switches the D/C to the alternating current, or A/C, that powers our homes. Household photovoltaic systems have become simpler and better adapted to mainstream use now that grid-tied net metering is easier and no battery backup is needed. Any electricity the system generates that s not used in the home gets sold directly back to the power company. In sunny areas, the larger 4-kilowatt systems available today can generate half or more of what the average household consumes. Even where it s not so sunny, photovoltaic systems have become so viable that many forward-thinking developers are pairing them with geothermal heat systems to market the new non-polluting, low-energy home. Find out more at BobVila.com: the ultimate home improvement web site! 2008 BobVila.com

This home will be about 50 percent more energy efficient than a typical Florida home. Bill Zoeller, a consulting architect with Mercedes, has changed specifications and products to make this home as efficient as possible. First, there are low-e insulated windows that will block about 70 percent of solar heat gain. The solid concrete walls are insulated with one inch of polyisocyanurate insulation board that is applied directly to the concrete walls. This insulation, which has the highest R-rating of any insulation on the market, will block the heat buildup during the day from reaching inside the home. In addition to Energy Star-rated appliances, the air conditioning ducts have been dropped to the attic floor and surrounded with insulation to reduce the efficiency challenge presented by running ducts through hot, Florida attic space. This technique was developed in California and is now part of their energy code. Dropping the ducts, wrapping them in insulating foam, and covering them in a polyurethane insulating foam improves efficiency and blocks condensation buildup in this humid climate. Lance Keeling, of BioBased Systems, explains that this foam insulation is soy-based but converted through chemical reaction to become completely inert to eliminate organic matter that could promote mold or mildew growth. This chemical is pressurized and sprayed with a hose to form a foam that sets up in moments. This foam provides a 4.8 R-value per inch but with a desired value of 6 from this part of the insulation, must be sprayed at a 1 1/2-inch thickness. This completely encloses the ducts to prevent any air loss and resulting moisture buildup. If a homeowner were to attempt covering ducts with commercial insulation, potential moisture buildup could be produced causing mold and moisture growth. The key with this technique is that it completely seals the ducts to prevent air loss and resulting moisture buildup. Zoeller and Keeling predict a savings of $100 per month in operating expenses due to the energy-efficient measures employed. Zoeller shows Bob the 14 SEER (seasonal energy efficiency ratio) heat pump air conditioning unit installed to cool the house. It is about 40 percent higher in efficiency than a traditional air conditioning unit. While initially more expensive, a smaller unit can be installed due to the high-efiiciency of the overall home.

Bob talks with Tim Cutler from TJ's Plumbing and Heating about the Viessmann boiler. The boiler is heating the domestic hot water, the radiant floor heating, and the hydro-air heating system. The hydro-air system has an air handler with a hot water coil. Warm air is dispersed throughout the building using this hydro-air system, which heats the existing, older portion of the house. Showers and hot water will be fed by a 79 gallon indirect, dual-coil, domestic hot-water tank. The bottom coil is fed by the solar heating system, which has 30 Viessmann evacuated tubes on the roof. The tubes have alcohol within them which has a low boiling point. When the alcohol in the tubes boils, it transfers the BTUs to a bulb, which transfers the heat to the lower coil for domestic hot water. A concrete cutter came in to cut an opening in the basement between the old portion of the home and the new addition. Bob talks with Bill Sloan from Viega North America about the radiant slab heating in the new addition. The radiant heating system uses PEX tubing. Viega manufactures the manifolds for this tubing and the copper tubing used to transfer hot water to the PEX tubing. ProPress joints that do not require any soldering are used for this sytem.

Bob visits the Global Solar factory in Tucson, Arizona, to see how they make their unique solar-electric (photovoltaic) devices. Neil Holstad, president of Global Solar, leads a tour of the plant. The factory itself includes many environmentally friendly features, including abundant day lighting, recycled brick fascia, graywater recycling, concrete containing fly ash, rammed-earth garden walls and energy efficient windows. They go inside the ultra-clean plant and see the unique flexible photovoltaic devices. The flexible material allows the devices to be used in many applications, such as the solar shingles used in the Habitat for Humanity project in Yonkers. Robert Wendt, Director of Technical Operations, shows Bob the materials used to make the solar cells and one of the manufacturing machines they invented for producing them.

Here s another great tip from BobVila.com. Before you add to your electric bill trying to keep cool this summer, add something to your windows instead. The first principle of passive cooling is to keep the heat from getting inside. Even though it seems like a wintertime activity, weatherstripping your windows and doors and caulking gaps can really make a difference in summer, too. There are lots of ways to shade your windows from the sun, and if they seem a little old-fashioned, it s because they worked even before there was air conditioning. Large roof overhangs and porches, awnings, shutters and louvers can all be seen on old southern homes. Awnings can actually reduce summer heat gain by up to three-quarters. And you can remove them in winter to let the sunlight in when you need it. Light-colored awnings are best because they deflect more heat. Solar screens are another option. Installed outdoors, they can cut heat gain in half, and you can still enjoy the view. Interior window treatments aren t quite as effective as the outdoor methods, but they re better than nothing. Densely woven fabric drapes, Venetian blinds or roller shades will control some heat gain just by keeping out direct sunlight. Again, lighter colors are most effective. If you re replacing your windows, ask about low-E glass. A low-E, or low-emissivity coating, depending on which surface of the window it s applied to, can keep heat where you want it and keep your costs down year-round. Find out more at BobVila.com: the ultimate home improvement web site! 2008 BobVila.com

Philips Products Marquee 9000 Series windows offer an innovative design comprised of 3 pieces of insulating glass, with two sealed airspaces filled with Argon gas. When combined with Low-E glass, these windows provide an energy efficiency increase of up to 90 percent over the average Low-E, Argon-filled vinyl window on the market. Solar heat gain coefficients are also improved by up to 40 percent with Philips' unique insulated vinyl windows. Philips' insulating glass package is up to 1 1/2 inches thick, compared with the 3/4 inch to 7/8 inch packages of other vinyl windows, and comes in a variety of styles and finishes.

A new concept in solar power, photovoltaic shingles, can help protect your home from the elements while generating pollution-free electricity.Wires from the photovoltaic cells on each shingle connect to a junction box. The current is sent to a battery for storage, and an inverter converts it to AC power. You can operate everything from a home computer to a security system with the electricity generated by these shingles.

Bob checks in on the Habitat for Humanity Blitz project in Yonkers, New York. He talks with Deane Evans of the Partnership for Advancing Technology in Housing (PATH) about the photovoltaic roof shingles. This new product from United Solar Systems, called the Solar Shingle, protects the house from the weather and generates electricity at the same time. Ren Anderson from the National Renewable Energy Laboratory (NREL) shows Bob how to nail the solar shingles on the roof just like conventional three-tab roofing. In this project, eight solar shingles are blended into the conventional fiberglass shingles to provide about 120 watts for charging battery-operated tools and toys in the shed below. Energy storage is provided by a 120 amp/hour battery. Ren hooks up the wires leading from the shingles to the other system components, which include a fuse, voltage regulator, and an inverter (which converts the direct current from the shingles into an alternating current that can be used by typical household appliances).