Use of home solar cells is increasing in U.S.
Q. I see television shows about using solar cell panels to generate clean electricity. Can these solar cell systems also be used on houses? Can I use one of these systems and still stay connected to my utility company?
A. With recent high energy costs and emphasis by the new environmentally conscious administration in Washington, D.C., there is tremendous interest in using solar cells (called photovoltaics or PV) to generate electricity.
PV systems can be used on residential houses and have been for decades. In addition to the above mentioned reasons for the growth in interest, the efficiency of PV systems has been increasing and the cost has been decreasing.
In the past, PV systems were typically installed on remote houses that had no access to utility grid electricity or their electricity usage was extremely low. Today, many of the solar companies that produce PV products make systems specifically designed for houses that are still connected to the utility grid. These are called "grid-tied" systems.
The advantage of a grid-tied system is it eliminates the need for battery storage for times when the sun is not shining. At night or during cloudy weather when your PV system is not producing enough electricity to meet your family's needs, your house draws electric power from the utility grid.
If you install a large PV system, during a sunny afternoon when everybody is at work or school and the electricity usage is minimal, it will produce more electricity than your house is consuming. Check with your state energy office and your local utility company to see if they offer net-metering. With net-metering, the utility company buys the excess electricity from you. In effect, your electric meter runs in reverse.
The size of PV system you will need for your house depends upon your region of the country and your electricity needs. Obviously, if you live in Arizona or Colorado with many bright sunny days, a smaller system will generate as much electricity as a larger one in cloudy Seattle or Cincinnati. A three- to four-kilowatt output system is common for a house. You should typically figure on about $8 to $10 installed cost per watt.
PV panels consist of an array of solar cells made from either crystalline silicone wafers or thin film amorphous silicone. The wafer design is more efficient, but it also costs more so the end cost per watt is similar.
The PV panels can be mounted above the roof, on supports on the ground or on supports that track the sun during the day. Some of the newest designs for houses are designed to be used as the shingles or roof material itself. Since there are no moving parts, they have a very long life.
The following companies offer photovoltaic systems: Kyocera Solar, (800) 223-9580, www.kyocerasolar.com; Northern AZ Wind & Sun, (800) 383-0195, www.windsun.com; Schott Solar, (888) 457-6527, www.us.schott.com; Solar World Industries, (800) 272-6765, www.solarworld-usa.com; and Zomeworks, (800) 279-6342, www.zomeworks.com.
Q. We have a newer low-flow toilet. The toilet tank sweats badly during winter, but not during the summer. I thought it is usually reversed. What would cause the tank to sweat and how can I stop it?
A. You are correct that toilet tanks typically sweat during the summer because the indoor air is warmer and holds more moisture. In your case, the incoming water must be very cold and does not get a chance to warm up.
A tightfitting insulation jacket for the toilet tank will keep the room air from contacting it and this should reduce the sweating. Also, lower the indoor humidity in the bathroom by running the vent fan when you bathe.
• Write to James Dulley at 6906 Royalgreen Drive, Cincinnati, OH 45244 or visit dulley.com.