Solar energy technologies include heat energy water systems and electricity generation from the thermal and radiant energy of the sun.
Small solar energy electrical generation systems can provide electricity for homes, businesses, and remote power needs. Larger solar energy systems provide more electricity for contribution to the electric power system. Photovoltaic (PV) materials and devices convert sunlight, or radiant energy, into electrical energy, and PV cells are commonly known as solar cells. Photovoltaics can literally be translated as light-electricity.
PV systems are already an important part of our daily lives. Simple PV systems provide power for small consumer items such as calculators and wristwatches. More complicated systems provide power for communications satellites, water pumps, and the lights, appliances, and machines in some homes and workplaces. Many road and traffic signs also are now powered by PV. In many cases, PV power is the least expensive form of electricity for these tasks.
Photovoltaic systems can be very successful forms of renewable energy electrical generation for your home. Data such as how many kilowatts your household consumes in a month can help you determine what size solar panels (how many volts, amps) you would need. Talk to your local utility company or a reputable solar panel dealer for help in determining what is best for you
Solar Water Heaters
Solar water heaters, also called solar domestic hot water systems, use thermal solar energy and can be a cost-effective way to generate hot water for your home. They can be used in any climate, and the fuel they use—sunshine—is free.
Solar water heating systems include storage tanks and solar collectors. There are two types of solar water heating systems: active, which have circulating pumps and controls, and passive, which don't.
Most solar water heaters require a well-insulated storage tank. Solar storage tanks have an additional outlet and inlet connected to and from the collector. In two-tank systems, the solar water heater preheats water before it enters the conventional water heater. In one-tank systems, the back-up heater is combined with the solar storage in one tank.
The Three Types of Solar Collectors Used for Residential Applications
Glazed flat-plate collectors are insulated, weatherproofed boxes that contain a dark absorber plate under one or more glass or plastic (polymer) covers. Unglazed flat-plate collectors—typically used for solar pool heating have a dark absorber plate, made of metal or polymer, without a cover or enclosure.
Integral collector-storage systems
Also known as ICS or batch systems, they feature one or more black tanks or tubes in an insulated, glazed box. Cold water first passes through the solar collector, which preheats the water. The water then continues on to the conventional backup water heater, providing a reliable source of hot water. They should be installed only in mild-freeze climates because the outdoor pipes could freeze in severe, cold weather.
Evacuated-tube solar collectors
They feature parallel rows of transparent glass tubes. Each tube contains a glass outer tube and metal absorber tube attached to a fin. The fin's coating absorbs solar energy but inhibits radiative heat loss. These collectors are used more frequently for U.S. commercial applications.