As fuel prices have risen, many people have grown interested in alternative sources of energy, such as solar energy for home use. Solar power is capable of reducing electricity and heating bills by significant amounts. If closely monitored, solar power could provide all of a family's electric and heating needs.
One of the most common uses of solar energy for home needs is heating water. A thermosiphon is a passive solar device that heats water; it uses no electricity or fuel and works automatically. The only cost involved is the initial purchase of equipment.
A thermosiphon consists of a flat, wide box with a glass cover. The glass allows visible light in, which is then absorbed by black tubing that carries water. Glass lets light in but will not let heat out, so this arrangement creates a miniature greenhouse effect. A thermosiphon can make its water quite hot. As the water in the tubes heats up, it rises up to a storage container, thereby forcing colder water out the bottom and back into the tubing.
The glass boxes of a thermosiphon can be built vertically onto one or more walls of the house. This configuration is used to provide heating for the house itself. As the tubes warm up, they warm the walls behind them as well, which in turn warms the rooms within.
Solar panels can also provide solar energy for home use. Like the thermosiphon, they are passive systems. The only cost involved is the initial cost of purchasing the equipment. Solar panels are made out of glass and a special semiconductor material. When light from the sun strikes this material, it knocks loose electrons, which form an electric current.
The average American household, for example, uses about 30 kilowatt-hours of electricity every day. A typical solar panel produces about 10 watts of electric power for every square foot of surface area. Large solar panels typically can provide about 150 watts of power. The use of ten such solar panels run just eight hours a day could produce half the electricity used by the average family.
Solar energy for home cooking is generally simple and inexpensive. A solar oven works much like a thermosiphon does. It is a glass-topped box with a black pot sitting inside it. The inside is coated with reflective foil and mirrors focus additional light into it. It is capable of cooking almost anything people regularly eat.
Though solar ovens can be slow, they typically need no maintenance. They use no power and cannot burn food. Many people claim that the slow cooking of solar ovens improves the taste of the food.