Solar power is most commonly known for using the sun’s energy to produce electricity. The sun’s energy, however, has been used for far longer to heat water and homes than for generating electricity.
Solar Power for Water Heating
The hot water heating system consists of a holding tank, a solar collector and equipment to circulate the water. The hot water heating system can either be a direct system or an indirect one.
In the direct system, the water that flows through the collector is heated. In the indirect system, the fluid heated in the collector is passed through a heat exchanger in the holding tank, thereby heating the potable water in the tank. The holding tank merely holds the water that has been heated, or is being heated.
The solar collector, which is usually located on the roof heats the water. Normally, the collector is a thin, rectangular box, which has a series of pipes running through it, painted black for maximum heat absorption. The water that runs through these black pipes gets heated.
For water circulation, there is either a low-powered pump, or it’s achieved through convection, where the hot water rises and the cold water sinks. To achieve circulation through convection, the holding tank is placed above the collector, so the water rises into the holding tank, as it heats up and the cold water sinks down to be heated. A low-powered pump can also be used to circulate the water.
Heating your water for domestic purposes through solar power makes sense, as it is available all year round. This saves you utility cost on water heating, which makes up an average of 40 percent of the total household utility cost.
Solar Power for Building Heating
The sun, naturally, heats up buildings. It can also be done by special building design, or by the use of solar collectors. Passive solar heating occurs in every structure, but can be maximized when a building is specially designed to capture the sun’s heat. It involves the use of special materials in the floors and walls of the building to store the sun’s heat.
The building is designed with as many windows as possible facing in the sun’s direction. This means that in the northern hemisphere the windows are south facing, and in the southern hemisphere, north facing.
Where a solar collector is used, the air is passed through it to heat it, then the heated air is passed into the house. The solar collector is also used to heat a liquid, which is then passed through the pipes, which are often laid under the floor of the house, heating it. The result: comfortable heat, free and natural.
Written By: J.R. Ferrara
