Different Ways to use Solar Energy –
What is Solar Energy ? What are the different ways to use Solar Energy ?
Solar Energy is the radiation that is obtained from the sun’s heat. There are many different ways to use solar energy. The definition of solar energy can be viewed by the link mentioned below.
Solar energy has numerous uses and some of the ways are mentioned below –
Solar Energy can be used for Solar Thermal applications, Photovoltaic applications, Social applications, Industrial applications and Consumer applications.
Water Heating –
Solar Energy can be used for heating water. The cold water can be heated easily and may sometimes also used for purification of water. This can also be made a household application. Solar Water Heating is one of the most attractive solar thermal applications from an economic stand point.
The main components of the water heating system are the liquid flat plate collector and the storage tank. The storage tank is located above the level of collector. As water in the collector is heated by solar energy, it flows automatically to the top of the water tank. It is replaced by cold water from the bottom of the tank. Hot water for use is withdrawn from the top of the tank.
Whenever this is done, cold water automatically enters at the bottom. An auxiliary heating system is sometimes provided for the use on cloudy or rainy days. When large – amount of hot water is required, a natural circulation system is not suitable. Large arrays if flat plate collectors are then used and forced circulation is maintained with a water pump.
Space Heating –
A Space Heating system consists of water heated in the solar collector and stored in the tank. Let the solar collector be A and the Tank be B. The energy is transferred to the air circulating in the house by means of water to the air heat exchange. Let the air heat exchange be E. Let the two pumps provided be C which provide forced circulation between the collectors and tank, and also between the tank and the heat exchanger. Provision is also made for providing auxiliary heat. An alternative approach to space heating is to heat the air directly in the collector.
A space heating system is illustrated in the figure above. Water is heated in the solar collector named as A and is stored in the tank B. Energy is transformed to the air circulating in the home by means of water to air heat exchange E. The two pumps C provide forced circulation between the collectors and the tank, and between the tank and heat exchangers. Provision is also made for adding auxiliary heat.An alternative approach to space heating is to heat air directly. The heat is then stored in a tank packed with rock, gravel or pebbles.
In contrast to the above methods, which are often called active methods, space heating gives a fair degree of comfort by adopting passive methods. A passive method is one in which thermal energy flows through a living space by natural means without the help of a mechanical device like a pump or a blower. A diagram of such a system is designed by Professor Trombe.
When the wall of the house is double glazed, with its behind a thick black, concrete wall which absorbs the sun’s radiation and serves as a thermal storage vents. This can be kept open or closed and are provided near the top and the bottom of the storage well.
During the day, both the vents A and B are kept open. The air between the inner glazing and the wall gets heated and flows into the living space through the top vent. Simultaneously, the cooler air from the room is pulled out of the living space through the bottom vent. Thus, a natural circulation path is set up. Some energy transfer to the living space also takes place by radiation from the inner surface of the storage well. During the night, both the vents are closed and the energy transfer takes place only by the radiation.
The Trombe wall design can also provide summer ventilation by using the vents C and D near the top of the glazing and on the north facing wall. On a hot summer day, vents B, C and D would be kept open, while vent A would be kept closed. the heated air between the glazing and the wall would then flow out through the vent C, drawing the air from the living space to replace it. This will in turn would cause air to be pulled in from outside through the vent D. The vent D should be located such that the air pulled in through it comes from a shaded and cool area. It should be noted that the overhanging roof prevents direct radiation from falling on the glazing during summer.
Solar Drying –
One of the traditional uses of solar energy has been sued for drying of agricultural products. The drying process removes moisture and helps in the preservation of the product. Traditionally, drying is done on open ground. The disadvantage associated with thus are that the process is slow and that the insects and dust get mixed with the product. The use of dryers will help to eliminate these disadvantages. Drying can then be done faster and in a controlled fashion. In addition, a very better quality product is obtained.
Solar Driers are the devices used for the removal of moisture from the interior of the material to the surface and then to remove the moisture from the surface of the drying material. There are several ways of preserving food, but drying is a traditional method for preserving food. It also helps in easy transport since the dried food becomes lighter because of the moisture loss. Drying of seeds prevents germination and growth of fungi and bacteria.
Space Cooling and Refrigeration –
Space Cooling and Refrigeration can also be obtained by solar energy. This is the same as Space heating but in opposite direction. This is the process done same as in the refrigeration.
Solar Distillation –
Solar Distillation is the use of sun’s heat to evaporate the water and again collect the condensate in the same closed system. It is so useful that it can even turn the salt water to drinking water. Solar distillation is even used in many areas and is very helpful solar energy application.
These are the different ways to use solar energy as thermal heat.
Industrial Applications –
There are many different ways to solar energy. Solar energy is used in many industrial applications like in Telecommunication, Navigational ads, Remote aircraft beacons, Alarm systems, Defence equipments, Emergency equipments and Cathodic protection.
Social Applications –
Solar energy is used in many social applications such as providing electric power to remote villages, lights in garden, solar street lamps and much more.
Consumer Applications –
Solar energy is used in many consumer applications like pocket calculators, watches, clocks, garden lights, radios, electric fences, toys and much more.
These are the different ways to use solar energy.