Solar energy is a form of renewable energy. Renewable energy is the energy which is generated by use of natural resources which are naturally replenished. Humans have used solar energy from ancient times, to satisfy his various needs. A sunray emitted from the Sun takes 9 minutes to reach the Earth.Solar energy technologies can provide electricity generation by photovoltaic means. But there are other uses in which this energy form can be harnessed. It can also be used in disinfection and distillation of drinking water, space heating and cooling in active and passive solar buildings, day lighting, hot water and thermal energy for cooking.
In few countries, solar powered car are in use but only on experimental purposes. Development of solar powered car has been an engineering goal since humans understood the importance of solar energy. The World Solar Challenge, a biannual solar powered car race, is organized, where teams compete over 3021 kilometers. Some vehicles use solar panels as a auxiliary power for air conditioning and thus reducing fuel consumption.
A black balloon that is filled with ordinary air is called a solar balloon. As the sunlight shines, the air inside the balloon is heated and it expands causing an upward buoyancy force. Some solar balloons are very large, enough large for human flight but the usage is limited to toy market industry.
Nowadays solar lantern has also gained popularity. A solar lantern contains three main parts- the photovoltaic panel, battery and the lamp. This is how it operates. Solar energy is converted to electrical energy by PV panel and is stored in sealed maintenance free battery, and lamp glows when the battery is charged. After a single charge the lamp can glow upto 4-5 hours.
Solar Water Heater:
A solar water heater uses the Sun’s light to make hot water. The monthly electricity bill also reduces by using this solar water heater. When installed and used properly solar water heaters are more economical compared to heating water with electricity.
Solar cooker is used to cook food in Sunlight for 10-15 persons. A solar cooker is made up of single reflector or by joining smaller pieces of reflectors, fixed to a frame, when exposed to Sun, a point focus will be formed for cooking the food. It is made up of bright anodized aluminum sheets. By using this you can save your fuel or gas, whatever you use.
Solar Water Pumping System:
Solar water pumping system, is a system operating on power generated using solar PV system. The power which is generated is used by the DC pumpset (motor) for lifting water from well, bore or water reservoir for irrigation or for drinking purpose.
Solar Water Distillation:
Solar distillation is used to make brackish water or saline water potable. The first plant was constructed in 1872 in Chilean town of as Salinas. There are different still designs like vertical, conical, inverted absorber, single slope, double slope, multi wick and multiple effects. These still designs operate in active, passive or hybrid mode. Another technique called solar water disinfection is also used; in this technique PET bottles are exposed to Sunlight for several hours. Exposure time can be 10 hours or can be 2 days depending on the weather conditions. WHO has also recommended SODIS. More than 2 million people use SODIS in developing countries.