The concentrated heat is used as a source of heat for a conventional power plant. The wide range of concentrating technologies is now available. The parabolic trough is the most developed. Other structures made include the Stirling dish, the linear Fresnel reflector and the solar power tower. Several techniques are used to locate the sun and concentrate light. Once the solar energy runs out, electricity coming from the utility will take over. The flow of solar energy electricity is measured via a utility meter that spins forward and backward. The meter will move backward if more energy is produced than needed and the meter will move forward when extra power is required from the utility company. Water is pumped to a tank after heating. Indirect systems use heat transfer fluid. The fluid is heated in solar collectors, then pumped to a storage tank. This is also known as a closed-loop system. The Third Type Active solar pool heating involves the use of pumps to properly circulate the water in the pool via solar collectors to heat and then return to the pool. Solar Energy Today Right now, solar energy is being used for a number of reasons. It is being widely used for certain purposes, such as providing your home with an alternative source for energy and electricity, thereby allowing you to greatly reduce the cost of your energy and electric consumption by a considerable margin. These were more cost-effective and less fragile, with about 20% efficiency. More Technologies There are several technologies now, including a minimum of 14 photovoltaic cell types, like polycrystalline silicon, thin film, monocrystalline silicon and amorphous cells. Concentrating solar power also appeared in several types. The design of the solar vehicle is limited by the energy amount placed into the car. Majority of solar cars were made with the objective of solar car races. A few exceptions include solar-powered cars and utility vehicles. Solar cars are usually fitted with the gauges similar to conventional cars. The driver has to watch the gauges closely to see potential problems and keep the car running very smoothly.