Solar thermal power is the extended form of solar energy or we can say that it’s the energy required for harnessing the solar energy.
How Solar Thermal Power works?
In this method energy from the sun is used to generate heat.Solar panels are used to gather heat from the sun so that heat is imprisoned and is used for water and space heating in buildings. These panels are located in such a way as to maximize absorption of heat from the sun during the day.The panels hold tubing through which water flow. This tubing is known as solar thermal collectors. In indirect method a non-hazardous anti freeze liquid is utilized instead of water.The sun warms the liquid and it shifts this heat to water held in a tank.
In solar thermal energy plants incoming radiation is trapped by large mirror fields they in turn concentrate the energy towards absorbers.The absorbers receive the concentrated radiation and transfers it thermally to the working medium. The heated fluid is operated as in power stations directly (in case steam or air is used as medium) or indirectly through a heat exchanging steam generator on the turbine unit which then drives the generator.
Different technologies for solar thermal power plants
Three different technologies for solar thermal power plants making useOf concentrating solar energy systems.
1 Parabolic troughs,
2 Central receivers (towers) and
3 Parabolic dishes.
1. Parabolic Trough
This system uses linear concentrators of parabolic shape which have highly efficient surfaces; it can be molded in angular movements towards the sun position and can focus the radiation onto a long line receiving absorber tube. The captivated energy is transferred by a working fluid, and the fluid is then piped to a conventional power conversion system.
2. Central Receivers
This system use heliostats to follow the sun by two axes mechanisms follow the elevation and azimuth angles with the function to reflect the sunlight from several heliostats (device used for tracking the movement of the sun) which are oriented around a tower and then focus it towards a central receiver which is at the top of the tower. This technology serves as an energy input to the power conversion system because it shift solar energy very efficiently by optical means of delivering highly concentrated sunlight to one central receiver unit.
3. Parabolic Dishes Systems
The reflectors focus sun rays on a dish-mounted receiver at its focal point. Within the receiver there is a medium for transferring the heat which uses the solar energy and shifts it to the power transformation setup, which could be mounted in one unit together with the receiver or at the ground. Dish collectors attain highest solar flux and the highest performance of all concentrator types with respect to peak solar concentration and of system efficiency due to its ideal optical configuration and two axis controls for tracking the sun. The dish technology is applicable to off-the-grid power generation, i.e. at remote places or at island situations.
• Solar thermal products and structure are a smart choice for businesses.
• The use of thermal products can accumulate our other natural resources and water for us.
• Thermal heating systems are very useful for businesses like hotels and restaurants.
• The annual cost of heating water can also be minimized by using thermal solar heating systems. For this reason many industries are replacing their energy sources from natural to solar thermal energy.
• This is a new technology and the government is supporting it and provides ease by reducing taxes on these products. The use of solar thermal products gives a corporate image of the commercial users.
• The systems are environment friendly and stop vast quantities of carbon dioxide, nitrous and sulfur dioxide from entering the atmosphere.
• A Solar Hot Water system provides 50 to 70% of water heating nearly free each year. In the months of summer, the system can in reality provide almost all your hot water needs and approximately 50% for the rest of year.
• Solar thermal systems will allow you to save money by improving your building energy rating lessening your energy bills.
• Net metering, is that the extra energy produced during the day by solar source will make your meter run in the opposite direction, so that at night you use the extra energy you have produced in the day time.
• Solar panels are low repairs and trustworthy systems.
• Dispatchable peaking electricity
• High conversion efficiencies
• Hybrid operation
• Dispatch able peeking electricity
• Hybrid operation
Future of Solar Thermal Power
For various commercial applications different technologies involved in the concentration are developing the new techniques and methods for the construction of the high flux solar system which would be of greater value as compared to the present ones. This high flux is efficiently used in commercial and business sectors. This type of solar thermal systems will certainly provide within the next decade a significant contribution to efficient and inexpensive, renewable and clean energy supply.