Exploiting solar energy can meet power demand.


Byline: Syed Fazl-E-Haider

Renewable energy experts estimate that a solar home costs Rs.100,000 but a solar energy system can be installed with one-time expenditure and the system needs no additional expenditure for years. From economic point of view, the solar thermal power plants will reduce the dependency on fossil fuels in remote areas. The operation and maintenance cost is nominal, compared to conventional power plants. Moreover, these plants will also avoid the risk of future electricity cost escalation. They are not only emissions-free in nature, but are ideally suited to reduce green house gases and other pollutants.

Solar energy is the most reliable and abundantly available renewable source. Solar thermal power plants produce electricity in much the same way as conventional power station. The difference is that they obtain their energy input by concentrating solar radiation and converting it to high temperature steam or gas to drive a turbine or engine. Solar power plants can simultaneously produce electricity, provide cooling by means of an absorption chiller, generate industrial processing steam and produce drinking water with a sea water desalination plant.

The solar thermal plants for power generation may be set up in Pakistan, which is rich in renewable energy (RE) resources. The country's solar energy potential needs to be exploited fully in view of the growing energy demand. Generally, solar thermal power plants use parabolic trough and dish sterling technologies. Solar parabolic trough consists of curved mirrors, which form troughs that focus the sun's energy at 30-60 times its normal intensity on a pipe. A fluid is circulated through the pipes, which is then used to generate stream, which powers a turbine that drives an electric generator. On the other hand, the dish sterling concentrating solar power unit uses a mirror in the shape of a dish to collect and concentrate the sun's energy onto a small area where a receiver is located. The receiver transfers the solar energy to a sterling cycle engine that converts it into power.

The National Institute of Silicon Technology (NIST) has developed mathematical models that give the solar insulation values at any time on any surface inclination. Need is to promote the use of solar energy and to strengthen its technology base so as to allow this source of alternative energy achieve its full potential and contribute towards meeting the provincial electricity needs. There is a need to...

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