A Brief Guide to Concentrated Solar Thermal (CST) Solutions

The total amount of energy produced by the sunlight reaching the earth is twice that of all the other renewable sources. Usage of Solar Energy helps us reduce the usage of other non-renewable energy sources and thus reduces the carbon footprint.

There are various methods to convert solar energy into electricity. The most common ways of producing solar energy are photovoltaics and through solar thermal or a combination of both.

In this article, we take a look at solar electricity in particular about the Concentrated Solar Thermal solution (CST) using solar dish and the application of CST. We also take a look at how Solar Thermal power differs from solar photovoltaics.

Sun’s rays which reaches earth contains heat and light which can be harnessed using various active and passive solar technologies. Active Solar techniques uses the sun’s irradiance or radiation with the help of external devices like Photovoltaics, solar thermal systems, and other types of equipment to convert solar energy into electricity, whereas passive solar technologies don’t use any external devices and use sun’s heat to retain and distribute heat inside buildings using windows and other fenestrations.

Mirrors and trackers are used to concentrate a large area of sunlight to a small area to generate a lot of heat by the Concentrated Solar Power system. The heat generated is converted into mechanical energy by turbines and then converted into electricity using electric generators.

There is different Concentrated Solar Thermal system such as Linear Fresnel Reflector, solar towers, parabolic troughs and parabolic trays. Each one of these systems can produce high temperatures and their efficiencies can vary with the way they can track sun and focus the sun’s rays to convert to heat.

The dish shape reflector concentrates sun’s radiations to a receiver at a central focal point above the dish. The receiver moves in sync with the dish as it tracks the sunlight.

The sunlight is collected by the receiver from the parabolic solar concentrator with high intensity with temperatures rising upto 1000 degree Celsius. The heat formed can be used to generate power from the steam when it is fed to the electricity production system.

This system is the most efficient of all the systems offering the highest solar of electric conversion with the least loss of sunlight

• Both of these systems are used to convert sunlight to electricity. The Solar photovoltaics does it direct conversion whereas Solar thermal is an indirect conversion.
• Solar photo voltaic capture the sunlight and the photo voltaic panels consisting of the solar cells convert the sunlight to electricity directly.
• Solar thermal concentrates the light from the sun to create heat and that heat is used to run a heat engine, which turns a generator to make electricity.
• In some of the systems there is the usage of a working fluids like water, oil, salts, air, nitrogen, helium etc. that gets heated up by the concentrated sunlight which works in association with heat exchangers and is circulated through the system.

• Renewable - non polluting, reduced carbon footprint
• Easy to integrate with other heat generation systems.
• These systems are highly efficient and scalable to meet large energy demands.
• Easily storable to match the demand.
• Flexibility- Provides a flexible source of energy that can easily be be dispatched due to accessible storage.

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