Home Eco Friend Popular The Good, the bad and the ugly: Solar thermal energy

The Good, the bad and the ugly: Solar thermal energy

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Solar thermal energy

Directly or indirectly, we derive most of our energy from the sun. It would be apt to call it the powerhouse of the solar system.  In fact, if we make efforts to concentrate this energy and utilize it, we might easily replace all the non-renewable energy sources. In addition, by using technologies like space mirrors, solar energy might even help us in regulating climate and fighting global warming. However, this and other similar sustainability concepts are unfeasible now. Right now, we can only use concepts like solar thermal energy as these are available. So, here’s all you might want to know about it.

Solar Thermal Energy

Solar Thermal Power

The technology for harnessing solar energy to generate heat or thermal energy is called solar thermal energy (STE). The US Energy Information Administration has classified the solar thermal collectors as low, medium, or high-temperature collectors. Low-temperature collectors are used to heating swimming pools. However, medium-temperature collectors can be used to heat water or air for private or commercial purposes.

Both these collectors are flat plates. The most important and effective are the high-temperature collectors, which use sunlight to generate electricity. Mirrors or lenses are used to concentrate sunlight which then produces electric power production. STE should not be confused with photovoltaic, which are also used to harness sunlight to generate electricity. The basic difference between STE and photovoltaic is that the former is more efficient than the latter. Currently, we are able to generate around 600 megawatts of solar thermal power. It is believed that the STE can be used to generate as much as 14,000 megawatts.

The Good

The good about solar thermal energy

1. Water heating and home heating at a low price

The use of sun’s energy to heat water can reduce the consumption of electricity to a large extent. Moreover, these days many homes are using solar hot water heaters. These can work in any climate and require very little maintenance.

2. Unlimited source of energy

The solar energy is unlimited. In addition, unlike fossil fuels, we need not worry that the sun’s thermal energy will end one day.

3. Environmentally friendly

One of the major advantages of the solar thermal power plants is that they are completely emission free. We can install these plants on undeveloped, unproductive land and the materials used in building this plant can be procured by using recyclable glass, steel, and concrete.

4. More efficient than photovoltaic thermal energy

The photovoltaic thermal energy which is currently in use more than thermal power plants is not as efficient as the thermal power plants. Experts maintained that we can use the thermal power plants to generate huge amount of energy.

Can this be better?

We can produce considerable amount of solar thermal energy using just the sun and materials that are capable of trapping, storing and then dispersing the energy of the sun. Thermal energy is heat energy and it is different from the energy generated by photovoltaic solar panels. Researchers believe that the proper use of this energy can end our dependence on electric heating systems and will help us protect the environment and conserve renewable sources of energy. The STE has the potential to emerge as the future of power supply across the globe. The STE is inexpensive and unlimited, which makes it a highly desirable option in future.

The bad

The bad about solar thermal energy

1. The reliability of solar energy

Solar energy is highly unreliable and if we want to use solar thermal collectors to meet our energy demand, we need consistent sunlight, which is not possible in all the regions of the world and round the year. Suring rainy season, the amount of sunlight decreases considerably.

2. Solar energy plants need large installation spaces

We know that the sunlight do not concentrate at any one spot on earth and in order to harness the sunlight we need to set up solar power plants in large areas so that the collectors can trap maximum amount of thermal energy. If we want to install a solar energy plant that can provide electricity to a small community of homes, then we will have to install the plant in few acres of land, which is nearly possible in densely populated cities and towns.

Can this be avoided?

The rising cost of fuels and depleting reserves of renewable energy has forced us to think of tapping the alternative sources of energy of meet our energy demands. When we talk about alternative sources of energy, the first name which comes to our mind is the sun. Experts maintained that solar energy has the potential to meet a lot of our energy demands. Having said that, it is not easy to harness the solar energy and like everything else solar energy has its weaknesses as well, which are mentioned above. These days several countries are installing solar power plants to harness energy but we still need to cover a long way before we can start depending on solar energy to meet our daily energy needs.

The ugly

The ugly thing about solar thermal power

1. Solar Energy is expensive

The installation of a solar power plant requires a considerable amount of money. We need to build and install a solar power plant in order to use it as a power source and this is expensive.

Why are we so critical?

The carbon footprint of a product is determined by taking into account two things: the amount of carbon produced by the product and the amount of energy which is required to manufacture the product. The factories which manufacture solar collectors use fossil fuels, which means that though the energy generated by using these solar collectors are emission-free, the process which is used to manufacture these collectors are not emission-free. We need to find methods using which we can manufacture solar collectors without harming the environment.

Example: Australia’s largest solar-thermal tower system

braytoncyclesolar 1

Eco Factor: Solar thermal tower power plant generates electricity without using water.

Australia’s national science agency, the Commonwealth Scientific and Industrial Research Organisation (CSIRO), has developed a technology that requires only sunlight and air to generate electricity in areas facing acute water shortages. The solar Brayton Cycle project replaces the use of concentrated sun rays to heat water into high-pressure steam to drive a turbine with solar energy to create a solar thermal field.

The technology focuses the sun’s rays projected onto a field of mirrors knows as heliostats onto a 30-meter (98 ft) high solar tower to heat compressed air, which subsequently expands to through a 200kW turbine to generate electricity. Moreover, the cost-effective heliostats created for commercial use consist of a lightweight frame with a simple design. CSIRO has already begun installing the 450 heliostats at the National Solar Energy Centre in Newcastle, New South Wales. Once installed, it would become Australia’s largest solar-thermal tower system able to generate temperatures of up to 1,000 degrees Celsius.


Sun’s energy is used by solar thermal energy to heat the thermal applications. There are three kinds of temperature collectors, low, medium and high. There is no denying the fact that the STE has many positive aspects bit more work is needed to make the STE more cost-effective and environment-friendly.

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