Construction and Working of Solar Thermal Power Plant

What is a solar thermal power plant?

Most of the power plants in the world are thermal power plants. The main operation of the thermal power plant is to convert heat energy into electrical energy. The solar panel works by following the same things. The solar panel converts sun energy into electrical energy. It means we get electrical energy from the solar panel by converting heat energy. For this reason, the solar power plant is considered a thermal power plant. We know that solar energy is a renewable energy source and we don’t need money to get solar energy. In this case, we need a solar panel, solar inverter, batteries, connector, and some other small components. If we can install it successfully then we don’t need to pay the electricity bill monthly. So, if you install a solar panel at home then it can be the best choice to completely minimize the electricity bill. However, let’s see the construction and working of solar thermal power plant that we should know before using.  

Solar thermal power plant working principle

How solar thermal power plant works? Solar thermal power plant working principle is a bit different than a solar power plant. Basically, solar power plants generate electricity from solar energy into the electricity no turbine is required here. But you will require the battery to store energy, and an inverter to convert DC power to AC power. However, solar thermal power does not require a battery or inverter. It is because a solar thermal power plant generates AC electrical energy through a turbine and generator.

However, let’s see what is the main working process of the solar thermal power plant. Can you remember about magnifying glass or fire glass? It is a high-tempered glass if we hold this glass on a piece of paper along with the sunlight we will see that the paper burns. Solar thermal power plant works in this way. In this plant, electricity is generated by using the heat of the sun. Indeed different types of mirrors are used to reflect the sunlight and concentrate in a place.

solar thermal power plant working

So that it is possible to increase more heat in that concentrated area. Now, this heat is used to heat the water at a specific temperature. This steam water rushes and heats to the turbine then the steam turbine rotate and produce mechanical energy. This mechanical energy is supplied to the generator and the generator generates electricity. It is noted that there is a problem with it because the sun always moving. Whenever the sun goes east to west then the tempered glass does not move along with the sun. For this reason, such glass is placed depending on the sun’s direction.

PV cell working process

The PV cell working process is simple but PV cell construction is difficult and costly. Indeed photovoltaic cell (PV cell) consists of one or two layers of semiconductor materials, especially silicon materials. This PV unit consists of a special cell that produces electricity by converting sunlight into heat. Whenever the sunlight shines over the cells then an electric field is produced. It is noted that the stronger the sunshine, the more electricity is produced.  

Construction and working of solar thermal power plant

solar power plant construction

The construction and working of solar thermal power plant is almost the same as those of coal thermal power plant. The working process is a bit different from what we have referred to above. However, we will discuss here the construction of a solar thermal power plant. We know all thermal power stations have a bunch of equipment for any specific operation. Many crucial components are installed in solar thermal power stations but we are referring to some of them.

  • Flat plate solar collector
  • Hot water tank
  • Heat exchanger
  • Steam turbine
  • Condenser
  • Alternator or generator
  • Circulating pump

Flat plate solar collector

The flat plate solar collector is a solar thermal collector that has a flat plate absorber. It is the most common type of solar thermal collector that is used worldwide. A flat plate solar collector is typically made up of two sheets of metal, one being the absorber and the other being the reflector. The absorber has a glass layer or plastic on it, which prevents sunlight from being absorbed by the metal. The reflector is usually made of polished aluminum, which reflects light back onto the absorber to increase its efficiency. For this reason, it is used with a photovoltaic system to generate electricity and provide hot water simultaneously.

Hot water tank

The hot water tank is used to store hot water and it is used in the solar thermal power plant. It has a large storage capacity and can provide enough hot water. It is usually made of steel or copper and has a set of pipes attached to it. Whenever cold water travels through this pipe the cold water then heats up and becomes hot water and produces steam. This steam rushes to the steam turbine and the turbine starts rotating. An alternator also rotates with the turbine. It is because the turbine and alternator both are coupled. The steam turbine gives mechanical energy and the alternator converts mechanical energy into electrical energy and we get output electrical energy.

Heat exchanger

The heat exchanger is a device that is used to transfer heat from one stage to another. All thermal power plant requires a heat exchanger which is a very crucial device to transfer heat from one stage to another. Basically, heat exchangers transfer thermal energy but sometimes heat exchangers may fail due to some common reasons, such as air filter blocking, dirtiness, and others. Basically, it is located near the combustion chamber.   

Steam turbine

The steam turbine is the common device for the thermal power plant. The turbine is used for all power plants except the diesel power plant. It is because the diesel power plant working principle is different than some other power stations. Indeed any type of steam turbine can be used in the solar thermal plant based on the generation capacity. The solar thermal plant is also called a solar steam power plant because steam is the injected fuel to generate mechanical energy from the turbine.


A condenser is a device that is used in the solar thermal power system to condense steam. Steam heats to the turbine to rotate and some exhausted steam comes to the condenser. The condenser condenses the regenerative steam into liquid and sends it to the heat exchanger again to be steam to use again. This process goes on until stop solar thermal power production

Alternator or generator

The alternator is an AC generator that converts mechanical energy into electrical energy. An alternator or AC generator is an indispensable machine for all power plants. The alternator is used in the solar thermal power station to generate electricity. In this case, a steam turbine gives mechanical energy by converting steam energy and an alternator takes this mechanical energy and generates electricity through a special process. 

Circulating pump

A circulating pump is an important device for the steam power plant. It delivers cold water through the condenser from a freshwater source that is exhausted from the turbine. The circulating pump is mainly located in the wet pits. Indeed it transfers cooling water to the condenser. In this case, steam waste can be reduced and steam can be used again for the turbine.   

We have been told that the solar thermal power generation process is almost the same as coal power plants but they have a bit different. The solar thermal power plant cannot be built at any location. Where we get sufficient sunlight within a day choose such a location. It is because sunlight is the main thing to generate electricity. However, there are some crucial factors that you should know  

Choose location

 Location is a crucial factor for all power plants. If it becomes a coal-fired power plant then you must decide on that coal handling arrangement, rail line, water transplant, etc. but solar thermal power plants don’t require rail and coal handling arrangement plant. But a large amount of area is required to construct this power station compare to the coal thermal power station. It is true that how much power generation you are thinking about, how much radiation glass you want to be placed, and others. Your space will depend on such requirements. You must remember that choose a location where there is no big tree, no shadow, and a sunny area. So, your plant gets sunlight during the day.

Area limitation

The concentrating solar thermal power (CSP) plant requires a large space. Because you need a large number of solar mirror installations. For example, if your parabolic solar thermal electric energy generation becomes 50 MW then you need 200 hectares of flat land which corresponds to the size of 280 football pitches. If you have a 100 MW generation capacity then you have to enlarge the place. So, the solar thermal power station area depends on you and your generation capacity.

Natural phenomenon

Natural phenomenon means storms and earthquakes that have a direct impact on the energy system cost. For this reason, design a solar thermal power plant and decide on such places where there is no chance for such impact. It is because solar plant is very costly than other power plants. Some other decisive location factors are favorable financing and low investment risk conditions for investors.

What are the types of solar thermal power plant?

Electricity can be generated in two ways. First of all solar power plants. In this case, a large number of the solar panel is installed in a place where sunlight is available during the day. How many solar panels you need to install it depending on how much power you want to generate. In this case, you need many PV panels, batteries, and inverters to get output AC power. If sunlight shines over the PV panel then the electric field is produced and we get DC electricity.

types of solar thermal power plant

This DC power is converted into AC with help of an inverter. This is a simple process for the solar power plant. On the other hand, solar thermal power stations. The solar thermal power station working process is the same as the coal power plant that we have referred to above. It is noted that a solar thermal power plant does not require a battery and inverter. It generates AC energy and it can be stepped up by using a step up transformer. There are three main types of the solar thermal power plants, such as

  • Solar tower power plant
  • Parabolic trough power plants
  • Linear fresnel reflector power plant

On the other hand solar thermal power plant types can be divided into three, such as

  • low temperature solar thermal power plant
  • medium temperature solar thermal power plant
  • high temperature solar thermal power plant

Solar thermal power plant efficiency

The solar thermal power plant is a popular option for generating electrical energy. The solar thermal power plant is more efficient than photovoltaic panels and solar steam power plants can also generate electricity even when the sun is not shining. Solar thermal power plants use mirrors to focus sunlight in a fluid that heats up and produces steam to turn a turbine. The fluid must be kept at high pressure for the heat to be retained, but this also increases the efficiency of the plant.

thermal plant efficiency-

Basically, a single solar dish produces as much as 25KW of electricity with a conversion efficiency of 31.25% whereas a solar parabolic trough plant is built with 20% efficiency. Solar thermal power efficiency depends on some factors, such as field efficiency, steam cycle efficiency, collector efficiency, etc. collector efficiency depends on the sunlight and temperature absorbed in the tube that reaches up to 75% and field losses of less than 10%. However, the overall consideration of the solar thermal electric power plant’s annual efficiency is about 15% and steam cycle efficiency is about 35%. So steam turbine power plant efficiency is 35% and solar thermal efficiency of over 20% is possible.

How to calculate the efficiency of solar panel?

Efficiency is obtained if we divide the output power by the input power and multiply by 100 then we get efficiency (output/input * 100). We know that efficiency means the output power of a plant or device. Efficiency is a crucial thing for all sectors and all devices. If toy would like to calculate efficiency of solar panel then you can follow simple rules and see how to calculate solar panel efficiency.

We have shown solar panel efficiency calculation by a simple formula. Solar panel is costly, that’s why you should know solar PV efficiency calculation before you buy. You must know how many solar panels you need for your installation. If you know the efficiency calculation then you can easily decide how many solar panels you need to install for your specific load. It is noted that you may follow the best direction to install solar panel.

Final thought

The thermal solar farm or solar thermal power plant is used to generate bulk electricity. In this case, many glass-type solar panels are used to concentrate heat in a place to heat the water and produce steam to run the steam turbine. However, we have shown the construction and working of solar thermal power plant that may give you a better idea of the solar thermal power station. We hope this information may give you better knowledge and stay with openread to get innovative things.

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