What is the solar thermal power generation process?
The solar thermal electricity generation process is like coal or some other thermal power plant. In this case, solar radiation is used to generate heat, and steam is created to drive the steam turbine. This steam runs through the steel pipe with high pressure. This high-pressure steam hits the steam turbine to rotate and the turbine generates mechanical energy and mechanical energy is converted into electrical energy. It is noted that a solar thermal power plant is also called a solar steam power plant. It is because steam is used to produce electricity. Let’s see the construction and working of the solar thermal power plant. However, let’s discuss solar thermal power plant types and which types of solar thermal power plants is used more to generate electricity.
What are the types of solar thermal power plants?
The solar thermal electric power plant is a type of electricity generation power station. Solar energy is the main energy to generate electricity. However, there are three main types of solar thermal power stations based on temperature.
- Low-temperature solar thermal power plant
- Medium-temperature solar thermal power plant
- High-temperature solar thermal power plant
On the other hand, if we think about the solar thermal power station then we get five main types of solar power stations, such as
- Parabolic trough solar thermal power plant
- Central receiver power plant
- Solar chimney power plant
- Dish sterling system
- Solar Pond power plant
1. Low-temperature solar power plant
The low-temperature solar power plant is a type of solar thermal power plant. It is used to generate low power and low hot water temperature compared to some other thermal power stations. The hot water temperature is considered as 80 to 1000C and such hot water is stored in a better-insulated thermal insulated tank. The low-temperature solar power plant uses flat plate collectors and works on the Rankine cycle.
The water temperature becomes increased due to the high heat solar energy and this water runs through a flat plate collector. It is noted that the working fluid has a low boiling point which is why we get steam at 900C. This steam hits the steam and steam helps to run the alternator and we get electrical energy from the alternator output.
2. Medium-temperature solar power plant
Medium-temperature solar power plant refers to a type of solar thermal power plant. This power station uses mirrors to focus sunlight onto a fluid-filled receiver, which heats a working fluid (water) to generate steam. The concentrating collectors are used in medium solar thermal power stations with high temperatures (250 to 4000C). The steam runs to drive a turbine, and the turbine is coupled with the turbine which generates electricity by converting mechanical energy into electrical energy.
3. High-temperature solar power plant
A high-temperature solar thermal power plant is a type of solar power generation station. Thus types of power plants use mirrors or lenses to concentrate the solar energy to generate heat energy. This heat energy is used to produce electricity. High-temperature solar thermal power plants, also known as concentrated solar power (CSP) plants, use mirror solar panels to concentrate the solar energy to produce heat.
Concentrated solar power (CSP) plants are typically larger and more expensive to build and maintain. The heat is typically used to boil water, which generates steam that hits the turbine and the turbine rotates and the alternator also rotates with the turbine then generates electricity. High-temperature solar thermal power plants can generate electricity at very high temperatures (600 to 700 degrees Celsius), which makes them more efficient than traditional solar power plants.
1. Parabolic Trough Solar Thermal Power Plant
The Parabolic Trough Solar Thermal Power Plant delineates one of the most important renewable energy. It has been built with many successful technologies throughout the decades. The parabolic troughs are within the cheap rate and a better option for the solar electric powers that are widely accessible presently and it can easily lessen the costs.
The nine parabolic trough plants contain 350 megawatts of electronic generation which have been operating daily within California Mojave Dessert for 18 years. These plants can generate extra electricity to fulfill the requirements of residential members of the city which has 350,000 people.
They have very successful availabilities which state that during the solar hours, you can receive 100% availability and they have some reliable powers to meet the peak electric loads of California. These powers are being stored to meet the California Energy crisis from 2000 to 2001. Many new parabolic trough solar thermal power plants are being created and they are being maintained under some better development.
The rising demand for C02 and green power lessens the power technologies has supported raising the demand for the technologies to the world. Many new parabolic trough plants are recently being constructed or are being operated in an early stage along with the support of solar portfolio standards in Nevada and Arizona and along with a solar tariff premium in the Spain region.
2. Central Receiver Power Plant
The Central Receiver Power Plant is widely known for its enormous scale plants that have usually been built to generate a steam cycle. The center position of the receiver provides universal benefits that gather all the energy within one location and it effectively secures the network of transport. At the same time, the fixed position of the center of the receiver might experience some outcomes in the limitations of the light collection; the heliostats are consistently being oriented with an angle into the straight beam, the amount of energy being gathered is being less compared to the parabolic parameter.
Hence, to enhance the efficiencies of the light concentration, the sizes of the gathered field is been improved which have been brought into some consideration which involves, excessive environmental impacts, land use, and excessive price of capital. The outstanding potential for the advancing enormous scale central receiver solar plants that have been allocated to the deserts and within the wide arid area that contains better sunshine and along with small land value with better industries and applications.
The central receiver power plant contains the highest temperature which can be used in the gas turbines and integrated cycles. During and along with the 15 years of experiments, the central receiver solar thermal power plants have been verified they become technologically constructive, and unique types of heat transfer media are being used which involve molten salts, steam air, and particles can be used, along with unique thermodynamic cycles.
3. Solar Chimney Power Plant
The Solar Chimney power plant is a type of solar thermal power plant. It was established by Professor J. Schlaic during the 1970s and the 1980s they have been tested with the help of a prototype model in Manzanares, Spain. This system has some unique advantages which include, they are appropriate for the raw materials, having better operational feasibility, and they contain fewer running elements.
It contains some better overhaul and maintenance, they have cheap maintenance expenses, they have no environmental pollution, they have steady strong running, they can be easily designed and they have a better operational lifespan. It can power the requirements of developing territories and countries, particularly, in the desert region along with the substantial prospects of applications; electricity is scarce.
The solar chimneys are tall in structure and have been designed to experience the sun within the matte surface that captivates the solar radiation. In the term Solar Chimney, the sun generates the air to warm up and rise. The procedure of invading the cool air and originating hot air prepares for the ventilation between chimneys and supports to cool the building.
Solar chimneys are used to heat the building during cold weather. To make sure that the building receives the hot air, the ventilation outlet has been kept closed and vents of the interior are being opened. For those who are looking for a better power plant, solar chimney power plants are a great example that has eco-friendly options that are cost-effective and easily cool and heat the building.
4. Dish Sterling System
The most well-established kind of heat engine that is utilized in the systems of dishes is the sterling system. The Dish/Sterling System is also known as a kind of Concentrated solar power (CSP). The sterling system operates the heated fluid that advances the pistons and generates automatic power.
The automatic power in terms of the revolution of the engine’s crankshaft operates the generator and creates electrical power. There is the enormous mirrored dish that gathers and directs the heat of the sun towards the receiver which captivates the heat and transmits it towards the fluid inside the sterling engine. The heat generates the fluid that lengthens in opposition to the piston or the turbine.
The generated mechanical power operates the generator or it remains to be the inverter that generates electricity. The Dish/Sterling System was made in June 2004 and it was created through the “Envirodish Project”. It has been constituted with the advancement step of the system of Eurodish System with many potential and improved elements.
It is also known as the best-performing system which operates well with the estimated peal of 11 kW electrical output power. The Sterling system utilizes the parabolic dish of mirrors that directs and focuses the sunlight towards the central engine which can generate electricity. This system generates smaller amounts of electricity than CSP technologies which range from up to 3 to 25 kilowatts but it is tactful for modular use. Some important parts of the system involved the power conversion unit and solar concentrator.
5. Solar Pond Power Plant
The solar Pond Power Plant is a type of solar thermal power plant and it is also known as the solar energy collector, it seems like a large pond that is larger. This Power plant is usually kept in the salty lake that captivates and saves energy from the sunlight within the warmth that remains between the ground layers of the pond.
They can be made out of nature or it has been made by man but nowadays, many ponds are artificial. The most important feature of solar panels let them function better since the solar energy collector is also known as the salt that has been concentrated along with the water.
The gradient will heavily have an impact on the water. It is alienated and will start storing from the foot of the pond along with the concentration that starts declining from the surface which provides fresh water at the top of the pond. This stored salty water is known as the “Storage Zone”. The Solar Pond has an enormous thermal mass. This pond can store heat and generate electricity from the sunlight.
Some drawbacks can outweigh the benefits, which include; the comparatively low temperature that can be achieved from this pond. The solar to electricity might be sometimes inefficacy which might include 2% of efficiency. The large pond needs to maintain its adequacy of salt concentration. Nowadays, it is extremely hard to find fresh water uniquely, in desert environments. The pond might not work effectively within the high latitude since the collection surface is horizontal and there is no other option to collect excessive sunlight.
Final thought
Solar thermal power plants are the most significant power plants that are successfully responsible for meeting the load demand. We know that the world is passing a horrible situation due to the energy crisis and the world’s natural energy reserve is depleting geometrically. For this reason, we should find renewable or other energy source.
In this case, the solar power plant can be the best choice to meet this energy crisis. It can be the best mega energy source in the future. However, we have given here some solar thermal power plant information. We have also referred to different types of solar thermal power plants that may give you a clear concept of the solar thermal power plant.
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