There are many types of solar thermal systems, but one of the most common and efficient is the parabolic trough system.
An ingenious technology, the parabolic trough system is fast becoming the preferred choice for many commercial and industrial solar thermal applications.
What is a Parabolic Trough System?
Used mainly in commercial applications, this system uses a long, curved mirror to reflect and focus sunlight onto a receiver pipe that runs the length of the mirror.
The heat from the sun is transferred to a fluid running through the receiver pipe, which is then used to generate electricity or power industrial processes.
The system is designed to be a concentrated solar power (CSP) system, which means it uses mirrors to concentrate sunlight onto a small area to create high temperatures.
Related: How Do Solar Panels Work?
How Does It Work?
The parabolic trough system is made up of a few key components:
• Mirrors: The curved mirrors are positioned so that they reflect and focus sunlight onto the receiver pipe.
They are usually made of glass or metal and can be either fixed or tracking (able to move to follow the sun).
• Receiver pipe: This runs the length of the mirror and contains a fluid that transfers heat from the sun to a heat exchanger.
It is usually made of metal and has an absorber coating to help transfer heat more efficiently.
• Heat exchanger: This is where the heat from the fluid in the receiver pipe is transferred to water or another fluid, which is then used to generate electricity or power industrial processes.
• Fluid: The fluid inside the receiver pipe can be either water or oil.
Water is a more common choice because it has a higher heat capacity than oil, meaning it can store more heat.
This means that the system can continue generating electricity or power even when the sun isn’t shining directly on the mirrors.
Advantages of Parabolic Trough Systems
There are many advantages to using parabolic trough systems, including:
• High efficiency: Parabolic trough systems are very efficient at converting sunlight into heat, with conversion rates of up to 95%.
• Flexibility: The systems can be used to generate electricity or power industrial processes.
• Scalability: Parabolic trough systems can be scaled up or down to meet the needs of any application.
Disadvantages of Parabolic Trough Systems
There are also some disadvantages to using parabolic trough systems, including:
• High initial cost: The initial cost of a parabolic trough system can be quite high, making them less suitable for small-scale applications.
• Maintenance: Parabolic trough systems require regular maintenance and cleaning to ensure they continue to operate at peak efficiency.
• Weather Dependent: The system’s performance can be affected by weather conditions, such as clouds of dust.
How much energy does parabolic trough produce?
The process is cost-effective and, for heating the tube, thermal efficiency ranges from 60 to 80 percent.
The overall efficiency including collector to the grid, i.e. (Electrical Output Power)/(Total Impinging Solar Power), is around 15%, comparable to PV (Photovoltaic Cells) but lower than Stirling dish concentrators.