Exploring the Advancements and Potential of Concentrated Solar Power Technology

Posted on Jan 12, 2024 at 03:01 PM

Recently, we noted that concentrated solar power technologies have drawn the attention of governments and companies because they are a promising industry and a renewable alternative to fossil fuels, oil, gas, and coal. This happened in light of appeals from all over the world calling for the need to rely on renewable energy sources and get rid of carbon.

But the question is: What is concentrated solar power technology, and how is it done? Is it helpful or not, and what are its challenges?

Well, that's what we'll cover in today's article.

What is Concentrated Solar Power Technology?

Concentrated Solar Power (CSP) is a modern and advanced technology that reflects sunlight on many mirrors or lenses to concentrate the sunlight energy onto a receiver filled with heat transfer liquid or salts and convert it into Thermal energy. Thermal energy can then form steam to drive turbines to produce electrical power or be used in heating, water desalination, chemical production, mineral processing, and other industrial applications.

The principle of this technology is to concentrate the solar radiation that extends over large areas on a spot or a small area. This method allows storing heat to generate electricity during sunset, before sunrise, or cloudy periods. This feature makes concentrated solar energy a flexible source of thermal energy.

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Concentrated Solar Power can also be integrated into other power plants, such as geothermal, natural gas, or fossil fuel plants. To ensure continuity of production during periods of low solar radiation.

In recent years, concentrated solar power plants have been installed mainly in African and Asian countries. After that, it was a monopoly in North America and Europe. More concentrated solar power projects will likely be developed as design and operating costs continue to drop and more regulatory frameworks are in place.

Spain is the global leader in this technology. The country has the most concentrated solar power installations globally, with 50 power plants adding up to 2,300 MW. In 2021, concentrated solar power generation reached 4,719 MWh, accounting for 1.84 per cent of the total electricity demand that year.

What Are The Most Common Types of Concentrated Solar Power Systems?

There are four main types of concentrated solar power technology. The parabolic trough system is the oldest, and the central tower is the fastest-growing since 2017. Moreover, there is a Fresnel system and a Parabolic dish–Stirling system. Below are these types in detail:

• Parabolic Trough Systems:

This type uses single-axis reflectors placed within a trough in parallel rows and curved in a parabolic shape. This allows the sun to be tracked continuously from morning to evening, ensuring its continued reflection on a tube extending over the surface of the curved reflectors at a height of about one meter.

Over time, the temperature of the heat-transferring fluid within the tube, usually oil, rises from 293 °C to 393 °C, which is then used to operate a conventional steam generator.

• Central Tower CSP Systems:

In this type, a tower with a receiver at the top and surrounded by reflective mirrors known as heliostats is used. These biaxial reflectors collect the radiation and focus it on the top of the tower to heat the liquid to about 600 degrees Celsius to generate steam.

• Linear Fresnel Systems:

It is a system similar to the parabolic trough system. Here, the reflective mirrors are placed in linear rows but flat on the ground to reflect more radiation than the parabolic reflectors up again where the liquid-filled tube is.

• Parabolic dish–Stirling system:

A Parabolic dish system consists of a parabolic shape that contains a large group of reflectors, whether mirrors or lenses, that focus the rays on a receiver condenser located at the reflector's focal point. The condenser is mounted on the structure with a two-axis tracking system to follow the radiation.

The collected heat is typically utilised directly in heat engines such as a Stirling engine mounted on the receiver moving with the dish structure.

What Are The Advantages of Concentrated Solar Power Technologies? 

Concentrated solar power technologies have some advantages and benefits, including:

• High Energy Efficiency

Solar energy economics is based on determining the efficiency of concentrated solar power installations and stations, which depends on several factors, including:

• The reflective mirror's capacity to concentrate solar radiation

• The temperature that the transfer fluid reaches and the capture area.

Based on studies, the current systems provide an efficiency ranging from 20% to 40%.

• Capacity to Store Energy Produced

With energy efficiency, storage of the energy produced is a vital factor for integrating this technology with other clean energy technologies such as wind power and photovoltaic power. concentrated solar power plants can store thermal energy for 10 to 15 hours.

What Are The Disadvantages of Concentrated Solar Power Technologies?

Concentrated solar power technologies are not without flaws, so some of them are:

• Need for High Levels of Irradiance:

The long periods of radiation required by these techniques are a significant inconvenience that limits their use in some areas that do not meet these requirements. These stations cannot be deployed in areas with less than 2000 kWh/m² per year radiation level. Typical solar radiations are available in Southern Europe and North Africa.

• High Cost of Electricity Produced:

This factor is the biggest challenge impeding the development of concentrated solar power plants. However, due to the recent developments and the expansion of these stations, it is expected that the costs of producing electricity by full solar power will decrease to low values compared to before.

What Is the Future of Concentrated Solar Power Technologies?

Global research is heading toward increasing the efficiency of concentrated solar power plants. As is well known, thanks to the law of thermodynamics, thermal energy conversion efficiencies rise with increasing temperature. Therefore, today's trend is about raising temperatures to 700 or 800ºC in the reception towers.

Given that it is impractical to use steam at high temperatures, the current goal is to find an alternative to steam and to use molten salt instead. A combination of sodium and potassium nitrate in concentration towers is heated until 600 to 800 °C. These molten salts are then stored in thermally insulated deposits in the ground. So, those salts are used later to obtain electricity.

In Conclusion,

In the coming years, we will see more concentrated solar power plants in sunny countries. However, costs must decline significantly in the next phase to make a difference and become more competitive to keep pace with photovoltaic energy (PV).