In 2018, the total installed capacity of Concentrated Solar Power in the world was 5,500 MW, up from 354 MW in 2005. With 2,300 MW, Spain accounted for over half of the world's Concentrated Solar Power capacity. Concentrated Solar Power, also known as concentrated solar thermal or solar thermal technology is a technique for generating electricity using mirrors. Natural sunlight is reflected, concentrated, and focused on a certain point by the mirrors, which is then transformed into heat. The heat is then utilized to create steam, which is subsequently used to power a turbine. This article will explain to you about the concentrated solar power which will be helpful in preparing the Environment syllabus for the UPSC Civil Service exam.

Concentrated Solar Power

Concentrated Solar Power (CSP) - Concept

• Concentrated Solar Power (CSP) is based on the principle of photons coming directly from the sun being concentrated without becoming scattered by the Earth's atmosphere.
• Direct normal irradiance (DNI), which is often available in subtropical locations and/or at high elevations, is the technology's principal energy source.

• Reflective surfaces that are able to follow the Sun in two or three dimensions are used to concentrate direct sunlight.
• The redirected photons heat up a fluid, which is then used to power a heat engine that generates electricity.
• As a result, CSP is also known as solar thermal electricity.
• Because CSP technology can store the heat produced, the process can be repeated indefinitely.
• It can thus be utilized on days when there is no sun, as well as before and after dawn and sunset.
• According to the International Energy Agency (IEA), CSP generation increased by an expected 34% in 2019.
• Although this exponential increase is amazing, CSP still has a long way to go before meeting its Sustainable Development Goals (SDGs), which call for average growth of 24% through 2030.

Concentrated Solar Power (CSP) - Working

• CSP systems work by concentrating the sun's solar energy onto a receiver, which then converts it to heat.
• The heat is subsequently turned into steam, which powers a turbine that generates electricity.
• Thermal energy storage devices can be used by CSP plants to store power until it is needed, such as during periods of low sunlight.
• CSP is a versatile renewable energy source because of its capacity to store energy.
• Hybrid power plants can be created by combining CSP systems with other power sources.
• CSP, for example, can be combined with thermal power stations that burn coal, natural gas, or biofuel.

Working of a Concentrated Solar Power

Concentrated Solar Power (CSP) - Technology

CSP technology is divided into four categories:

Parabolic Trough Systems

• Solar energy is concentrated via curved, trough-shaped reflectors, which are focused onto a receiver pipe in a parabolic trough system.
• The pipe normally holds thermal oil, which is heated before being utilized in a steam generator's thermal power block to generate electricity.

Power Tower Systems

• These systems track the sun and focus its energy onto a receiver at the top of a tower using heliostat mirrors.
• Inside the receiver, a fluid (typically molten salts) is heated and utilized to generate steam, which drives a turbine generator.

Linear Fresnel Systems

• There are a lot of collectors lined up in a row.
• The mirrors are positioned flat on the ground and reflect sunlight onto the receiver pipe above them.
• Fresnel can include storage in a power block or generate steam directly, similar to trough and tower systems.

Parabolic Dish Systems

• A parabolic-shaped dish serves as a concentrator, reflecting solar energy onto a receiver installed on a structure with a sun-tracking system.
• A heat engine then generates the accumulated heat.
• The dish can reach extremely high temperatures, making the technology suitable for use in solar reactors.

Concentrated Solar Power Technologies

Concentrated Solar Power (CSP) - Efficiency

• The effectiveness of a CSP system is determined by a number of factors.
• The type of system, the engine, and the receiver all contribute to the efficiency of a concentrated solar power system.
• Most CSP systems, however, have an efficiency of between 7% and 25%, according to a statistic quoted by EnergySage.
• To put things in perspective, hydropower systems can achieve efficiencies of up to 90%.
• The efficiencies of solar PV panels are comparable to that of concentrated solar power systems, with most photovoltaic panels achieving between 14 and 23 percent efficiency.

Concentrated Solar Power (CSP) - Global Installations

• Global CSP installations increased by 24% from 765MW in 2009 to 5.4GW in 2018, according to NS Energy, an online journal.
• Spain is home to the majority of the world's CSP plants, accounting for approximately 42% of all CSP installations.
• The PS10 (Planta Solar 10) in Spain was the world's first commercial utility-scale solar power tower.
• The Ouarzazate Solar Power Station, which has a capacity of 510MW, is currently the world's largest CSP plant.
• The United States is also recognized for its CSP projects, with 52 in operation, the largest of which is the 392MW Ivanpah facility in California.
• However, no new CSP projects have been announced in the United States since 2016.

Concentrated Solar Power (CSP) - India

• Only 52.5 MW of Concentrated Solar Thermal Power (CSP) capacity is operational in India.
• However, under the first phase of the Jawaharlal Nehru National Solar Mission, seven projects with a total capacity of 470 MW are expected to be completed.
• In terms of implementing Concentrating Solar Power (CSP) technology, India has the land area and adequate direct normal irradiation levels to make CSP a significant contributor to the country's energy mix.
• In April 2011, the first 2.5 MW CSP plant in India was turned on in Bikaner, Rajasthan. ACME Group built the plant, which uses eSolar power tower technology and can be scaled up to 10 MW.

Concentrated Solar Power (CSP) - Advantages

• Renewable Source: The fact that CSP is renewable is probably the most obvious advantage.
  • It has the potential to enhance air quality while also slowing the rate of climate change.
  • Unlike fossil fuels, which generate carbon dioxide when burned, CSP makes use of the earth's natural resources, making it more environmentally friendly.
• Long-term Energy Source: Its supply will never run out and may be used indefinitely, making it a long-term energy source. It also cuts down on carbon emissions.
• Predictable Source of Electricity: In comparison to solar photovoltaics (PV) and wind power, which provide intermittent supply, CSP provides a relatively constant source of electricity.
  • The power generated by CSP facilities is predictable and stable because solar energy is stored in the form of molten salts.
• Easy Conversion: Existing steam-based power facilities can readily be converted to CSP.
• Employment on Fossil Fuel Vehicles: CSP systems can also be employed in vehicles that run on fossil fuels.
• Lower Operating Cost: Because operations and maintenance are simpler, CSP plants have lower operating costs than nuclear and hydrocarbon-based plants.
• Secure Energy Grid: Concentrated solar power can be used with other energy sources to create a more secure energy grid.
• Fulfills Future Energy Demand: CSP can assist satisfy future electricity demand if it is included in the energy mix.
• Oil Recovery: It can also help with oil recovery by concentrating heavy oil so it's easier to pump with the steam it produces.
• Portable Source of Energy: It also has the potential to be used as a portable energy source.

Concentrated Solar Power (CSP) - Disadvantages

• Location Dependent: Despite its many advantages, CSP has drawbacks. Concentrated Solar Power setup depends largely on the location.
  • CSP plants, like solar PV and wind power, require a considerable amount of land to operate, making them uneconomical in densely populated areas.
• Extensive Use of Water: Water is used extensively in concentrated solar power to operate steam turbines and cool thermochemical reactors.
  • Although seawater may appear to be a viable option, it may cause problems with solar radiation in the surrounding area.
• Can Kill Species: Similarly, the light from CSP plants attracts animals, and the heat can be lethal to some species.
• High Maintenance Cost: CSP plants are very costly to operate. Materials for thermal energy storage that can resist high temperatures are expensive and difficult to come by.
  • Because molten salt solidifies at low temperatures and decomposes at high temperatures, it has a limited operational range.

Concentrated Solar Power (CSP) - Environmental Impact

Usage of More Freshwater

• The thermal cycle requires wet cooling towers, and water is also necessary to clean the mirrors and maintain their reflectivity.
• The potential of using enormous volumes of fresh water in these places is frequently criticized, especially given the growing demand for water in the Middle East and North Africa.

Visual Impact

• Another effect of CSP plants on the environment is their visual impact.
• CSP projects, unlike other energy sources such as wind power plants, are widely criticized for obstructing views of natural landscapes.

Effects on Wildlife

• The infrastructure required to operate a CSP plant, for example, can have an impact on animal populations.
• Despite the lack of cultivation in these areas, they have environmental value and provide habitat for endangered animals.
• Because of the arid character of these areas, it takes longer for the environment and community to recover from disturbances.

Toxic Emissions

• CSP plants consume more materials than fossil-fueled plants, many of which are not recyclable.
• Concentrated solar power plants also emit poisonous compounds such as biphenyl, which, when burned at high temperatures, produce dioxins, which can persist in the environment for years and provide a health risk to humans.

Greenhouse Gasses

• Because the nitrous salts used in energy storage emit nitrous oxide (N20), which affects the ozone layer, CSP plants are linked to greenhouse gas emissions.

Flora And Fauna

• Concentrated solar plants can potentially be harmful to the environment's flora and animals.
• For example, traffic routes and construction projects can disrupt the ecology and cause native wildlife to perish.

Conclusion

While the worldwide solar business has grown rapidly in recent years, the advent of concentrated solar power has had a significant influence. Globally, there are around 130 CSP projects with a total installed capacity of 5,500 MW, according to Solar Spaces. While CSP tariffs are cheaper than they have ever been, concentrated solar power still faces a number of obstacles. CSP plants are costly to build, have significant operating expenses, and there is a scarcity of funding for new projects. However, as the CSP supply chain develops and investors see the potential of CSP, research will help drive down costs, and the future of concentrated solar power will begin to look brighter.