The Ultimate Guide to Concentrated Solar Power & How CSP Solar Works
Green energy enthusiasts and industry professionals continually research the capabilities of renewable energy sources and work on implementing green energy systems. The growing energy demand requires new solutions, and that’s where new technologies emerge.
Concentrated solar-thermal power, or CSP solar, uses a mirror configuration to capture the sun’s heat and use it to generate electricity even after sunset. This technology differs a lot from traditional solar panels. CSP solar directs sunlight onto a central receiver, producing heat that can create steam to power up a turbine that produces electrical power or be part of other industrial processes.
One of the primary benefits of CSP solar is its ability to store energy. CSP plants may create power long after sunset by storing heat in materials like molten salt for hours, making them an efficient alternative to fossil fuels.
This article will examine how CSP solar works, what types of energy facilities are used, which industries can benefit, and its role in defining the future of renewable energy. If you’re interested in renewable energy, new technologies, and their capabilities, keep reading to find useful information and insights.
What Is Concentrated Solar Power?
As previously stated, CSP solar technology uses mirrors to direct sunlight to a central receiver, resulting in extreme heat. This heat is converted into electricity by a steam turbine or engine, similar to traditional coal or gas power plants, making them more easily integrated into the energy infrastructure.
CSP solar is generally used for large-scale power generation and performs particularly well in sunny locations with high direct solar exposure. Depending on the technique used, solar thermal power can generate heat at temperatures ranging from less than 400°C to more than 1000°C.
This feature makes CSP solar suitable for various industrial applications, including low-temperature food processing and high-temperature chemical processes. It can generate heat for industrial applications such as increased oil recovery, mineral processing, cement manufacturing, and iron and steel production.
How Does CSP Work?
The general approach is clear now; let’s proceed with a step-by-step process of CSP technology to understand what is happening from the moment the sun reaches the system to the moment it produces energy:
Step 1. Sunlight Collection
Large, reflective mirrors (heliostats) follow the sun and direct sunlight to a receiver at a central location. The mirrors can be arranged differently, depending on the type of the system, which we will discuss later.
Step 2. Heat Absorption
The role of the heat transfer fluid (HTF) is to transport heat from concentrated solar power to its intended destination. After being heated by the sun in the solar collector, the HTF flows to a heat exchanger to transfer its heat to water or another liquid.
Source: Inverse
Step 3. Energy Conversion
The heated fluid produces steam by boiling water in a heat exchanger. Then the high-pressure steam drives a turbine connected to an electric generator.
Step 4. Energy Storage for 24/7 Power
Excess heat can be stored in thermal energy storage systems, such as molten salt tanks, and used when sunshine is unavailable. This enables continuous power generation even during cloudy days or at night.
Step 5. Electricity Distribution
The generated electricity is fed to the grid, which supplies clean energy to the users.
CSP Solar vs. Photovoltaic (PV) Solar Systems: Key Differences
When discussing solar power, you first think about a solar panel system mounted on the house. Indeed, these are the most common solar solutions for households and businesses.
So, let’s review the main differences between CSP solar and photovoltaic (PV) solar systems and understand which client will benefit more from each technology.
| Feature | CSP Solar (Concentrated Solar-Thermal Power) | PV (Photovoltaic) Solar System |
| How It Works | Uses mirrors to focus sunlight, creating heat that powers a steam turbine | Converts sunlight directly into electricity using solar panels |
| Energy Storage | Can store thermal energy (e.g., in molten salt) for power generation after sunset. | Requires batteries for storage, which can be costly. |
| Best Use Case | Large-scale power plants for utility grids. | Residential, commercial, and large-scale installations. |
| Efficiency in Cloudy Weather | Less effective, as the system requires direct sunlight. | Works with diffused sunlight. |
| Infrastructure | Requires more space and complex setup | Easier to install and scale. |
Types of CSP Solar Technologies
There are four types of CSP solar technologies. Parabolic trough CSP is the first type of system used, while central tower CSP is the fastest growing due to better temperature capabilities. Fresnel and Dish systems are alternative types of concentrated solar power systems.
Parabolic Trough Systems
Parabolic trough CSP solar systems use mirror arrays shaped like curved troughs to direct sunlight onto specially designed pipes about a meter above the mirrors. The pipelines contain thermal oil that heats from 293ºC to 393ºC as it flows. This heated fluid then drives a traditional steam-powered energy generation mechanism.
The system is made up of numerous parallel rows of trough-shaped mirrors. Each row can rotate on a single axis to follow the sun’s daily east-west movement, ensuring sunlight is constantly focused on the receiver pipes. This technology dominates the CSP market, representing 90% of commercially operational concentrated solar power installations as of 2018.
Source: U.S. Department of Energy
Solar Power Towers
Solar power towers have a unique construction in which thousands of separate mirrors, known as heliostats, are arranged around a central tower. A heat transfer fluid receiver is located at the top of the tower. Each mirror has its tracking mechanism, continuously directing direct sunlight toward the tower’s receiver. The heated fluid is then used to drive a turbine, which generates power.
Power towers are unique among concentrated solar power plants in terms of cost-effectiveness, efficiency, and energy storage capacity. A notable example of this technology is the 10-megawatt Solar Two in Barstow, California.
Linear Fresnel Reflectors
A Linear Fresnel Reflector (LFP) is a linear concentrator technology that consists of an array of linear mirror strips that function as a Fresnel lens, focusing light onto a fixed receiver placed on a linear tower. You can imagine the LFR field as a broken-up parabolic trough reflector, though not parabolic in shape.
Dish/Engine Systems
Source: ResearchGate
Dish/engine solar systems use a parabolic mirror dish and an engine to generate electricity. The dish directs sunlight onto a central receiver, transferring heat to an engine/generator unit. Unlike other concentrated solar power technologies, these systems produce less electricity (3-25 kilowatts), yet they are useful for modular applications.
The system’s dish follows the sun throughout the day to maximize solar collection. The thermal receiver, which usually contains hydrogen or helium, absorbs the concentrated sunlight and passes the heat to a Stirling engine. This engine turns heat into mechanical energy by rotating pistons, which power a generator to produce electricity.
Future of CSP Solar Technology
The U.S. Department of Energy Solar Energy Technologies Office (SETO) supports CSP studies and development initiatives to improve performance, lower costs, and increase the life span of CSP technologies.
CSP solar costs have decreased by over 50% in the last decade due to greater efficiency and thermal energy storage, allowing for 24-hour solar power. SETO wants to reduce prices further, targeting $0.05 per kWh for baseload facilities with 12+ hours of storage.
Get your free solar quote today and see how solar thermal power can benefit you.
Source: U.S. Department of Energy
Summary & Insights
Concentrated solar-thermal power (CSP solar) is changing the energy landscape by offering industries a low-cost, dependable, and scalable renewable energy alternative. With CSP solar costs dropping by more than 50% in the last decade and developments in thermal energy storage, businesses may now benefit from 24/7 solar power, reducing reliance on fossil fuels and lowering operational expenses.
Now is the time to invest in CSP systems. Use sustainable, cost-effective energy to secure the future of your operations.
Don’t waste another second—get your free solar quote now and learn how CSP solar can help you concentrate and harness solar thermal energy.
