Solar thermal power technology uses various methods to focus light energy to a target in order to generate heat that is converted into electrical energy. Initially, the focused solar heat energy was used to heat water into steam, which would then turn a turbine. However, while the current designs use the same basic concept, other liquids are used in place of water, one such example is molted salt. The use of these salts has the added benefit of better energy storage, which means that the systems can be used to heat water and turn turbines long after the sun has gone down.
The solar thermal power technology relies on parabolic troughs, solar power towers, and solar dishes to create solar thermal energy that is used to create electric power. This solar power technology differs from solar photo-voltaic power in that the sun’s heat, as opposed to the sun’s light, is used to generate electricity.
The world’s first solar thermal power station was built in Egypt by Frank Shuman, a US inventor, using parabolic troughs technology between 1912 and 1913. The system powered an engine that could pump more than 22 thousand litres of water per minute. The discovery of cheap oil slowed the development of solar energy power, until the interest in the technology was revived again in the 70s. At the moment, with the environment in real threat of permanent degradation due to the use of non-renewable energy, solar power is more important than ever, with bigger projects coming up every year to harness the extensive power of the sun.
Pros and Cons of Solar Thermal Power Technology
There are several pros to using solar thermal power technology.
1. The most glaring benefit is that this source of electricity is renewable, which is good for the environment.
2. This form of solar power is also highly efficient, with ongoing developments projected to improve this aspect much further.
3. The Solar thermal power tower also offers a good value for money proposition. Again, ongoing developments in the field are projected to substantially lower the cost of this form of power and make it more viable for the average person in the near future.
The cons of using this kind of solar power include the following.
1. Limited sunlight in some locations inhibits the use of solar thermal power in many places. This is why many of its power generation plants are located in tropical areas with high levels of sunlight.
2. The initial cost of setting up a solar thermal power station is quite high, which clearly hinders its development.
3. Recently, evidence has come to light that some of the newly installed projects where causing bird deaths. It seems that the industry has recently solved this issue by using a different method of moving and parking the heliostat mirrors.
Top 5 Solar Thermal Power Companies
1. Abengoa Solar (Spain) (www.abengoa.com)
Established in 1941, Abengoa has been responsible for some of the largest solar thermal power projects in the world, for instance, Solana Generating Station in Spain.
2. BrightSource Energy (United States) (www.brightsourceenergy.com)
BrightSource is headquartered in Oakland, California. The company creates designs of utility-scale solar power projects making it one of the best ranked green energy companies in the world. BrightSource is the developer of the largest solar thermal power plant in the world, Ivanpah Solar Power Facility in the US, which was co-funded by other companies.
3. Acciona (Spain) (www.acciona.com)
Renewable energy is one of the things this multi-million dollar company dabbles in besides development and management of industrial, construction, and water infrastructure.
4. Schott AG (Germany) (www.schott.com)
Schott AG was founded in 1884 with a focus on manufacture of premium specialty glass, some of which is used in generation of solar energy. The company has also created two mega-sized solar thermal power plants in the US.
5. Torresol Energy (www.torresolenergy.com)
This company focuses on building alternative energy products and projects, including solar thermal power technology such as Gemasolar, which is the first commercial power project of its kind for using molten salt as part of its heat storage technology.
Top 7 Solar Thermal Power Tower Projects In The World
1. Ivanpah Solar Power Facility
The solar power project has a capacity of 392 MW. Ivanpah relies on solar power tower technology and is located in California, US. The construction of this project cost its co-owners whopping $2.2 billion.
2. SEGS (Solar Energy Generating Systems)
SEGS relies on parabolic trough technology and has a capacity to generate 354 MW of electricity. The solar power station is located in California, in Mojave Desert. SEGS consists of nine plants constructed between 1985 and 1991, and the exact cost of the project is not clear. However, experts estimate that the cost of the plant can be estimated based on the assumption that each of the plant’s kW cost about $3,845. Given that the plant has a capacity of 354,000 kW, the estimate total cost of the SEGS plant should be around $1.36 billion.
3. Mojave Solar Project
The Mojave Solar Project is located in Barstow in California, USA. The station generates 280 MW of power using parabolic trough technology. The project cost an estimated $1.6 billion.
The project is located in Arizona, USA, and generates 280 MW of power, just like its counterpart, Mojave Solar Project in California. This station relies on parabolic trough technology. The project cost $2 billion to construct.
5. Genesis Solar Energy Project
This project is found in Blythe, California, and is has the capacity to generate 250 MW of power using parabolic trough technology. The cost of constructing this project was $1.13 billion.
Unlike the other five solar power projects, Solaben is found in Spain. This 200-MW power project relies on parabolic trough technology. The project cost $684 million for the first phase and $273 million for the second for a combined cost of $957 million.
7. Solnova Solar Power Station (www.youtube.com/watch?v=ny214PrH4Bo)
Another Spanish solar power station, Solnova has the capacity to produce 150 MW of electricity. Solnova uses parabolic trough technology. This solar power station cost about $950 million to construct.
The Future of Solar Thermal Power Technology
Obviously, the greatest challenges solar thermal power technology needs to overcome, as is usually the case with all forms of renewable energy, is cost and efficiency. This explains why most research in the field is focused on lowering the cost of this form of solar energy from the current 5.47 cents per kWh in order to make it a viable competitor to conventional non-renewable power sources.
Regarding efficiency, solar thermal power faces challenges with regard to power storage. Unlike, say, hydroelectric power, once the sun goes down, the production of solar thermal power goes off as well. New designs are using fluids that have energy storage capacities of several hours to ensure electricity continues to be supplied long after the sun sets. Some systems can store energy for up to 9 hours after the sun goes down.