Concentrated solar power

Concentrated solar power (CSP) are systems that use lenses or mirrors to concentrate a large area of sunlight, or solar thermal energy, onto a small area. Electrical power is produced when the concentrated light is converted to heat which drives a heat engine (usually a steam turbine) connected to an electrical power generator.
CSP should not be confused with photovoltaics, where solar power is directly converted to electricity without the use of steam turbines. The concentration of sunlight onto photovoltaic surfaces, similar to CSP, is known as concentrated photovoltaics (CPV).

Concentrated sunlight has been used to perform useful tasks from the time of ancient China. A legend has it that Archimedes used a "burning glass" to concentrate sunlight on the invading Roman fleet and repel them from Syracuse. In 1973 a Greek scientist, Dr. Ioannis Sakkas, curious about whether Archimedes could really have destroyed the Roman fleet in 212 BC lined up nearly 60 Greek sailors, each holding an oblong mirror tipped to catch the Sun’s rays and direct them at a tar-covered plywood silhouette 160 feet away. The ship caught fire after a few minutes; however, historians continue to doubt the Archimedes story.
In 1866, Auguste Mouchout used a parabolic trough to produce steam for the first solar steam engine. The first patent for a Solar Collector was obtained by the Italian Alessandro Battaglia in Genoa, Italy, in 1886. Over the following years, inventors such as John Ericsson and Frank Shuman developed concentrating solar-powered devices for irrigation, refrigeration, and locomotion. In 1913 Shuman finished a 55 HP parabolic solar thermal energy station in Meadi, Egypt for irrigation.
Another Genoese, Professor Giovanni Francia (1911–1980), designed and built the first solar concentrated plant which entered in operation in Sant’Ilario, near Genoa, Italy in 1968. This plant had the architecture of today’s solar concentrated plants with a solar receiver in the center of a field of solar collectors. The plant was able to produce 1 MW with superheated steam at 100 bar and 500 degrees celsius. The 10 MW Solar One power tower was developed in Southern California in 1981 but the parabolic trough technology of the nearby Solar Energy Generating Systems (SEGS), begun in 1984, was more workable. The 354 MW SEGS is still the largest solar power plant in the world.
CSP is used to produce renewable heat or cool or electricity (called solar thermoelectricity, usually generated through steam). CST systems use lenses or mirrors and tracking systems to focus a large area of sunlight onto a small area. The concentrated light is then used as heat or as a heat source for a conventional power plant (solar thermoelectricity).
Concentrating technologies exist in four common forms, namely parabolic trough, dish stirlings, concentrating linear fresnel reflector, and solar power tower. Each concentration method is capable of producing high temperatures and correspondingly high thermodynamic efficiencies, but they vary in the way that they track the Sun and focus light. Due to new innovations in the technology, concentrating solar thermal is becoming more and more cost-effective.
A design which requires water for condensation or cooling may conflict with location of solar thermal plants in desert areas with good solar radiation but limited water resources. The conflict is illustrated by plans of Solar Millennium, a German company, to build a plant in the Amargosa Valley of Nevada which would require 20% of the water available in the area. Some other projected plants by the same and other companies in the Mojave Desert of California may also be affected by difficulty in obtaining adequate and appropriate water rights. California water law currently prohibits use of potable water for cooling.

Other designs require less water. The proposed Ivanpah Solar Power Facility in south-eastern California will conserve scarce desert water by using air-cooling to convert the steam back into water. Compared to conventional wet-cooling, this results in a 90 percent reduction in water usage . The water is then returned to the boiler in a closed process which is environmentally friendly.
Parabolic Trough

A parabolic trough is a type of solar thermal energy collector. It is constructed as a long parabolic mirror (usually coated silver or polished aluminum) with a Dewar tube running its length at the focal point. Sunlight is reflected by the mirror and concentrated on the Dewar tube. The trough is usually aligned on a north-south axis, and rotated to track the sun as it moves across the sky each day.
Alternatively the trough can be aligned on an east-west axis, this reduces the overall efficiency of the collector, due to cosine loss, but only requires the trough to be aligned with the change in seasons, avoiding the need for tracking motors. This tracking method works correctly at the spring and fall equinoxes with errors in the focusing of the light at other times during the year (the magnitude of this error varies throughout the day, taking a minimum value at solar noon). There is also an error introduced due to the daily motion of the sun across the sky, this error also reaches a minimum at solar noon. Due to these sources of error, seasonally adjusted parabolic troughs are generally designed with a lower solar concentration ratio. In order to increase the level of alignment, some measuring devices have also been invented.
Heat transfer fluid (usually oil) runs through the tube to absorb the concentrated sunlight. This increases the temperature of the fluid to some 400°C. The heat transfer fluid is then used to heat steam in a standard turbine generator. The process is economical and, for heating the pipe, thermal efficiency ranges from 60-80%. The overall efficiency from collector to grid, i.e. (Electrical Output Power)/(Total Impinging Solar Power) is about 15%, similar to PV (Photovoltaic Cells) but less than Stirling dish concentrators.
Current commercial plants utilizing parabolic troughs are hybrids; fossil fuels are used during night hours, but the amount of fossil fuel used is limited to a maximum 27% of electricity production, allowing the plant to qualify as a renewable energy source. Because they are hybrids and include cooling stations, condensers, accumulators and other things besides the actual solar collectors, the power generated per square meter of area varies enormously.

Power Tower

The solar power tower (also known as ‘Central Tower’ power plants or ‘Heliostat’ power plants or power towers) is a type of solar furnace using a tower to receive the focused sunlight. It uses an array of flat, movable mirrors (called heliostats) to focus the sun’s rays upon a collector tower (the target).
Early designs used these focused rays to heat water, and used the resulting steam to power a turbine. However, designs using liquid sodium in place of water have been demonstrated; this is a metal with high heat capacity, which can be used to store the energy before using it to boil water to drive turbines. These designs allow power to be generated when the sun is not shining.
The 10 MW Solar One and Solar Two heliostat demonstration projects in the Mojave Desert have now been decommissioned. The 15 MW Solar Tres Power Tower in Spain builds on these projects. In Spain, the 11 MW PS10 solar power tower and 20 MW PS20 solar power tower have been recently completed. In South Africa, a 100 MW solar power plant is planned with 4000 to 5000 heliostat mirrors, each having an area of 140 m². A site near Upington has been selected.
eSolar unveiled Sierra SunTower in the summer of 2009, a 5 MW plant located in Lancaster, California about 80 km (50 miles) northeast of Los Angeles. The project site occupies approximately 8 hectares (20 acres) in an arid valley in the western corner of the Mojave Desert at 35° north latitude. Sierra SunTower is interconnected to the Southern California Edison (SCE) grid and is the only CSP tower facility operating in North America.
BrightSource Energy entered into a series of power purchase agreements with Pacific Gas and Electric Company in March 2008 for up to 900 MW of electricity, the largest solar power commitment ever made by a utility. BrightSource is currently developing a number of solar power plants in Southern California, with construction of the first plant planned to start in 2009.
In June 2008, BrightSource Energy dedicated its Solar Energy Development Center (SEDC) in Israel’s Negev Desert. The site, located in the Rotem Industrial Park, features more than 1,600 heliostats that track the sun and reflect light onto a 60 meter-high tower. The concentrated energy is then used to heat a boiler atop the tower to 550 degrees Celsius, generating steam that is piped into a turbine, where electricity can be produced.
The US National Renewable Energy Laboratory (NREL) has estimated that by 2020 electricity could be produced from power towers for 5.47 cents per kWh. hopes to develop cheap, low maintenance, mass producible heliostat components to reduce this cost in the near future.
* Some Concentrating Solar Power Towers are air-cooled instead of water-cooled, to avoid using limited desert water
* Flat glass is used instead of the more expensive curved glass
* Some store the heat in molten salt containers to continue producing electricity while the sun is not shining
* Steam is heated to 500 C to drive turbines which generate electricity
Generally, installations uses from 150 hectares (1,500,000 m2) to 320 hectares (3,200,000 m2).
Recently, there has been a renewed interest in solar tower power technology, as is evident from the fact that there are several companies involved in planning, designing and building utility size power plants. This is an important step towards the ultimate goal of developing commercially viable plants. There are numerous example of case studies of applying innovative solution to solar power.
The Pit Power Tower combines a Solar Power Tower and an Aero-electric Power Tower in a decommissioned open pit mine. Traditional Solar Power Towers are constrained in size by the height of the tower and closer heliostats blocking the line of sight of outer heliostats to the receiver. The use of the pit mine’s "stadium seating" helps overcome the blocking constraint.
As Solar Power Towers commonly use steam to drive the turbines, and water tends to be scarce in regions with high solar energy, another advantage of open pits is that they tend to collect water, having been dug below the water table. The Pit Power Tower uses low heat steam to drive the Pneumatic Tubes in a co-generation system. A third benefit of re-purposing a pit mine for this kind of project is the possibility of reusing mine infrastructure such as roads, buildings and electricity.
Parabolic Dish
A dish stirling or dish engine system consists of a stand-alone parabolic reflector that concentrates light onto a receiver positioned at the reflector’s focal point. The reflector tracks the Sun along two axes. The working fluid in the receiver is heated to 250–700 °C and then used by a Stirling engine to generate power.
Parabolic dish systems provide the highest solar-to-electric efficiency among CSP technologies, and their modular nature provides scalability. The Stirling Energy Systems (SES) and Science Applications International Corporation (SAIC) dishes at UNLV, and Australian National University’s Big Dish in Canberra, Australia are representative of this technology.
A dish system uses a large, reflective, parabolic dish (similar in shape to satellite television dish). It focuses all the sunlight that strikes the dish up onto to a single point above the dish, where a receiver captures the heat and transforms it into a useful form. Typically the dish is coupled with a Stirling engine in a Dish-Stirling System, but also sometimes a steam engine is used. These create rotational kinetic energy that can be converted to electricity using an electric generator.
The advantage of a dish system is that it can achieve much higher temperatures due to the higher concentration of light (as in tower designs). Higher temperatures leads to better conversion to electricity and the dish system is very efficient on this point. However, there are also some disadvantages. Heat to electricity conversion requires moving parts and that results in maintenance. In general, a centralized approach for this conversion is better than the dencentralized concept in the dish design. Second, the (heavy) engine is part of the moving structure, which requires a rigid frame and strong tracking system. Furthermore, parabolic mirrors are used instead of flat mirrors and tracking must be dual-axis.
In 2005 Southern California Edison announced an agreement to purchase solar powered Stirling engines from Stirling Energy Systems over a twenty year period and in quantities (20,000 units) sufficient to generate 500 megawatts of electricity. Stirling Energy Systems announced another agreement with San Diego Gas & Electric to provide between 300 and 900 megawatts of electricity. In January 2010, Stirling Energy Systems and Tessera Solar commissioned the first demonstration 1.5-megawatt power plant ("Maricopa Solar") using Stirling technology in Peoria, Arizona.

Fresnel solar reflectors

A Concentrating Linear Fresnel Reflector (CLFR) – also referred to as a Compact Linear Fresnel Reflector – is a specific type of Linear Fresnel Reflector (LFR) technology. Linear Fresnel Reflectors use long, thin segments of mirrors to focus sunlight onto a fixed absorber located at a common focal point of the reflectors. These mirrors are capable of concentrating the sun’s energy to approximately 30 times its normal intensity. This concentrated energy is transferred through the absorber into some thermal fluid (this is typically oil capable of maintaining liquid state at very high temperatures). The fluid then goes through a heat exchanger to power a steam generator. As opposed to traditional LFR’s, the CLFR utilizes multiple absorbers within the vicinity of the mirrors.
The first Linear Fresnel Reflector was developed in Italy in 1961 by Giorgio Francia of the University of Genoa. Francia demonstrated that such a system could create elevated temperatures capable of making a fluid do work. The technology was further investigated by companies such as the FMC Corporation during the 1973 oil crisis, but remained relatively untouched until the early 1990s. In 1993, the first CLFR was developed at the University of Sydney in 1993 and patented in 1995. In 1999, the CLFR design was enhanced by the introduction of the advanced absorber.

The reflectors are located at the base of the system and converge the sun’s rays into the absorber. A key component that makes all LFR’s more advantageous than traditional parabolic trough mirror systems is the use of Fresnel reflectors. These reflectors make use of the Fresnel lens effect, which allows for a concentrating mirror with a large aperture and short focal length while simultaneously reducing the volume of material required for the reflector. This greatly reduces the system’s cost since sagged-glass parabolic reflectors are typically very expensive. It should be noted, however, that in recent years thin-film nanotechnology has significantly reduced the cost of parabolic mirrors.

A major challenge that must be addressed in any solar concentrating technology is the changing intensity of the incident rays (the rays of sunlight striking the mirrors) as the sun progresses throughout the day. The reflectors of a CLFR are typically aligned in a north-south orientation and turn about a single axis using a computer controlled solar tracker system. This allows the system to maintain the proper angle of incidence between the sun’s rays and the mirrors, thereby optimizing energy transfer.

The absorber is located at the focal point of the mirrors. It runs parallel to and above the reflector segments to transport radiation into some working thermal fluid. The basic design of the absorber for the CLFR system is an inverted air cavity with a glass cover enclosing insulated steam tubes. This design has been demonstrated to be simple and cost effective with good optical and thermal performance.

For optimum performance of the CLFR, several design factors of the absorber must be optimized.

* First, heat transfer between the absorber and the thermal fluid must be maximized. This relies on the surface of the steam tubes being selective. A selective surface optimizes the ratio of energy absorbed to energy emitted. Acceptable surfaces generally absorb 96% of incident radiation while emitting only 7% through infra-red radiation. Electro-chemically deposited black chrome is generally used for its ample performance and ability to withstand high temperatures.
* Second, the absorber must be designed so that the temperature distribution across the selective surface is uniform. Non-uniform temperature distribution leads to accelerated degradation of the surface. Typically, a uniform temperature of 300 °C is desired. Uniform distributions are obtained by changing absorber parameters such as the thickness of insulation above the plate, the size of the aperture of the absorber and the shape and depth of the air cavity.

As opposed to the traditional LFR, the CLFR makes use of multiple absorbers within the vicinity of its mirrors. These additional absorbers allow the mirrors to alternate their inclination. This arrangement is advantageous for several reasons.

* First, alternating inclinations minimize the effect of reflectors blocking adjacent reflectors’ access to sunlight, thereby improving the systems efficiency.
* Second, multiple absorbers minimize the amount of ground space required for installation. This in turn reduces cost to procure and prepare the land.
* Finally, having the panels in close proximity reduces the length of absorber lines, which reduces both thermal losses through the absorber lines and overall cost for the system.

In March 2009, the German company Novatec Biosol constructed the Fresnel solar power plant known as PE 1. The solar thermal power plant is based on CLFR technology and has an electrical capacity of 1.4 MW. PE 1 comprises a solar boiler with mirror surface of approximately 18,000 m2. The steam is generated by concentrating sunlight directly onto a linear receiver, which is 7.40 metres above the ground. An absorber tube is positioned in the focal line of the mirror field where water is heated into 270 °C (543 K; 518 °F) saturated steam. This steam in turn powers a generator.
The commercial success of the PE 1 has led Novatec Biosol to design a 30 MW solar power plant known as PE 2. PE 2 will be constructed in Murcia, Spain in 2010. Novatec Biosol has also obtained permits for another 60 MW of related projects.
In April 2008, the solar thermal company Ausra opened a large factory in Las Vegas, Nevada that will produce linear Fresnel reflectors[7]. The factory will be capable of producing enough solar collectors to provide 200 MW of power per month.
Ausra has finished construction of the 5 MW Kimberlina Solar Thermal Energy plant in Bakersfield, California. This is the first commercial linear Fresnel reflector plant in the United States. The solar collectors were produced at the Ausra factory in Las Vegas.
Ausra also built and operates a linear fresnel reflector plant in New South Wales, Australia. This reflector plant supplements the 2,000 MW coal-fired Liddell Power Station. The power generated by the solar thermal steam system is used to provide electricity for the plant’s operation, offsetting the plant’s internal power usage.

As this renewable source of energy is inconsistent by nature, methods for energy storage have been studied, for instance the single-tank (thermocline) storage technology for large-scale solar thermal power plants. The thermocline tank approach uses a mixture of silica sand and quartzite rock to displace a significant portion of the volume in the tank. Then it is filled with the heat transfer fluid, typically a molten nitrate salt.
A variety of fluids have been tested to transport the sun’s heat, including water, air, oil, and sodium, but molten salt was selected as best. Molten salt is used in solar power tower systems because it is liquid at atmosphere pressure, it provides an efficient, low-cost medium in which to store thermal energy, its operating temperatures are compatible with today’s high-pressure and high-temperature steam turbines, and it is non-flammable and nontoxic. In addition, molten salt is used in the chemical and metals industries as a heat-transport fluid, so experience with molten-salt systems exists in non-solar settings.
The molten salt is a mixture of 60 percent sodium nitrate and 40 percent potassium nitrate, commonly called saltpeter. New studies show that calcium nitrate could be included in the salts mixture to reduce costs and with technical benefits. The salt melts at 220 °C (430 °F) and is kept liquid at 290 °C (550 °F) in an insulated storage tank. The uniqueness of this solar system is in de-coupling the collection of solar energy from producing power, electricity can be generated in periods of inclement weather or even at night using the stored thermal energy in the hot salt tank. Normally tanks are well insulated and can store energy for up to a week. As an example of their size, tanks that provide enough thermal storage to power a 100-megawatt turbine for four hours would be about 9 m (30 ft) tall and 24 m (80 ft) in diameter.
The Andasol power plant in Spain is the first commercial solar thermal power plant to utilize molten salt for heat storage and nighttime generation. It came online March 2009.
The proposed power plant in Cloncurry Australia will store heat in purified graphite. The plant has a power tower design. The graphite is located on top of the tower. Heat from the heliostats goes directly to the storage. Heat for energy production is drawn from the graphite. This simplifies the design.
Molten salt coolants are used to transfer heat from the reflectors to heat storage vaults. The heat from the salts are transferred to a secondary heat transfer fluid via a heat exchanger and then to the storage media, or alternatively, the salts can be used to directly heat graphite. Graphite is used as it has relatively low costs and compatibility with liquid fluoride salts. The high mass and volumetric heat capacity of graphite provide an efficient storage medium.
Phase Change Material (PCMs) offer an alternate solution in energy storage. Using a similar heat transfer infrastructure, PCMs have the potential of providing a more efficient means of storage. PCMs can be either organic or inorganic materials. Advantages of organic PCMs include no corrosives, low or no undercooling, and chemical and thermal stability. Disadvantages include low phase-change enthalpy, low thermal conductivity, and flammability. Inorganics are advantageous with greater phase-change enthalpy, but exhibit disadvantages with undercooling, corrosion, phase separation, and lack of thermal stability. The greater phase-change enthalpy in inorganic PCMs make hydrate salts a strong candidate in the solar energy storage field.


Other renewables
International Programs

The cost of building a CSP station was typically about $2.5 to $4 per watt, while the fuel (the sun’s radiation) is free. Therefore a 250 MW CSP station would have cost $600–1000 million to build. That works out to 12 to 18 cents per kilowatt-hour.
A study done by Greenpeace International, the European Solar Thermal Electricity Association, and the International Energy Agency’s SolarPACES group investigated the potential and future of concentrated solar power. The study found that concentrated solar power could account for up to 25% of the world’s energy needs by 2050. The increase in investment would be from 2 billion euros worldwide to 92.5 billion euros in that time period.

Spain is the leader in concentrated solar power technology, with more than 50 projects approved by the government in the works. Also, it exports its technology, further increasing the technology’s stake in energy worldwide. Because of the nature of the technology needing a desert like area, experts predicted the biggest growth in places like Africa, Mexico, the southwest United States. The study examined three different outcomes for this technology: no increases in CSP technology, investment continuing as it has been in Spain and the US, and finally the true potential of CSP without any barriers on its growth.

Finally, the study acknowledged how technology for CSP was improving and how this would result in a drastic price decrease by 2050. It predicted a drop from the current range of .23 to .15 euros per kilowatthour, down to .14 to .10 euros a kilowatthour.
Recently the EU has begun to look into developing a €400 billion ($774 billion) solar power plant based in the Sahara region using CSP technology known as Desertec. It is part of a wider plan to create "a new carbon-free network linking Europe, the Middle East and North Africa".
The plan is backed mainly by German industrialists and predicts production of 15% of Europe’s power by 2050. Morocco is a major partner in Desertec and as it has barely 1% of the electricity consumption of the EU, it will produce more than enough energy for the entire country with a large energy surplus to deliver to Europe.
Other organizations expect CSP to cost $0.06(US)/kWh by 2015 due to efficiency improvements and mass production of equipment. That would make CSP as cheap as conventional power. Investors such as venture capitalist Vinod Khosla expect CSP to continuously reduce costs and actually be cheaper than coal power after 2015.
On September 9, 2009; 14 months ago (2009-09-09), Bill Weihl,’s green energy czar said that the firm was conducting research on the heliostat mirrors and gas turbine technology, which he expects will drop the cost of solar thermal electric power to less than $0.05/kWh in 2 or 3 years.
In 2009, scientists at the National Renewable Energy Laboratory (NREL) and SkyFuel teamed to develop large curved sheets of metal that have the potential to be 30% less expensive than today’s best collectors of concentrated solar power by replacing glass-based models with a silver polymer sheet that has the same performance as the heavy glass mirrors, but at a much lower cost and much lower weight. It also is much easier to deploy and install. The glossy film uses several layers of polymers, with an inner layer of pure silver.
Levelised cost
Since a solar power plant does not use any fuel, the cost consists mostly of capital cost with minor operational and maintenance cost. If the lifetime of the plant and the interest rate is known, then the cost per kWh can be calculated. This is called the levelised energy cost.
The first step in the calculation is to determine the investment for the production of 1 kWh in a year. Example, the fact sheet of the Andasol 1 project shows a total investment of 310 million euros for a production of 179 GWh a year. Since 179 GWh is 179 million kWh, the investment per kWh a year production is 310 / 179 = 1.73 euro. Another example is Cloncurry solar power station in Australia. It is planned to produce 30 million kWh a year for an investment of 31 million Australian dollars. So, if this is achieved in reality, the cost would be 1.03 Australian dollar for the production of 1 kWh in a year. This would be significantly cheaper than Andasol 1, which can partially be explained by the higher radiation in Cloncurry over Spain. The investment per kwh cost for one year should not be confused with the cost per kwh over the complete lifetime of such a plant.
In most cases the capacity is specified for a power plant (for instance Andasol 1 has a capacity of 50MW). This number is not suitable for comparison, because the capacity factor can differ. If a solar power plant has heat storage, then it can also produce output after sunset, but that will not change the capacity factor, it simply displaces the output. The average capacity factor for a solar power plant, which is a function of tracking, shading and location, is about 20%, meaning that a 50MW capacity power plant will typically provide a yearly output of 50 MW × 24 hrs × 365 days × 20% = 87,600 MWh/year, or 87.6 GWh/yr.
Although the investment for one kWh year production is suitable for comparing the price of different solar power plants, it does not give the price per kWh yet. The way of financing has a great influence on the final price. If the technology is proven, an interest rate of 7% should be possible. However, for a new technology investors want a much higher rate to compensate for the higher risk. This has a significant negative effect on the price per kWh. Independent of the way of financing, there is always a linear relation between the investment per kWh production in a year and the price for 1 kWh (before adding operational and maintenance cost). In other words, if by enhancements of the technology the investments drop by 20%, then the price per kWh also drops by 20%.
If a way of financing is assumed where the money is borrowed and repaid every year, in such way that the debt and interest decreases, then the following formula can be used to calculate the division factor: (1 – (1 + interest / 100) ^ -lifetime) / (interest / 100). For a lifetime of 25 years and an interest rate of 7%, the division factor is 11.65. For example, the investment of Andasol 1 was 1.73 euro per kWh, divided by 11.65 results in a price of 0.15 euro per kWh. If one cent operation and maintenance cost is added, then the levelized cost is 0.16 euro per kWh. Other ways of financing, different way of debt repayment, different lifetime expectation, different interest rate, may lead to a significantly different number.
If the cost per kWh may follow the inflation, then the inflation rate can be added to the interest rate. If an investor puts his money on the bank for 7%, then he is not compensated for inflation. However, if the cost per kWh is raised with inflation, then he is compensated and he can add 2% (a normal inflation rate) to his return. The Andasol 1 plant has a guaranteed feed-in tariff of 0.21 euro for 25 years. If this number is fixed, after 25 years with 2% inflation, 0.21 euro will have a value comparable with 0.13 euro now.
Finally, there is some gap between the first investment and the first production of electricity. This increases the investment with the interest over the period that the plant is not active yet. The modular solar dish (but also solar photovoltaic and wind power) have the advantage that electricity production starts after first construction.
Given the fact that solar thermal power is reliable, can deliver peak load and does not cause pollution, a price of US$0.10 per kWh starts to become competitive. Although a price of US$0.06 has been claimed With some operational cost a simple target is 1 dollar (or lower) investment for 1 kWh production in a year.

List of solar thermal power stations
This is a list of solar thermal power stations. These include the 354 megawatt (MW) Solar Energy Generating Systems power installation in the USA, Solnova Solar Power Station (Spain, 150 MW), Andasol solar power station (Spain, 100 MW), Nevada Solar One (USA, 64 MW), PS20 solar power tower (Spain, 20 MW), and the PS10 solar power tower (Spain, 11 MW). The 370 MW Ivanpah Solar Power Facility, located in California’s Mojave Desert, is the world’s largest solar thermal power plant project currently under construction.
The solar thermal power industry is growing rapidly with 1.2 GW under construction as of April 2009 and another 13.9 GW announced globally through 2014. Spain is the epicenter of solar thermal power development with 22 projects for 1,037 MW under construction, all of which are projected to come online by the end of 2010. In the United States, 5,600 MW of solar thermal power projects have been announced.
In developing countries, three World Bank projects for integrated solar thermal/combined-cycle gas-turbine power plants in Egypt, Mexico, and Morocco have been approved.

Operational Solar Thermal Power Stations

354 Solar Energy Generating Systems USA Mojave Desert California parabolic trough
150 Solnova Spain Seville parabolic trough
100 Andasol solar power station Spain Granada parabolic trough
64 Nevada Solar One USA Boulder City, Nevada parabolic trough
50 Ibersol Ciudad Real Spain Puertollano, Ciudad Real parabolic trough
50 Alvarado I Spain Badajoz parabolic trough
50 Extresol 1 Spain Torre de Miguel Sesmero (Badajoz) parabolic trough
50 La Florida Spain Alvarado (Badajoz) parabolic trough
20 PS20 solar power tower Spain Seville solar power tower
17 Yazd integrated solar combined cycle power station Iran Yazd parabolic trough
11 PS10 solar power tower Spain Seville solar power tower
5 Kimberlina Solar Thermal Energy Plant USA Bakersfield, California fresnel reflector
5 Sierra SunTower USA Lancaster, California solar power tower
5 Archimede solar power plant Italy near Siracusa, Sicily parabolic trough
2 Liddell Power Station Solar Steam Generator Australia New South Wales fresnel reflector
1.5 Maricopa Solar USA Peoria, Arizona dish stirling
1.5 Jülich Solar Tower Germany Jülich solar power tower
1.4 Puerto Errado 1 Spain Murcia fresnel reflector
1 Saguaro Solar Power Station USA Red Rock Arizona parabolic trough
2 Keahole Solar Power USA Hawaii parabolic trough
0.25 Shiraz solar power plant Iran Shiraz CSP

Solar Thermal Power Stations under construction Capacity (MW)
Name Country Location Technology
370 Ivanpah Solar Power Facility USA San Bernardino County, California power tower
100 Extresol 2-3 Spain Torre de Miguel Sesmero (Badajoz) parabolic trough
100 Andasol 3–4 Spain Granada parabolic trough
100 Palma del Rio 1, 2 Spain Cordoba parabolic trough
100 Helioenergy 1, 2 Spain Ecija parabolic trough
100 Solaben 1, 2 Spain Logrosan parabolic trough
100 Valle Solar Power Station Spain Cadiz parabolic trough
100 Termosol 1+2 Spain Navalvillar de Pela (Badajoz) parabolic trough
100 Helios 1+2 Spain Ciudad Real parabolic trough
75 Martin Next Generation Solar Energy Center USA Florida ISCC
50 Majadas de Tiétar Spain Caceres parabolic trough
50 Lebrija-1 Spain Lebrija parabolic trough
50 Manchasol-1 Spain Ciudad Real parabolic trough
50 La Dehesa Spain La Garrovilla (Badajoz) parabolic trough
50 Axtesol 2 Spain Badajoz parabolic trough
50 Arenales PS Spain Moron de la Frontera (Seville) parabolic trough
50 Serrezuella Solar 2 Spain Talarrubias (Badajoz) parabolic trough
50 El Reboso 2 Spain El Puebla del Rio (Seville) parabolic trough
50 Moron Spain Moron de la Frontera (Sevilla) parabolic trough
50 Olivenza 1 Spain Olivenza (Badajoz) parabolic trough
50 Medellin Spain Medellin (Badajoz) parabolic trough
50 Valdetorres Spain Valdetorres (Badajoz) parabolic trough
50 Badajoz 2 Spain Talavera la Real (Badajoz) parabolic trough
50 Santa Amalia Spain Santa Amalia (Badajoz) parabolic trough
50 Torrefresneda Spain Torrefresneda (Badajoz) parabolic trough
50 La Puebla 2 Spain La Puebla del Rio (Sevilla) parabolic trough
25 Termosolar Borges Spain Borges Blanques (Lerida) parabolic trough
17 Gemasolar, former Solar Tres Power Tower Spain Fuentes de Andalucia (Seville) power tower
20 Kuraymat Plant Egypt Kuraymat ISCC
25Hassi R’mel integrated solar combined cycle power station Algeria Hassi R’mel ISCC
20 Beni Mathar Plant Morocco Ain Bni Mathar ISCC
1.4 THEMIS Solar Power Tower France Pyrénées-Orientales solar power tower
1 Renovalia Spain Albacete dish
1934.4 Overall capacity under construction

Stations Announced in the USA
MW Name State Location Technology
968 Blythe Solar Power Project California Riverside County solar trough
850 Calico Solar Energy Project California San Bernardino County stirling engine (SES Solar One)
750 Imperial Valley Solar Project (formerly SES Solar Two) California Imperial County stirling engine
553 Mojave Solar Park California San Bernardino County parabolic trough
500 Fort Irwin California San Bernardino County unnamed solar thermal technology, military
500 Amargosa Solar Power Project Nevada Amargosa Desert, Nye County parabolic trough
484 Palen Solar Power Project California Riverside County solar trough
350 Sonoran Solar Project Arizona Maricopa County parabolic trough
340 Hualapai Valley Solar Project Arizona Mohave County parabolic trough
300 Unnamed Florida fresnel reflector
290 Agua Caliente Solar Project Arizona Yuma County parabolic trough
280 Solana Generating Station Arizona West of Gila Bend, AZ parabolic trough
250 Beacon Solar Energy Project California Kern County parabolic trough
250 Harper Lake Solar California San Bernardino County solar trough
250 Genesis Solar Energy Project California Riverside County solar trough
242 Ridgecrest Solar Power Project California Kern County solar trough
200 Unnamed Kingman solar project Arizona Mohave County parabolic trough
200 Enviromission Australia Arizona solar tower
200 BrightSource PPA5 California Mojave power tower
200 BrightSource PPA6 California Mojave power tower
200 BrightSource PPA7 California Mojave power tower
150 Rice Solar Energy Project California Riverside County power tower
107 San Joaquin Solar 1&2 California Fresno County parabolic trough hybrid with biomass
100 Crescent Dunes Solar Energy Project Nevada Nye County power tower
92 Suntower New Mexico Doña Ana County solar tower
92 Alpine SunTower California Lancaster solar tower
84 eSolar 1 California Los Angeles County solar tower
66 eSolar 2 California Los Angeles County solar tower
62 City of Palmdale Hybrid Power Project California Palmdale parabolic trough steam input for hybrid gas plant
59 Unnamed California Barstow parabolic trough with heat storage
50 Victorville 2 Hybrid Power Project California Victorville parabolic trough steam input for hybrid gas plant
50 Sound Hybrid G Southwest Unannounced hybrid
5 Kalaeloa Solar One MicroCSP Power Project Hawaii Barbers Point Naval Air Station MicroCSP parabolic trough steam input for power generation with thermal storage
9659 Overall capacity announced in the USA

Solar Thermal Power Stations Announced in Spain
200 Andasol 4–7 Granada parabolic trough with heat storage
50 Manchasol 2 Ciudad Real parabolic trough with heat storage
100 Solnova 2, 4–5 Sevilla parabolic trough with heat storage
50 Termesol 50 Seville parabolic trough with heat storage
50 Arcosol 50 Cadiz parabolic trough with heat storage
50 Ibersol Badajoz Fuente de Cantos parabolic trough
50 Ibersol Valdecaballeros 1–2 Valdecaballeros parabolic trough
50 Ibersol Sevilla Aznalcollar parabolic trough
50 Ibersol Almería Tabernas parabolic trough
50 Ibersol Albacete Almansa parabolic trough
50 Ibersol Murcia Lorca parabolic trough
50 Ibersol Zamora Cubillos parabolic trough
50 Enerstar Villena Power Plant Villena parabolic trough
100 Aste 3, 4 Alcázar de San Juan parabolic trough (Ciudad Real)
50 Astexol 1 Extremadura parabolic trough
50 AZ 20 Sevilla power tower
50 Alcázar Solar Thermal Power Project Alcázar de San Juan power tower
20 Almaden Plant Albacete power tower
10 Gotasol Gotarrendura linear fresnel
0.08 Aznalcollar TH Sevilla dish sterling
1080.08 Overall capacity announced in Spain

Solar Thermal Power Stations Announced In Other Countries
MW Name Location Technology
2000 Sudan Solar Program Sudan unknown
2000 unknown Mongolian desert, China power tower
2000 unknown Morocco unknown
250 Ashalim power station Negev desert, Israel CSP
250 unknown Australia unknown
100 Shams Abu Dhabi Madinat Zayad, UAE parabolic trough
100 unknown Upington, South Africa power tower
12 Alba Nova 1 Corsica Island, France unknown
10 Cloncurry solar power station Cloncurry, Australia power tower with heat storage
10 unknown Nagpur, India unknown
6799.0 Overall capacity announced in other countries