Concentrated solar power

A solar power tower concentrating light via 10,000 mirrored heliostats spanning thirteen million sq ft (1.21 km2).

The three towers of the Ivanpah Solar Power Facility
Part of the 354 MW SEGS solar complex in northern San Bernardino County, California
Bird's eye view of Khi Solar One, South Africa

Concentrated solar power (CSP, also known as concentrating solar power, concentrated solar thermal) systems generate solar power by using mirrors or lenses to concentrate a large area of sunlight onto a receiver.[1] Electricity is generated when the concentrated light is converted to heat (solar thermal energy), which drives a heat engine (usually a steam turbine) connected to an electrical power generator[2][3][4] or powers a thermochemical reaction.[5][6][7]

CSP had a global total installed capacity of 5,500 MW in 2018, up from 354 MW in 2005. Spain accounted for almost half of the world's capacity, at 2,300 MW, despite no new capacity entering commercial operation in the country since 2013.[8] The United States follows with 1,740 MW. Interest is also notable in North Africa and the Middle East, as well as India and China. The global market was initially dominated by parabolic-trough plants, which accounted for 90% of CSP plants at one point.[9] Since about 2010, central power tower CSP has been favored in new plants due to its higher temperature operation — up to 565 °C (1,049 °F) vs. trough's maximum of 400 °C (752 °F) — which promises greater efficiency.

Among the larger CSP projects are the Ivanpah Solar Power Facility (392 MW) in the United States, which uses solar power tower technology without thermal energy storage, and the Ouarzazate Solar Power Station in Morocco,[10] which combines trough and tower technologies for a total of 510 MW with several hours of energy storage.

As a thermal energy generating power station, CSP has more in common with thermal power stations such as coal, gas, or geothermal. A CSP plant can incorporate thermal energy storage, which stores energy either in the form of sensible heat or as latent heat (for example, using molten salt), which enables these plants to continue to generate electricity whenever it is needed, day or night. This makes CSP a dispatchable form of solar. Dispatchable renewable energy is particularly valuable in places where there is already a high penetration of photovoltaics (PV), such as California[11] because demand for electric power peaks near sunset just as PV capacity ramps down (a phenomenon referred to as duck curve).[12]

CSP is often compared to photovoltaic solar (PV) since they both use solar energy. While solar PV experienced huge growth in recent years due to falling prices,[13][14] Solar CSP growth has been slow due to technical difficulties and high prices. In 2017, CSP represented less than 2% of worldwide installed capacity of solar electricity plants.[15] However, CSP can more easily store energy during the night, making it more competitive with dispatchable generators and baseload plants.[16][17][18][19]

Solar power tower

Ashalim Power Station, Israel, on its completion the tallest solar tower in the world. It concentrates light from over 50,000 heliostats.
The PS10 solar power plant in Andalusia, Spain, concentrates sunlight from a field of heliostats onto a central solar power tower.

A solar power tower consists of an array of dual-axis tracking reflectors (heliostats) that concentrate sunlight on a central receiver atop a tower; the receiver contains a heat-transfer fluid, which can consist of water-steam or molten salt. Optically a solar power tower is the same as a circular Fresnel reflector. The working fluid in the receiver is heated to 500–1000 °C (773–1,273 K or 932–1,832 °F) and then used as a heat source for a power generation or energy storage system.[41] An advantage of the solar tower is the reflectors can be adjusted instead of the whole tower. Power-tower development is less advanced than trough systems, but they offer higher efficiency and better energy storage capability. Beam down tower application is also feasible with heliostats to heat the working fluid.[46]

The Solar Two in Daggett, California and the CESA-1 in Plataforma Solar de Almeria Almeria, Spain, are the most representative demonstration plants. The Planta Solar 10 (PS10) in Sanlucar la Mayor, Spain, is the first commercial utility-scale solar power tower in the world. The 377 MW Ivanpah Solar Power Facility, located in the Mojave Desert, is the largest CSP facility in the world, and uses three power towers.[47] Ivanpah generated only 0.652 TWh (63%) of its energy from solar means, and the other 0.388 TWh (37%) was generated by burning natural gas. [48][49][50]

Fresnel reflectors

Fresnel reflectors are made of many thin, flat mirror strips to concentrate sunlight onto tubes through which working fluid is pumped. Flat mirrors allow more reflective surface in the same amount of space than a parabolic reflector, thus capturing more of the available sunlight, and they are much cheaper than parabolic reflectors. Fresnel reflectors can be used in various size CSPs.[51][52]

Fresnel reflectors are sometimes regarded as a technology with a worse output than other methods. The cost efficiency of this model is what causes some to use this instead of others with higher output ratings. Some new models of Fresnel Reflectors with Ray Tracing capabilities have begun to be tested and have initially proved to yield higher output than the standard version.[53]

Dish Stirling

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 (482–1,292 °F) and then used by a Stirling engine to generate power.[41] Parabolic-dish systems provide high solar-to-electric efficiency (between 31% and 32%), and their modular nature provides scalability. The Stirling Energy Systems (SES), United Sun Systems (USS) 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 world record for solar to electric efficiency was set at 31.25% by SES dishes at the National Solar Thermal Test Facility (NSTTF) in New Mexico on 31 January 2008, a cold, bright day.[54] According to its developer, Ripasso Energy, a Swedish firm, in 2015 its Dish Sterling system being tested in the Kalahari Desert in South Africa showed 34% efficiency.[55] The SES installation in Maricopa, Phoenix was the largest Stirling Dish power installation in the world until it was sold to United Sun Systems. Subsequently, larger parts of the installation have been moved to China as part of the huge energy demand.

Solar thermal enhanced oil recovery

Heat from the sun can be used to provide steam used to make heavy oil less viscous and easier to pump. Solar power tower and parabolic troughs can be used to provide the steam which is used directly so no generators are required and no electricity is produced. Solar thermal enhanced oil recovery can extend the life of oilfields with very thick oil which would not otherwise be economical to pump.[56]

CSP with thermal energy storage

In a CSP plant that includes storage, the solar energy is first used to heat the molten salt or synthetic oil which is stored providing thermal/heat energy at high temperature in insulated tanks.[57][58] Later the hot molten salt (or oil) is used in a steam generator to produce steam to generate electricity by steam turbo generator as per requirement.[59] Thus solar energy which is available in daylight only is used to generate electricity round the clock on demand as a load following power plant or solar peaker plant.[60][61] The thermal storage capacity is indicated in hours of power generation at nameplate capacity. Unlike solar PV or CSP without storage, the power generation from solar thermal storage plants is dispatchable and self-sustainable similar to coal/gas-fired power plants, but without the pollution.[62] CSP with thermal energy storage plants can also be used as cogeneration plants to supply both electricity and process steam round the clock. As of December 2018, CSP with thermal energy storage plants generation cost have ranged between 5 c € / kWh and 7 c € / kWh depending on good to medium solar radiation received at a location.[63] Unlike solar PV plants, CSP with thermal energy storage plants can also be used economically round the clock to produce only process steam replacing pollution emitting fossil fuels. CSP plant can also be integrated with solar PV for better synergy.[64][65][66]

CSP with thermal storage systems are also available using Brayton cycle with air instead of steam for generating electricity and/or steam round the clock. These CSP plants are equipped with gas turbine to generate electricity.[67] These are also small in capacity (<0.4 MW) with flexibility to install in few acres area.[67] Waste heat from the power plant can also be used for process steam generation and HVAC needs.[68] In case land availability is not a limitation, any number of these modules can be installed up to 1000 MW with RAMS and cost advantage since the per MW cost of these units are cheaper than bigger size solar thermal stations.[69]

Centralized district heating round the clock is also feasible with concentrated solar thermal storage plants.[70]

Deployment around the world

1,000
2,000
3,000
4,000
5,000
6,000
7,000
1984
1990
1995
2000
2005
2010
2015
Worldwide CSP capacity since 1984 in MWp
National CSP capacities in 2018 (MWp)
Spain 2,300 0
United States 1,738 0
South Africa 400 100
Morocco 380 200
India 225 0
China 210 200
United Arab Emirates 100 0
Saudi Arabia 50 50
Algeria 25 0
Egypt 20 0
Australia 12 0
Thailand 5 0
Source: REN21 Global Status Report, 2017 and 2018[71][72][8]

The commercial deployment of CSP plants started by 1984 in the US with the SEGS plants. The last SEGS plant was completed in 1990. From 1991 to 2005, no CSP plants were built anywhere in the world. Global installed CSP-capacity increased nearly tenfold between 2004 and 2013 and grew at an average of 50 percent per year during the last five of those years.[73]:51 In 2013, worldwide installed capacity increased by 36% or nearly 0.9 gigawatt (GW) to more than 3.4 GW. Spain and the United States remained the global leaders, while the number of countries with installed CSP were growing but the rapid decrease in price of PV solar, policy changes and the global financial crisis stopped most development in these countries. 2014 was the best year for CSP but was followed by a rapid decline with only one major plant completed in the world in 2016. There is a notable trend towards developing countries and regions with high solar radiation with several large plants under construction in 2017.

Worldwide Concentrated Solar Power (MWp)
Year 1984 1985 1989 1990 1991-2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019
Installed 14 60 200 80 0 1 74 55 179 307 629 803 872 925 420 110 100 550 381
Cumulative 14 74 274 354 354 355 429 484 663 969 1,598 2,553 3,425 4,335 4,705 4,815 4,915 5,465 6,451[74]
Sources: REN21[71][75]:146[73] :51[72]  · CSP-world.com[76] · IRENA[77] · HeliosCSP[8]

Efficiency

The efficiency of a concentrating solar power system will depend on the technology used to convert the solar power to electrical energy, the operating temperature of the receiver and the heat rejection, thermal losses in the system, and the presence or absence of other system losses; in addition to the conversion efficiency, the optical system which concentrates the sunlight will also add additional losses.

Real-world systems claim a maximum conversion efficiency of 23-35% for "power tower" type systems, operating at temperatures from 250 to 565 °C, with the higher efficiency number assuming a combined cycle turbine. Dish Stirling systems, operating at temperatures of 550-750 °C, claim an efficiency of about 30%.[78] Due to variation in sun incidence during the day, the average conversion efficiency achieved is not equal to these maximum efficiencies, and the net annual solar-to- electricity efficiencies are 7-20% for pilot power tower systems, and 12-25% for demonstration-scale Stirling dish systems.[78]

Theory

The maximum conversion efficiency of any thermal to electrical energy system is given by the Carnot efficiency, which represents a theoretical limit to the efficiency that can be achieved by any system, set by the laws of thermodynamics. Real-world systems do not achieve the Carnot efficiency.

The conversion efficiency ${\displaystyle \eta }$ of the incident solar radiation into mechanical work depends on the thermal radiation properties of the solar receiver and on the heat engine (e.g. steam turbine). Solar irradiation is first converted into heat by the solar receiver with the efficiency ${\displaystyle \eta _{Receiver}}$ and subsequently the heat is converted into mechanical energy by the heat engine with the efficiency ${\displaystyle \eta _{mechanical}}$, using Carnot's principle.[79][80] The mechanical energy is then converted into electrical energy by a generator. For a solar receiver with a mechanical converter (e.g., a turbine), the overall conversion efficiency can be defined as follows:

${\displaystyle \eta =\eta _{\mathrm {optics} }\cdot \eta _{\mathrm {receiver} }\cdot \eta _{\mathrm {mechanical} }\cdot \eta _{\mathrm {generator} }}$

where ${\displaystyle \eta _{\mathrm {optics} }}$ represents the fraction of incident light concentrated onto the receiver, ${\displaystyle \eta _{\mathrm {receiver} }}$ the fraction of light incident on the receiver that is converted into heat energy, ${\displaystyle \eta _{\mathrm {mechanical} }}$ the efficiency of conversion of heat energy into mechanical energy, and ${\displaystyle \eta _{\mathrm {generator} }}$ the efficiency of converting the mechanical energy into electrical power.

${\displaystyle \eta _{\mathrm {receiver} }}$ is:

${\displaystyle \eta _{\mathrm {receiver} }={\frac {Q_{\mathrm {absorbed} }-Q_{\mathrm {lost} }}{Q_{\mathrm {incident} }}}}$
with ${\displaystyle Q_{\mathrm {incident} }}$, ${\displaystyle Q_{\mathrm {absorbed} }}$, ${\displaystyle Q_{\mathrm {lost} }}$ respectively the incoming solar flux and the fluxes absorbed and lost by the system solar receiver.

The conversion efficiency ${\displaystyle \eta _{\mathrm {mechanical} }}$ is at most the Carnot efficiency, which is determined by the temperature of the receiver ${\displaystyle T_{H}}$ and the temperature of the heat rejection ("heat sink temperature") ${\displaystyle T^{0}}$,

${\displaystyle \eta _{\mathrm {Carnot} }=1-{\frac {T^{0}}{T_{H}}}}$

The real-world efficiencies of typical engines achieve 50% to at most 70% of the Carnot efficiency due to losses such as heat loss and windage in the moving parts.

Ideal case

For a solar flux ${\displaystyle I}$ (e.g. ${\displaystyle I=1000\,\mathrm {W/m^{2}} }$) concentrated ${\displaystyle C}$ times with an efficiency ${\displaystyle \eta _{Optics}}$ on the system solar receiver with a collecting area ${\displaystyle A}$ and an absorptivity ${\displaystyle \alpha }$:

${\displaystyle Q_{\mathrm {solar} }=ICA}$,
${\displaystyle Q_{\mathrm {absorbed} }=\eta _{\mathrm {optics} }\alpha Q_{\mathrm {solar} }}$,

For simplicity's sake, one can assume that the losses are only radiative ones (a fair assumption for high temperatures), thus for a reradiating area A and an emissivity ${\displaystyle \epsilon }$ applying the Stefan-Boltzmann law yields:

${\displaystyle Q_{\mathrm {lost} }=A\epsilon \sigma T_{H}^{4}}$

Simplifying these equations by considering perfect optics (${\displaystyle \eta _{\mathrm {Optics} }}$ = 1) and without considering the ultimate conversion step into electricity by a generator, collecting and reradiating areas equal and maximum absorptivity and emissivity (${\displaystyle \alpha }$ = 1, ${\displaystyle \epsilon }$ = 1) then substituting in the first equation gives

${\displaystyle \eta =\left(1-{\frac {\sigma T_{H}^{4}}{IC}}\right)\cdot \left(1-{\frac {T^{0}}{T_{H}}}\right)}$

The graph shows that the overall efficiency does not increase steadily with the receiver's temperature. Although the heat engine's efficiency (Carnot) increases with higher temperature, the receiver's efficiency does not. On the contrary, the receiver's efficiency is decreasing, as the amount of energy it cannot absorb (Qlost) grows by the fourth power as a function of temperature. Hence, there is a maximum reachable temperature. When the receiver efficiency is null (blue curve on the figure below), Tmax is: ${\displaystyle T_{\mathrm {max} }=\left({\frac {IC}{\sigma }}\right)^{0.25}}$

There is a temperature Topt for which the efficiency is maximum, i.e. when the efficiency derivative relative to the receiver temperature is null:

${\displaystyle {\frac {d\eta }{dT_{H}}}(T_{\mathrm {opt} })=0}$

Consequently, this leads us to the following equation:

${\displaystyle T_{opt}^{5}-(0.75T^{0})T_{\mathrm {opt} }^{4}-{\frac {T^{0}IC}{4\sigma }}=0}$

Solving this equation numerically allows us to obtain the optimum process temperature according to the solar concentration ratio ${\displaystyle C}$ (red curve on the figure below)

 C Tmax Topt 500 1000 5000 10000 45000 (max. for Earth) 1720 2050 3060 3640 5300 970 1100 1500 1720 2310

Theoretical efficiencies aside, real-world experience of CSP reveals a 25%–60% shortfall in projected production, a good part of which is due to the practical Carnot cycle losses not included in the above analysis.

Cost and value of CSP

Eventhough overall deployment of CSP remains limited the levelized cost of power from commercial scale plants has decreased significantly in recent years. With a learning rate estimated at arround 20% cost reduction of every doubeling in capacity [81] the cost were approaching the upper end of the fossile fuel cost range at the beginning of the 2020s driven be support schemes in several countries, including Spain, the USA, Morocco, South Africa, China, and the UAE:

In markets around the world CSP is facing a difficult situation and deployment has slowed down considerably as most of the above mentioned markets have cancelled their support,[82] as the technology turned out to be more expensive on a per kWH basis than solar PV and wind power. However, the value of CSP is today the combination with Thermal Energy Storage(TES) that makes the plants dispatchable and a good addition for power systems rich in fluctuating generation from PV and wind. Power from CSP with TES is expected to remain cheaper than PV with lithium batteries for storage durations above 4 hours per day [83] allowing, for example, cheap solar base-load that could be interesting for energy intensive processes such as smelting or hydrolysis.

Incentives and Markets

Spain

In 2008 Spain launched the first commercial scale CSP market in Europe. Until 2012, solar-thermal electricity generation was initially eligible for feed-in tariff payments (art. 2 RD 661/2007) - leading to the creation of the largest CSP fleet in the world which at 2.3 GW of installed capacity contributes about 5TW of power to the Spanish grid every year.[84] The initial requirments for plants in the FiT were:

• Systems registered in the register of systems prior to 29 September 2008: 50 MW for solar-thermal systems.
• Systems registered after 29 September 2008 (PV only).

The capacity limits for the different system types were re-defined during the review of the application conditions every quarter (art. 5 RD 1578/2008, Annex III RD 1578/2008). Prior to the end of an application period, the market caps specified for each system type are published on the website of the Ministry of Industry, Tourism and Trade (art. 5 RD 1578/2008).[85] Because of cost concerns Spain has halted acceptance of new projects for the feed-in-tariff on 27 January 2012 [86][87] Allready accepted pojects were affected by a 6% "solar-tax" on feed-in-tariffs, effectively reducing the feed-in-tariff.[88]

After a lost decade for CSP in Europe, Spain announced it its National Energy and Climate Plan the intention of adding 5GW of CSP capacity between 2021 and 2030 [89]. Towards this end bi-annual auctions of 200 MW of CSP capacity starting in 2021 are expected, but details are not yet know [90].

Australia

So far no sommercial scale CSP project has been commissioned in Australia, but several projects were suggeseted. In 2017 now bancrupt American CSP developer SolarReserve got awarded a PPA to realize the 150MW Aurora Solar Thermal Power Project in South Australia at a record low rate of just AUD78/MWh or close to USD0.06/kWh [91]. Unfortunatly the company failed to secure financing and the project got cancelled. Another promissing application for CSP in Australia are mines that need 24/7 electricity but often have no grid connection. Vast Solar a startup company aiming to commercialze a novel modular third generation CSP design [92] [93] is looking to start construction of a 50MW combines CSP and PV facility in Mt. Isa of North-West Queensland in 2021 [94].

At the federal level, under the Large-scale Renewable Energy Target (LRET), in operation under the Renewable Energy Electricity Act 2000, large scale solar thermal electricity generation from accredited RET power stations may be entitled to create large-scale generation certificates (LGCs). These certificates can then be sold and transferred to liable entities (usually electricity retailers) to meet their obligations under this tradeable certificates scheme. However, as this legislation is technology neutral in its operation, it tends to favour more established RE technologies with a lower levelised cost of generation, such as large scale onshore wind, rather than solar thermal and CSP.[95] At State level, renewable energy feed-in laws typically are capped by maximum generation capacity in kWp, and are open only to micro or medium scale generation and in a number of instances are only open to solar PV (photovoltaic) generation. This means that larger scale CSP projects would not be eligible for payment for feed-in incentives in many of the State and Territory jurisdictions.

China

In 2016 China announced its intention to build a batch of 20 technologically diverse CSP demonstration projects in the context of the 13th Five-Year Plan, with the intention of building up an internationally competitive CSP industry.[96] Since the first plants were completed in 2018, the generated electricity from the plants with thermal storage is supported with an administratively set FiT of RMB 1.5 per kWh.[97] At the end 2020 China operated a toal of 545 MW in 12 CSP plants,[98] seven plants (320 MW) are molten-salt towers another two plants (150MW) use the proven Eurotrough 150 parabolic trough desgin,[99] three plants (75 MW) use liner fresnel collectors. Plans to build a second batch of demonstration projects where never enacted and further technology specific support for CSP in the upcoming 14th Five-Year Plan is unknown. Current support is set for remaining projects from the demonstration batch will run out at the end of 2021.[100]

India

In March 2020, SECI called for 5000 MW tenders which can be combination of Solar PV, Solar thermal with storage and Coal based power (minimum 51% from renewable sources) to supply round the clock power at minimum 80% yearly availability.[101][102]

Future

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 worldwide to €92.5 billion in that time period.[103] Spain is the leader in concentrated solar power technology, with more than 50 government-approved projects in the works. Also, it exports its technology, further increasing the technology's stake in energy worldwide. Because the technology works best with areas of high insolation (solar radiation), experts predict the biggest growth in places like Africa, Mexico, and the southwest United States. It indicates that the thermal storage systems based in nitrates (calcium, potassium, sodium,...) will make the CSP plants more and more profitable. 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. The findings of the third part are shown in the table below:

Year Annual
Investment
Cumulative
Capacity
2015 €21 billion 4,755 MW
2050 €174 billion 1,500,000 MW

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 €0.23–0.15/kWh to €0.14–0.10/kWh.[103]

The European Union looked into developing a €400 billion (US$774 billion) network of solar power plants based in the Sahara region using CSP technology to be known as Desertec, to create "a new carbon-free network linking Europe, the Middle East and North Africa". The plan was backed mainly by German industrialists and predicted production of 15% of Europe's power by 2050. Morocco was a major partner in Desertec and as it has barely 1% of the electricity consumption of the EU, it could produce more than enough energy for the entire country with a large energy surplus to deliver to Europe.[104] Algeria has the biggest area of desert, and private Algerian firm Cevital signed up for Desertec.[104] With its wide desert (the highest CSP potential in the Mediterranean and Middle East regions ~ about 170 TWh/year) and its strategic geographical location near Europe, Algeria is one of the key countries to ensure the success of Desertec project. Moreover, with the abundant natural-gas reserve in the Algerian desert, this will strengthen the technical potential of Algeria in acquiring Solar-Gas Hybrid Power Plants for 24-hour electricity generation. Most of the participants pulled out of the effort at the end of 2014. Experience with first-of-a-kind CSP plants in the USA was mixed. Solana in Arizona, and Ivanpah in Nevada indicate large production shortfalls in electricity generation between 25% and 40% in the first years of operation. Producers blame clouds and stormy weather, but critics seem to think there are technological issues. These problems are causing utilities to pay inflated prices for wholesale electricity, and threaten the long-term viability of the technology. As photovoltaic costs continue to plummet, many think CSP has a limited future in utility-scale electricity production.[105]. In other countries expecially Spain and South Africa CSP plants have met their designed parameters [106] CSP has other uses than electricity. Researchers are investigating solar thermal reactors for the production of solar fuels, making solar a fully transportable form of energy in the future. These researchers use the solar heat of CSP as a catalyst for thermochemistry to break apart molecules of H2O, to create hydrogen (H2) from solar energy with no carbon emissions.[107] By splitting both H2O and CO2, other much-used hydrocarbons – for example, the jet fuel used to fly commercial airplanes – could also be created with solar energy rather than from fossil fuels.[108] Very large scale solar power plants There have been several proposals for gigawatt size, very-large-scale solar power plants.[109] They include the Euro-Mediterranean Desertec proposal and Project Helios in Greece (10 GW), both now canceled. A 2003 study concluded that the world could generate 2,357,840 TWh each year from very large scale solar power plants using 1% of each of the world's deserts. Total consumption worldwide was 15,223 TWh/year[110] (in 2003). The gigawatt size projects would have been arrays of standard-sized single plants. In 2012, the BLM made available 97,921,069 acres (39,627,251 hectares) of land in the southwestern United States for solar projects, enough for between 10,000 and 20,000 GW.[111] The largest single plant in operation is the 510 MW Noor Solar Power Station. In 2022 the 700 MW CSP 4th phase of the 5GW Mohammed bin Rashid Al Maktoum Solar Park in Dubai will become the largest solar complex featuring CSP. Suitable sites The locations with highest direct irradiance are dry, at high altitude, and located in the tropics. These locations have a higher potential for CSP than areas with less sun. Abandoned opencast mines, moderate hill slopes and crater depressions may be advantageous in the case of power tower CSP as the power tower can be located on the ground integral with the molten salt storage tank.[112] Environmental effects CSP has a number of environmental effects, particularly on water use, land use and the use of hazardous materials.[113] Water is generally used for cooling and to clean mirrors. Cleaning agents (hydrochloric acid, sulfuric acid, nitric acid, hydrogen fluoride, 1,1,1-trichloroethane, acetone, and others) are also used for semiconductor surface cleaning. Some projects are looking into various approaches to reduce the water and cleaning agents use, including the use of barriers, non-stick coatings on mirrors, water misting systems, and others.[114] Effects on wildlife Dead warbler burned in mid-air by solar thermal power plant Insects can be attracted to the bright light caused by concentrated solar technology, and as a result birds that hunt them can be killed by being burned if they fly near the point where light is being focused. This can also affect raptors who hunt the birds.[115][116][117][118] Federal wildlife officials were quoted by opponents as calling the Ivanpah power towers "mega traps" for wildlife.[119][120][121] According to rigorous reporting, in over six months, 133 singed birds were counted.[122] By focusing no more than four mirrors on any one place in the air during standby, at Crescent Dunes Solar Energy Project, in three months, the death rate dropped to zero.[123] Other than in the US, no bird deaths have been reported at CSP plants internationally. See also References 1. ^ "How CSP Works: Tower, Trough, Fresnel or Dish". SolarPACES. 12 June 2018. Retrieved 29 November 2019. 2. ^ Boerema, Nicholas; Morrison, Graham; Taylor, Robert; Rosengarten, Gary (1 November 2013). "High temperature solar thermal central-receiver billboard design". Solar Energy. 97: 356–368. Bibcode:2013SoEn...97..356B. doi:10.1016/j.solener.2013.09.008. 3. ^ Law, Edward W.; Prasad, Abhnil A.; Kay, Merlinde; Taylor, Robert A. (1 October 2014). "Direct normal irradiance forecasting and its application to concentrated solar thermal output forecasting – A review". Solar Energy. 108: 287–307. Bibcode:2014SoEn..108..287L. doi:10.1016/j.solener.2014.07.008. 4. ^ Law, Edward W.; Kay, Merlinde; Taylor, Robert A. (1 February 2016). "Calculating the financial value of a concentrated solar thermal plant operated using direct normal irradiance forecasts". Solar Energy. 125: 267–281. Bibcode:2016SoEn..125..267L. doi:10.1016/j.solener.2015.12.031. 5. ^ "Sunshine to Petrol" (PDF). Sandia National Laboratories. Archived from the original (PDF) on 19 February 2013. Retrieved 11 April 2013. 6. ^ "Integrated Solar Thermochemical Reaction System". U.S. Department of Energy. Retrieved 11 April 2013. 7. ^ Matthew L. Wald (10 April 2013). "New Solar Process Gets More Out of Natural Gas". The New York Times. Retrieved 11 April 2013. 8. ^ a b c 9. ^ Janet L. Sawin & Eric Martinot (29 September 2011). "Renewables Bounced Back in 2010, Finds REN21 Global Report". Renewable Energy World. Archived from the original on 2 November 2011. 10. ^ Louis Boisgibault, Fahad Al Kabbani (2020): Energy Transition in Metropolises, Rural Areas and Deserts. Wiley - ISTE. (Energy series) ISBN 9781786304995. 11. ^ "New Chance for US CSP? California Outlaws Gas-Fired Peaker Plants". Retrieved 23 February 2018. 12. ^ Deign, Jason (24 June 2019). "Concentrated Solar Power Quietly Makes a Comeback". www.greentechmedia.com. 13. ^ "As Concentrated Solar Power bids fall to record lows, prices seen diverging between different regions". Retrieved 23 February 2018. 14. ^ Chris Clarke. "Are Solar Power Towers Doomed in California?". KCET. 15. ^ "After the Desertec hype: is concentrating solar power still alive?". Retrieved 24 September 2017. 16. ^ "CSP Doesn't Compete With PV – it Competes with Gas". Retrieved 4 March 2018. 17. ^ "Concentrated Solar Power Costs Fell 46% From 2010–2018". Retrieved 3 June 2019. 18. ^ "UAE's push on concentrated solar power should open eyes across world". Retrieved 29 October 2017. 19. ^ "Concentrated Solar Power Dropped 50% in Six Months". Retrieved 31 October 2017. 20. ^ Reuters (20 September 2017). "ACWA Power scales up tower-trough design to set record-low CSP price". New Energy Update / CSP Today. Retrieved 29 November 2019. 21. ^ "SolarReserve Bids CSP Under 5 Cents in Chilean Auction". Retrieved 29 October 2017. 22. ^ "SolarReserve Bids 24-Hour Solar At 6.3 Cents In Chile". CleanTechnica. 13 March 2017. Retrieved 14 March 2017. 23. ^ Thomas W. Africa (1975). "Archimedes through the Looking Glass". The Classical World. 68 (5): 305–308. doi:10.2307/4348211. JSTOR 4348211. 24. ^ Ken Butti, John Perlin (1980) A Golden Thread: 2500 Years of Solar Architecture and Technology, Cheshire Books, pp. 66–100, ISBN 0442240058. 25. ^ Meyer, CM. "From troughs to triumph: SEGS and gas". Eepublishers.co.za. Archived from the original on 7 August 2011. Retrieved 22 April 2013. 26. ^ Cutler J. Cleveland (23 August 2008). Shuman, Frank. Encyclopedia of Earth. 27. ^ Paul Collins (Spring 2002) The Beautiful Possibility. Cabinet Magazine, Issue 6. 28. ^ "A New Invention To Harness The Sun" Popular Science, November 1929 29. ^ Ken Butti, John Perlin (1980) A Golden Thread: 2500 Years of Solar Architecture and Technology, Cheshire Books, p. 68, ISBN 0442240058. 30. ^ "Molten Salt Storage". large.stanford.edu. Retrieved 31 March 2019. 31. ^ "Ivanpah Solar Project Faces Risk of Default on PG&E Contracts". KQED News. Archived from the original on 25 March 2016. 32. ^ 33. ^ "Why Concentrating Solar Power Needs Storage to Survive". Retrieved 21 November 2017. 34. ^ Types of solar thermal CSP plants. Tomkonrad.wordpress.com. Retrieved on 22 April 2013. 35. ^ a b Chaves, Julio (2015). Introduction to Nonimaging Optics, Second Edition. CRC Press. ISBN 978-1482206739. 36. ^ a b Roland Winston, Juan C. Miñano, Pablo G. Benitez (2004) Nonimaging Optics, Academic Press, ISBN 978-0127597515. 37. ^ Norton, Brian (2013). Harnessing Solar Heat. Springer. ISBN 978-94-007-7275-5. 38. ^ New innovations in solar thermal. Popularmechanics.com (1 November 2008). Retrieved on 22 April 2013. 39. ^ Chandra, Yogender Pal (17 April 2017). "Numerical optimization and convective thermal loss analysis of improved solar parabolic trough collector receiver system with one sided thermal insulation". Solar Energy. 148: 36–48. Bibcode:2017SoEn..148...36C. doi:10.1016/j.solener.2017.02.051. 40. ^ Vignarooban, K.; Xinhai, Xu (2015). "Heat transfer fluids for concentrating solar power systems – A review". Applied Energy. 146: 383–396. doi:10.1016/j.apenergy.2015.01.125. 41. ^ a b c Christopher L. Martin; D. Yogi Goswami (2005). Solar energy pocket reference. Earthscan. p. 45. ISBN 978-1-84407-306-1. 42. ^ "Linear-focusing Concentrator Facilities: DCS, DISS, EUROTROUGH and LS3". Plataforma Solar de Almería. Archived from the original on 28 September 2007. Retrieved 29 September 2007. 43. ^ a b Deloitte Touche Tohmatsu Ltd, "Energy & Resources Predictions 2012", 2 November 2011 44. ^ Helman, "Oil from the sun", "Forbes", 25 April 2011 45. ^ Goossens, Ehren, "Chevron Uses Solar-Thermal Steam to Extract Oil in California", "Bloomberg", 3 October 2011 46. ^ 47. ^ "Ivanpah - World's Largest Solar Plant in California Desert". www.brightsourceenergy.com. 48. ^ "Electricity Data Browser". www.eia.gov. 49. ^ "Electricity Data Browser". www.eia.gov. 50. ^ "Electricity Data Browser". www.eia.gov. 51. ^ Compact CLFR. Physics.usyd.edu.au (12 June 2002). Retrieved on 22 April 2013. 52. ^ 53. ^ Abbas, R.; Muñoz-Antón, J.; Valdés, M.; Martínez-Val, J.M. (August 2013). "High concentration linear Fresnel reflectors". Energy Conversion and Management. 72: 60–68. doi:10.1016/j.enconman.2013.01.039. 54. ^ Sandia, Stirling Energy Systems set new world record for solar-to-grid conversion efficiency. Archived 19 February 2013 at the Wayback Machine Share.sandia.gov (12 February 2008). Retrieved on 22 April 2013. 55. ^ Jeffrey Barbee (13 May 2015). "Could this be the world's most efficient solar electricity system?". The Guardian. Retrieved 21 April 2017. 34% of the sun’s energy hitting the mirrors is converted directly to grid-available electric power 56. ^ "CSP EOR developer cuts costs on 1 GW Oman Concentrated Solar Power project". Retrieved 24 September 2017. 57. ^ "How CSP's Thermal Energy Storage Works - SolarPACES". SolarPACES. 10 September 2017. Retrieved 21 November 2017. 58. ^ "Molten salt energy storage". Archived from the original on 29 August 2017. Retrieved 22 August 2017. 59. ^ "The Latest in Thermal Energy Storage". Retrieved 22 August 2017. 60. ^ "Concentrating Solar Power Isn't Viable Without Storage, Say Experts". Retrieved 29 August 2017. 61. ^ "How Solar Peaker Plants Could Replace Gas Peakers". Retrieved 2 April 2018. 62. ^ "Aurora: What you should know about Port Augusta's solar power-tower". Retrieved 22 August 2017. 63. ^ "2018, the year in which the Concentrated Solar Power returned to shine". Retrieved 18 December 2018. 64. ^ "Controllable solar power – competitively priced for the first time in North Africa". Retrieved 7 June 2019. 65. ^ "Morocco Breaks New Record with 800 MW Midelt 1 CSP-PV at 7 Cents". Retrieved 7 June 2019. 66. ^ "Morocco Pioneers PV with Thermal Storage at 800 MW Midelt CSP Project". Retrieved 25 April 2020. 67. ^ a b "247Solar and Masen Ink Agreement for First Operational Next Generation Concentrated Solar Power Plant". Retrieved 31 August 2019. 68. ^ "247Solar modular & scalable concentrated solar power tech to be marketed to mining by ROST". Retrieved 31 October 2019. 69. ^ "Capex of modular Concentrated Solar Power plants could halve if 1 GW deployed". Retrieved 31 October 2019. 70. ^ "Tibet's first solar district heating plant". Retrieved 20 December 2019. 71. ^ a b Renewables Global Status Report, REN21, 2017 72. ^ a b Renewables 2017: Global Status Report, REN21, 2018 73. ^ a b REN21 (2014). Renewables 2014: Global Status Report (PDF). ISBN 978-3-9815934-2-6. Archived from the original (PDF) on 15 September 2014. Retrieved 14 September 2014. 74. ^ "Concentrated solar power had a global total installed capacity of 6,451 MW in 2019". Retrieved 3 February 2020. 75. ^ REN21 (2016). Renewables 2016: Global Status Report (PDF). ISBN 978-3-9818107-0-7. 76. ^ "CSP Facts & Figures". csp-world.com. June 2012. Archived from the original on 29 April 2013. Retrieved 22 April 2013. 77. ^ "Concentrating Solar Power" (PDF). International Renewable Energy Agency. June 2012. p. 11. Archived from the original (PDF) on 22 November 2012. Retrieved 9 September 2012. 78. ^ a b International Renewable Energy Agency, "Table 2.1: Comparison of different CSP Technologies", in Concentrating Solar Power, Volume 1: Power Sector, RENEWABLE ENERGY TECHNOLOGIES: COST ANALYSIS SERIES, June 2012, p. 10. Retrieved 23 May 2019. 79. ^ E. A. Fletcher (2001). "Solar thermal processing: A review". Journal of Solar Energy Engineering. 123 (2): 63. doi:10.1115/1.1349552. 80. ^ Aldo Steinfeld & Robert Palumbo (2001). "Solar Thermochemical Process Technology" (PDF). Encyclopedia of Physical Science & Technology, R.A. Meyers Ed. Academic Press. 15: 237–256. Archived from the original (PDF) on 19 July 2014. 81. ^ Johan Lilliestam; et al. "Empirically observed learning rates for concentrating solar power and their responses to regime change". Nature energy. 2 (17094). doi:10.1038/nenergy.2017.94. 82. ^ Johan Lilliestam; et al. "The near- to mid-term outlook for concentrating solar power: mostly cloudy, chance of sun". Energy Sources, Part B. doi:10.1080/15567249.2020.1773580. 83. ^ Franziska Schöniger; et al. "Making the sun shine at night: comparing the cost of dispatchable concentrating solar power and photovoltaics with storage". Energy Sources, Part B. doi:10.1080/15567249.2020.1843565. 84. ^ [1] Generation from Spain’s Existing 2.3 GW of CSP Showing Steady Annual Increases. 85. ^ Feed-in tariff (Régimen Especial). res-legal.de (12 December 2011). 86. ^ Spanish government halts PV, CSP feed-in tariffs Archived 5 August 2012 at the Wayback Machine. Solarserver.com (30 January 2012). Retrieved on 22 April 2013. 87. ^ Spain Halts Feed-in-Tariffs for Renewable Energy. Instituteforenergyresearch.org (9 April 2012). Retrieved on 22 April 2013. 88. ^ Spain introduces 6% energy tax. Evwind.es (14 September 2012). Retrieved on 22 April 2013. 89. ^ 90. ^ "El MITECO aprueba la orden para iniciar el calendario de subastas". www.miteco.gob.es. 91. ^ Kraemer, S. (2017), SolarReserve Breaks CSP Price Record with 6 Cent Contract, SolarPACES [2] 92. ^ Kraemer, S. (2019) Sodium-based Vast Solar Combines the Best of Trough & Tower CSP to Win our Innovation Award, SolarPACES [3] 93. ^ New Energy Update (2019) CSP mini tower developer predicts costs below$50/MWh [4]
94. ^ PV magazine (2020) Vast Solar eyes \$600 million solar hybrid plant for Mount Isa [5]
95. ^ A Dangerous Obsession with Least Cost? Climate Change, Renewable Energy Law and Emissions Trading Prest, J. (2009) in Climate Change Law: Comparative, Contractual and Regulatory Considerations, W. Gumley & T. Daya-Winterbottom (eds.) Lawbook Company, ISBN 0455226342
96. ^ The dragon awakens: Will China save or conquer concentrating solar power? https://doi.org/10.1063/1.5117648
97. ^ "2018 Review: China concentrated solar power pilot projects' development". Retrieved 15 January 2019.
98. ^ Johan Lilliestam, Richard Thonig, Alina Gilmanova, & Chuncheng Zang. (2020). CSP.guru (Version 2020-07-01) [Data set]. Zenodo. http://doi.org/10.5281/zenodo.4297966
99. ^ SolarPACES (2021), EuroTrough Helped Cut Ramp-Up Time of China’s 100 MW Urat CSP https://www.solarpaces.org/eurotrough-cut-ramp-up-in-china-100-mw-urat-csp%E2%80%A8
100. ^ HeliosCSP (2020) China mulls withdrawal of subsidies for concentrated solar power (CSP) and offshore wind energy in 2021 http://helioscsp.com/china-mulls-withdrawal-of-subsidies-for-concentrated-solar-power-csp-and-offshore-wind-energy-in-2021/
101. ^ "SECI Issues Tender for 5 GW of Round-the-Clock Renewable Power Bundled with Thermal". Retrieved 29 March 2020.
102. ^ "SECI Invites EoI to Purchase Power for Blending with Renewable Sources". Retrieved 29 January 2020.
103. ^ a b
104. ^ a b Tom Pfeiffer (23 August 2009) Europe's Saharan power plan: miracle or mirage? Reuters
105. ^ Cassandra Sweet (13 June 2015). "High-Tech Solar Projects Fail to Deliver". WSJ.
106. ^ Kraemer, S. (2020) In South Africa and Spain, CSP is Meeting or Exceeding Projected Operation Targets https://www.solarpaces.org/in-south-africa-and-spain-csp-is-meeting-or-exceeding-projected-operation-targets/
107. ^ Kraemer, Susan (21 December 2017). "CSP is the Most Efficient Renewable to Split Water for Hydrogen". SolarPACES.org. Retrieved 3 August 2018.
108. ^ EurekAlert! (15 November 2017). "Desert solar to fuel centuries of air travel". EurekAlert!. Retrieved 3 August 2018.
109. ^ "The Sahara: a solar battery for Europe?". Retrieved 21 April 2018.
110. ^
111. ^ Solar Resource Data and Maps. Solareis.anl.gov. Retrieved on 22 April 2013.[dubious ]
112. ^ "Solar heads for the hills as tower technology turns upside down". Retrieved 21 August 2017.
113. ^
114. ^ Bolitho, Andrea (20 May 2019). "Smart cooling and cleaning for concentrated solar power plants". euronews.
115. ^ John Roach. "Burned Birds Become New Environmental Victims of the Energy Quest". NBC News.
116. ^ Michael Howard (20 August 2014). "Solar Thermal Plants Have a PR Problem, And That PR Problem Is Dead Birds Catching on Fire". Esquire.
117. ^
118. ^ "Associated Press News". bigstory.ap.org.
119. ^ "How a Solar Farm Set Hundreds of Birds Ablaze". Nature World News.
120. ^ "Full Page Reload". IEEE Spectrum: Technology, Engineering, and Science News.
121. ^ [6]
122. ^ "For the Birds: How Speculation Trumped Fact at Ivanpah". RenewableEnergyWorld.com. Retrieved 4 May 2015.
123. ^ "One Weird Trick Prevents Bird Deaths At Solar Towers". CleanTechnica.com. Retrieved 4 May 2015.