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’s tower (the target). Concentrated solar thermal is seen as a viable solution for renewable, pollution-free energy.
Early designs used thesis Focused rays to heat water, and the resulting and used steam to power a turbine . Newer designs using liquid sodium have been demonstrated, and systems using molten salts (40% potassium nitrate , 60% sodium nitrate ). These working fluids have high heat capacity , which can be used to store energy before using turbines. These designs also allow to be generated when the sun is not shining.
Cost
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. [1] . Companies such as ESolar (backed by Google.org ) are continuing to develop low-cost, low-maintenance, mass producible devices that will reduce costs in the near future. [2] ESolar’s design uses large numbers of small mirrors (1.14 m²), which reduces the cost of installing concrete, steel, drilling and cranes.
Improvements in working fluid systems (hot / cold) designs for single tank thermocline systems with quartzite thermal fillers and oxygen blankets.
Design
- Some concentrating solar power towers are air-cooled instead of water-cooled, to avoid using limited desert water [3]
- Flat glass is used instead of the more expensive curved glass [3]
- Thermal storage to 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 that are coupled to generators which produce electricity
- Control systems to supervise and control all the plant activity including the heliostat array positions, alarms, other data acquisition and communication.
Generally, facilities use from 150 hectares (1,500,000 m 2 ) to 320 hectares (3,200,000 m 2 ).
Environmental concerns
There is such a wide range of solar concentrating facilities that can kill birds that fly over them. Near the center of the array temperatures can reach 550 o C which, with the solar flow itself, is enough to incinerate the birds to be more important to the eventual death of the bird. Workers at the Ivanpah solar power plant call these birds “streamers,” as they ignite in midair and plummet to the ground trailing smoke. During testing of the initial standby position for the heliostats, 115 birds were killed as they entered the concentrated solar flux. After adjusting to the position of a single point in the world, the following 6 months of operations, a total of 321 birds were killed. [4]Further bird fatalities can be avoided altogether by implementing a newly developed technique. [4]
The Ivanpah Solar Power Facility is classified as a greenhouse gas by the State of California because it has to burn fossil fuel for several hours so that it can quickly reach its operating temperature. [5]
Commercial applications
Recently, there has been a lot of interest in solar power technology, and there are several companies involved in planning, planning and building utility size power plants. This is an important step towards the ultimate goal of developing commercially viable plants. There are numerous examples of case studies of innovative solar power solutions. [6]
Examples of heliostat power plants
| Power plants | Installed capacity (MW) [ clarification needed ] |
Yearly production (GWh) [ clarification needed ] |
Country | Developer / Owner | Completed |
|---|---|---|---|---|---|
| Ivanpah Solar Power Facility | 392 (U / C) | 650 | United States | BrightSource Energy | 2013 |
| Crescent Dunes Solar Energy Project | 110 (U / C) | 500 | United States | SolarReserve | 2015 |
| PS20 solar power tower | 20 [7] | 44 | spain | Abengoa | 2009 |
| Gemasolar [8] | 17 | 100 | spain | Sener | 2011 |
| PS10 solar power tower | 11 [9] | 24 | spain | Abengoa | 2006 |
| Sierra SunTower | 5 [10] | United States | eSolar | 2009 | |
| Jülich Solar Tower | 1.5 [11] [12] | germany | 2008 | ||
| Greenway CSP Mersin Solar Tower Plant | 5 [13] | turkey | Greenway CSP | 2013 |
Novel applications
The Pit Power Tower [14] [15] combines a solar power tower and aero-electric power tower [16] 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 pit mine’s “stadium seating” helps overcome the blocking constraint.
As solar power towers are commonly used to drive turbines, and they tend to collect water, and they tend to collect water. 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.
See also
- Concentrated solar power
- Feed-in tariff
- List of concentrating solar thermal power companies
- List of Solar Thermal Power Stations
- National Solar Thermal Test Facility (NSTTF)
- Solar furnace
- Solar thermal energy
References
- Jump up^ John Lowry (2017). Avoiding Carbon Apocalypse Through Alternative Energy: Life After Fossil Fuels . Springer. p. 33.
- Jump up^ Google’s Goal: Renewable Energy Cheaper than Coal November 27, 2007
- ^ Jump up to:a b http://www.brightsourceenergy.com/technology/faqs/
- ^ Jump up to:a b Kraemer, Susan (16 April 2015). “One Weird Trick Prevents Bird Deaths At Solar Towers” . Clean Technica . Retrieved 20 February 2017.
- Jump up^ Danelski, David (21 October 2015). “It’s not easy being green: Ivanpah solar plant near Nevada burns much natural gas, making it a greenhouse gas emitter under state law” . Orange County Register . Santa Ana, California . Retrieved 14 September 2016 .
- Jump up^ SOLAR POWER IN THE NEWS
- Jump up^ Abengoa Solar Begins Operation of World’s Largest Solar Power Tower Plant
- Jump up^ Torresol Energy Commissions Gemasolar Power Plant in Spain
- Jump up^ First EU Commercial Concentrating Solar Power Tower Opens in Spain
- Jump up^ eSolar Ushers in New Era of Solar Energy with Unveiling of Sierra Power Plant
- Jump up^ RenewableEnergyWorld: Salt-Free Solar: CSP Tower Using Air
- Jump up^ DLR: Jülich solar tower power plant – research facility officially handed over to the operator
- Jump up^ [1]
- Jump up^ Pit Power Tower – Alternative Energy News Feb 2009
- Jump up^ Pit Power Tower US Patent
- Jump up^ Energy tower
