MD DC VA Solar Energy Industries Association

Concentrated Solar Power

14

Apr 14

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Solar power is becoming more and more competitive as a means of clean electricity generation due to the constant advancements in production and technologies. Manufacturing costs and conversion efficiency are one of the few barriers from making solar power a more commercially viable option for electricity generation than its competitors. However, concentrated solar power (CSP) systems represent a growing source of energy with the capacity to satisfy present and future electricity needs. [1] CSP is utilized in two forms, concentrated solar thermal (CST) and concentrated photovoltaic (CPV). Concentrated solar power technology uses mirrors or lenses with tracking systems to concentrate a large amount of sunlight onto a small area, setting new benchmarks in efficiency.

Concentrated solar thermal technology uses mirrors to reflect sunlight onto a receiver; this generates extreme heat in order to run a conventional solar thermoelectric power plant. There are four common forms of CST technologies which exist today, parabolic trough, solar power towers, dish/engine systems, and linear Fresnel reflectors. Parabolic troughs are the most mature and low-cost option of these technologies and so dominates the global market, accounting for 90% of CST plants. [2] This technology concentrates the sun’s rays using parabolic reflectors, heating a receiver pipe filled with fluid along the reflectors focal point in order to generate steam for power. The reflector rotates with the suns movement using a complex and expensive tracking system in order to optimize solar energy generation. [3] Solar Energy Generating Systems (SEGS) facility in California is the largest parabolic trough system in the world, with a generating capacity of 310MW. [4]

Concentrated photovoltaic (CPV) technology uses lenses to focus sunlight onto a small area of photovoltaic (PV) cells, which directly converts sunlight into electricity. By focusing sunlight onto a smaller area, less PV cells are required, allowing for the use of more expensive higher-efficiency multijunction PV cells which have reached efficiencies upwards of 44%. [5] Challenges facing this technology are the highly expensive tracking systems required to follow the suns movement, as well as cooling systems to deal with the intensified radiation. These extra expenses have seen a preference for conventional PV to date. However, achievements in technology dramatically reduced costs of CPV in 2013 with installation prices expected to continue to fall at an annual compound rate of 15% until 2017. Reduced costs and greater efficiency has seen this technology employed globally as a viable option for large scale electricity generation with worldwide installations expected to skyrocket 750% between now and 2020. [6]

Both CST and CPV have the potential to provide a clean and renewable energy future as developments are making these technologies more cost competitive with that of fossil fuels. This, along with growing public awareness and government incentives will only increase the role solar energy plays in global electricity generation.

 

Sources

“http://ww.ecogreengroup.org/uploads/ConcentratingSolarPower_greeneconomy_Ch4.pdf”.
“http://web.archive.org/web/20111102183605/http://www.renewableenergyworld.com/rea/news/article/2011/09/renewables-bounced-back-in-2010-finds-ren21-global-report”.
“http://energy.gov/eere/sunshot/concentrating-solar-power”.
“http://www.nexteraenergyresources.com/content/where/portfolio/pdf/segs.pdf”.
“http://www.nrel.gov/docs/fy13osti/43208.pdf”.
“http://www.pv-magazine.com/news/details/beitrag/concentrated-pv-solar-set-to-boom_100013699/#axzz2yQ1GJJnk”.

 

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