- Written by AUSTELA
In 2013 we celebrate 100 years of concentrating solar thermal power generation (CST). At the beginning of 1913, the Al Meadi CST plant was commissioned in Cairo, Egypt. The Al Meadi plant was used to drive a 100hp irrigation pump producing 2,000m3.
At the beginning of the 20th century CST was competitive with coal in locations with good Direct Nominal Insolation (DNI) – solar resource - had 30% lower wear and tear, and was easier to operate than coal plants . The oil industry was still forming, with reserves still to be discovered in the Persian Gulf.
Designed by American Frank Shuman, the Al Meadi CST plant used 5 parabolic trough collectors (each 13 feet wide and 204 feet long) to generate up to 250°C saturated steam . Al Meadi did not use thermal oil, but direct steam generation, a technology being rediscovered today to increase the efficiency and lower environmental and capital costs of parabolic trough plants. Integrated hot water storage allowed the Al Meadi system to continue operating into the evening, demonstrating for the first time the benefits of CST with thermal energy storage . The British and Germans governments planned similar CST units to provide energy for their colonies .
The beginning of World War I paused these plans and accelerated the development of fossil fuel technologies; transportability of fuel became vital. After the war, vast and easily accessed oil reserves were discovered in Iraq and elsewhere, and industry embraced oil's convenience and tradability. Coal mining and coal-fired power production technologies developed rapidly. The Al Meadi plant was eventually dismantled.
The Al Meadi plant demonstrates well the inherent benefits of CST technologies in regions with good solar resource – low operating cost, no fuel requirement, and thermal energy storage to provide power after the sun has set.
The Al Meari story also also illustrates the value of moving a technology along the learning curve. At the beginning of the 20th century coal mining and capabilities for design and construction of coal fired power stations was limited. In the intervening 100 years, thousands of GWs of coal-fired electricity were constructed, industrial expertise and scale expanded and cost of coal-fired generation fell dramatically. The Al Meadi plant, competitive with coal and oil in 1913, was overtaken by fossil-fuel technologies.
Today CST has around 2GW installed plant capacity globally, and despite this comparatively small capacity in terms of today's global energy infrastructure, costs already decreased significantly and are expected to further decrease by 17-40% by 2020 . CST is moving rapidly along the learning curve and new technologies and plants are continually coming online.
As the world turns to alternatives to coal and oil use, the inherent benefits and value of CSP, demonstrated by the Al Meadi plant 100 years ago, are once again proving their relevance and value in the modern context as the demand for dispatchable renewable energy increases.
Signs are promising that at the beginning of the 21th century, CST is carving out a significant, permanent role in global energy supply.
Figure 1: View of the complete Al Meadi pumping station 
Figure 2: Al Meadi Parabolic trough arrangement 
Figure 3: Al Meadi Parabolic trough detail 
 L. Stinnesbeck, "Sonnenkraftmaschinen," Keller's Monatsblätter, vol. 3, No.1, Bergstadtverlag, Breslau, pp. 171–174, Nov-1914.
 New York Times, "American Inventor Uses Egypt's Sun for Power," New York, 02-Jul-1916.
 IRENA, "Renewable Energy Technologies: Cost analysis Series Volume 1 Issue 2/5 Concentrating Solar Power," Abu Dhabi, UAE, 2012.