The first commercial parabolic trough collectors were established in 1912 in Egypt. The energy was used by a steam-driven pump to lift water from the Nile to irrigate fields (see www.sun1913.info).

In the 1980s, parabolic trough plants were built in a series of plants, to a total capacity of 354 MW for electricity generation in the southwestern U.S. (see en.wikipedia.org/wiki/Solar Energy Generating Systems). The collectors LS1, LS2 and LS3 were used. The evolution of the collectors showed increased size increased return on investment.

From 1998 - 2001 Flagsol worked on the development of the Euro Trough. The EuroTrough design conformed to the key geometric dimensions of the existing LS3. This had the advantage that the same mirror (RP3 Flabeg) and absorber tubes could be used (UVAC Solel). (see "Development of a Low Cost European Parabolic Trough Collector - EUROTrough, Final Report")


2003 a demonstration plant of the SKAL-ET collector with a length of 800m was put into operation by Flagsol and sbp. These are the more advanced successor to the Euro Trough, in which it was first realized, to drive 12 solar collector elements with a total length of around 150m with one drive unit (see Die Entwicklung des Parabolrinnen-Kollektors SKAL-ET150).

The development of the HelioTrough® collector began in 2005 with the goal to further refine the parabolic trough design, reducing the solar field cost and improving performance.


With the commissioning of "Nevada Solar One" in the United States in 2007 the next epoch of parabolic trough power plants has been started. The collector based on a space frame design with dimensions of the LS2 collector. (see de.wikipedia.org/wiki/Nevada_Solar_One).


The first parabolic trough power plant in Europe followed with Andasol 1 in 2008. In this plant, the SKAL-ET has been applied for the first time in a large commercial power plant, with the capability to deliver over 250 MW of thermal energy. In the short 4 years that followed around 2000 MWe of Parabolic Trough plants were taken in operation in Spain alone. (see www.protermosolar.com/).


It is beyond the scope of this website to continue this list. Therefore, back to HelioTrough® History:


  • Phase 1 (2005 2006): ANDA-NT

  • Phase 2 (2006 2008): ANDA-NTpro

  • Phase 3 (2008 2010): Advanced High Temperature Trough Collector
    • Partners: SMLLC, sbp, co-funded: DoE
    • Erection of demo-loop in SEGS plant, Test & Operation

  • Phase 4 (2010 2011): Commercial launch for planned Blythe project
    • Partners: STA, sbp
    • Building permission for California granted
    • Bankability confirmed by independent engineers

  • Phase 5 (2011 2013): Optimization and further cost reduction
    • Test facility for accelerated aging tests under real load conditions for Drive Pylon and bearings in operation
    • Evaluation of demo-loop is continued
    • Massreduction of steelstructure