HelioTrough – New Giant Collector Captures even more Sun than Planned

Dr. Mark Schmitz, Head of Research & Development, TSK Flagsol Engineering GmbH

I came to Flagsol GmbH in September 2010 after ten years in research in the field of solar towers at the German Aerospace Center and the Solar-Institut Jülich. The prospect of using my ideas and experience at the Solar Millennium Group, which roused solar-thermal power plants from a deep slumber, was all too enticing!

I found a team of ten young, dedicated engineers with whom I would be in an ideal position to realize my goals for the upcoming research and development work: experts in process and software development and classic mechanical engineers complement each other here.

Our most important task at the moment is testing the new HelioTrough collector, which has been undergoing a test run in California since the end of 2009. Altogether 40 collector elements each measuring 20 meters in length and just under seven meters in width are turned towards the sun. With up to ten elements in a collector unit that means 1,260 m² which are moved with high precision by only one power train. This is an area more than 50 percent larger than the preceding collector Skal-ET. This size also presented a challenge, as large spans usually also cause significant deformations due to their own weight and the wind, leading to optical losses, although this can be prevented by a continuous mirror surface.

We collect new measuring data every day at the test plant. The first analyses produced a surprise; the volume of energy supplied by the collector exceeds even the high expectations that we had calculated into our preliminary analyses. To my knowledge, this makes it the most efficient collector on the market. At the same time, it is very assembly- and maintenance-friendly due to its heavily reduced design. This makes it ideal for use at the Blythe power plant, especially since its design from the first draft on took the requirements of serial production into consideration. This won the HelioTrough the CSP Today innovation award in 2010, and rightly so. In a market where only the most innovative survive, this is a special accolade.

At the moment my colleagues on the Collector Development Team are working on detail improvements under the direction of graduate engineer Jens Kötter. Every additional tenth of a percent of efficiency captures even more sun, thereby increasing the volume of electricity produced and thus the cost-effectiveness of the entire plant. And every component made even marginally less expensive can save millions in construction given the high unit figures. This is how we will make sustainable electricity competitive even more quickly.

An immense motivation for me is the prospect of being able to watch these reflecting giants gently pan from east to west just a few years from now.

As of October 2010