Last week we covered the development of inflatable wind turbine technology – now it’s solar’s turn.
Heliotube is an inflatable tubular solar concentrator consisting of two chambers. A small difference in pressure between the upper and lower chamber causes the reflective film in the upper tube to curve downwards, forming a trough.
Light travels through the Heliotube’s transparent skin and then reflects off the downward curved mirror film, concentrating the sunlight in the upper chamber on a thermal absorber receiver. Bouncing sunlight in this way focuses the solar radiation by a factor of up to 50 .
The focused sunlight is converted by the thermal absorbers into heat used to create steam, which can be piped to a turbine to generate electricity. Special high performance solar cells could also replace the thermal absorbers to convert concentrated light directly into electricity.
A lightweight solar concentrator system, one square meter of HELIOtube mirror surface weighs just 5 kilogram – far less than up to 130 kilograms of materials used for other constructions according to the company behind the system, Heliovis. The heliotube system is expected to cost just over a quarter of the price of standard parabolic troughs.
Heliovis has already built and operated several prototype concentrators and the company is currently constructing a pilot plant in Dürnrohr, a village in Austria. 40 metres in length with a 1.6 metre aperture, the inflatable solar plant will generate temperatures of up to 320 degrees Celsius and pressures of up to 110 bar.
Heliovis was founded in 2009 by Johannes Höfler and Felix Tiefenbacher. The company has received recognition for its innovation design, including the Viennese Future Prize in 2008 and 2010, the 2009 Golden Daphne Award and the Call Resources award from the Vienna Centre for Innovation and Technology.
Heliovis plans to have a 200-metre long device available on the market by 2016.
