Scientists at Stellenbosch University have found a way to harness cheap solar energy by perfecting a process that has stumped the world's best engineers for years. As news of the ground-breaking design travelled across the globe yesterday, the scientists behind Helio100 continued testing of their prototype.The Solar Thermal Research Group has dramatically reduced the cost of creating heliostats - computer-controlled mirrors that keep the sun reflected on a fixed target as it moves across the sky.Paul Gauche, director of the research group, said his team's aim was to produce concentrated solar power technology that would be cheap and quick to install."Helio100 consists of a field of tracking mirrors and a small tower that captures concentrated sunlight capable of running a turbine at 1000C," said Gauche."Air is heated to drive a gas turbine similar to those in jet engines. This means no water or other working fluids are needed."But the cost of heliostats has' until now made them impractical."We are developing 'plonkable' small-scale heliostats. 'Plonkable' means that you can just drop them on to the ground and they work," he said.The design requires no costly building work or a highly trained workforce for installation, only two people to lay out the steel frames on the ground and a streetlight-style central tower.A Helio100 installation consists of 100 2.2m² heliostats generating 100kW of power in total - enough to power about 30 households.The pilot installation is in Mariendahl, an experimental farm between Stellenbosch and Klapmuts.Helio100 spokesman Sebastian Bode said the Stellenbosch team's work had attracted the interest of companies including a German consortium, and a Massachusetts Institute of Technology solar energy company.Engineers on Google's Renewable Energy Cheaper than Coal project attempted to build something similar but abandoned their research in 2011 when they could not do it cheaply enough.Bode said the use of a Helio100 array was cheaper than using diesel, the usual fuel for most companies and businesses during power outages.The SA Photovoltaic Industry Association's Wido Schnabel hailed the announcement as "brilliant news"."The beauty of concentrated solar power technology is that it allows us to store much more energy than photovoltaic panels. This means we have energy for cloudy days or at night," he said."It also means that we can add concentrated solar power technology to the symphony of renewable energy solutions we currently have, and gives us another incentive to stay away from nuclear power generation and burning coal."..