Solar concentrator makes use of telescope mirrors

The University of Arizona’s tracker prototype supports two curved, highly reflective glass mirrors, each measuring 10ft by 10ft.

‘Most mirrors used in solar power plants are used for thermal generation by focusing light onto a long pipe used to heat water into steam,’ team lead Prof Roger Angel said. ‘This requires the mirrors to be shaped like a cylinder. What we have learned here at the Mirror Lab is how to bend the glass to high accuracy so as to focus to a point or a line.’

The US Department of Energy recently granted $1.5m (£964,000) to Angel’s research group to extend the mirror-making process to the so-called thermal method for making solar electricity. The mirror-making process will be optimised for cost-efficient mass production. The group has already patented its method for making dish-shaped glass mirrors.

The mirrors focus sunlight onto a 5in glass ball and from there to a small array of 36 highly efficient photovoltaic (PV) cells, developed originally to power spacecraft. They convert a broader range of the solar spectrum into electricity than regular cells.