A developer of solar thermal technology has completed the building of a 540 foot tower in Nevada, taking it one step closer to providing power from the sun, at night time. US company SolarReserve is building a system which works by heating molten salt, which can then be stored for up to 15 hours before being used to generate electricity on demand.
The tower will have sun light from over 10,000 mirrors directed towards it where a receiver full of the molten salt absorbs the multiple rays and heats up. The fluid is able to remain in a liquid state at temperatures of 1000°C, which allows it to be stored and used at a later stage.
Kevin Smith,CEOof SolarReserve said the technology provides a truly alternative source of power: “Our technology has the ability to store energy for 10-15 hours and solves the issue of intermittent power generation to the grid, the number one limitation to other solar and wind renewable energy technologies. We can deliver electricity ‘on demand’ the same way a coal, natural gas or nuclear fueled plant does – but without emitting any harmful pollution or hazardous materials – providing a genuine alternative to conventional power generation.”
The stored heat is used to create steam which drives a turbine to create electricity. The steam is then condensed back to water and returned to the tank, where it will flow back into the steam generator when needed. After the molten salt passes though the steam generator, it flows back to the cold tank and is re-used throughout the life of the project.
The 110MW project will supply power to 75,000 homes and is expected to be completed in 2013.