Tower of power

Hamilton Sundstrand and the US Renewables Group are to commercialise a concentrated solar power tower technology and corresponding molten salt storage system developed by United Technologies' Rocketdyne division through a new company known as SolarReserve.

The power tower system itself uses a large field of mirrors to concentrate sunlight onto the top of a tower, where a receiver sits. This heats molten salt flowing through the receiver. Then, the salt's heat is used to generate electricity through a conventional steam generator.

Molten salt retains heat efficiently, so it can be stored for days before being converted into electricity. That means electricity can be produced on cloudy days or even several hours after sunset.

'Due to the unique ability of the product to store the energy it captures, this system will function like a conventional hydroelectric power plant, but with several advantages. We will have the capability to store the sun's energy and release it on demand. This product is more predictable than water reserves, the supply is free and inexhaustible, and the environmental impact is essentially zero,' said Lee Bailey, managing director of the US Renewables Group.