As rising energy prices squeeze family budgets and consumers begin to see using less water and electricity as easy on the pocket as well as on the environment, a new generation of environmentally conscious engineers is changing the way people think about

Seventy per cent of energy can go towards heating the water in one of the home's most energy-hungry appliances. Experiments have shown that in many cases cold water does the job just fine – it's been found that cold water is actually better at removing protein-based stains, and works better with bleach.

One of the more interesting ideas to emerge is the idea of replacing water with solid solvents. A Leeds University professor is already working on plans for such a machine. A cup of water and detergent suffices to loosen stains, and then the clothes are spun in a storm of dirt-absorbing plastic chips. The technology could be available to consumers as early as 2009.

Some revolutionary ideas have already hit the market. Sanyo sells a washing machine in Japan that 'shakes' dirt from clothes by blasting them with ultrasound rays. The company claims it halves the cost of washing laundry.