Some proposed technological innovations seem so far out that they are easy to reject out of hand. But sometimes, a new idea has a kernel of plausibility. Such is the case with a new project to develop a laser power generation system that its creator says could provide electricity for the grid, stand-alone power applications and even cars.

Laser Power Systems (LPS) from Connecticut, U.S.A, is developing a new method of automotive propulsion with one of the most dense materials known in nature - thorium.

Thorium, a silvery-white metal, is a mildly radioactive element that is as abundant as lead. It is present in large quantities in India and is a much-touted stand in for uranium in nuclear reactors because its fission is not self-sustaining, a type of reaction called 'sub-critical'. Because thorium is so dense, it has the potential to produce tremendous amounts of heat. The company has been experimenting with small bits of thorium, creating a laser that heats water, produces steam and powers a mini turbine.

Current models of the engine weigh 500 pounds, easily fitting into the engine area of a conventionally-designed vehicle. According to CEO Charles Stevens, just one gram of the substance yields more energy than 7,396 gallons (28,000 litres) of petrol and eight grams would power the typical car for a century.

LPS is developing the technology so it can be mass-produced but whether authorities will allow thorium-powered cars to roam the streets is another question and a date has not been for a prototype version yet.