Scots invent hybrid car that cuts fuel use by half

Published on Tuesday 24 February 2009 21:48

SCOTS scientists have invented a car that uses half the fuel of a regular vehicle when driven around a city.

The hybrid car also produces 30 per cent fewer carbon emissions when compared with a standard vehicle.

It was invented by Artemis Intelligent Power, a company formed by researchers from the University of Edinburgh.

They hope it will be on the market in the next three years, helping to lower the carbon footprint of vehicles on the roads.

The engineers, based in Loanhead, Midlothian, have spent the past two years working out how to make use of technology invented by marine renewables researchers at the university to generate electricity from wave energy.

They converted a petrol-driven BMW 530 saloon to use a hydraulic system. They say their creation has a similar performance to a standard BMW, with the same top speed and acceleration. It is driven like an automatic, with no clutch, but otherwise, the driver would notice little difference to a standard car, they claim.

Dr Win Rampen, director of Artemis, who led the project, said when they tested it against a standard BMW they were delighted with the results.

"I think it's an impressive achievement, and we are very proud," he said.

Artemis converted the BMW using a computer-operated hydraulic drive system.

Hydraulic systems, which are normally used in large vehicles such as tractors, traditionally give high levels of control but are also very fuel inefficient.

However, the scientists got past this problem using technology they called Digital Displacement. When the car brakes, the system captures and stores energy that would normally be lost. This stored energy is then used when the car next accelerates.

The car runs on a mixture of stored energy and petrol, switching between the two without the driver having to do anything. It can also run on diesel or biofuel.

Computer control ensures the engine operates at its most efficient speed at all times, using a minimum of fuel.

As a result, the car has the flexibility, power and strength associated with traditional hydraulic technology, but is far more fuel efficient, according to the team.

Artemis has licensed the technology to commercial company Bosch-Rexroth, which has said it aims for vehicles that use the technology to be on the market by 2012.

Dr Rampen said it would be far less expensive than electric hybrids, which he said would be its main competition.

"Our technology represents a serious step forward in terms of cost-effective fuel-economy improvement," he said.

"The system will be much less expensive than electric hybrids, and will help to make hybrid vehicles an economic rather than a lifestyle choice."

Although the system has been built into a BMW 5 Series car, Dr Rampen thinks the best application could be in large vehicles, such as refuse lorries, buses and delivery vans.

"Most people use cars for a very short period of time every day and they use much less fuel than commercial vehicles," he said. "If we can make a big impact in commercial vehicles, we can save more fuel faster."

The company recently won the Rushlight Powered Transport Award, which recognises Artemis as a leading contributor to clean technology development in the UK and Ireland.

The project was supported by the Department for Transport and the Energy Saving Trust.