A “zero-emission” sports car launched at the Geneva Motor Show.

The hydrogen-powered Lifecar, based on the design of the Morgan Aero-8 roadster, produces little noise and only water vapour from its exhaust.

The lightweight model packs advanced fuel cells and an energy storage system that gives the car a range of 250 miles (400km) per tank of hydrogen.

It has been developed by a consortium of UK companies and universities.

“Figures suggest the car should be capable of doing 0-60 [miles per hour] in about seven seconds,” Matthew Parkin of classic sports car manufacturer Morgan told BBC News.

However, the exact acceleration will not be known until the complete car is taken for its first test drive.

“It’s nearly there and the plan is to drive it when the show is over,” said Mr Parkin.

Clever power

The £1.9m project to build the Lifecar, part funded by the UK government, has taken nearly three years. “The basic concept was to build an entertaining and fun sports car that would act as a showcase for the technology and would deliver 150 miles to the gallon,” said Mr Parkin.

“Everything else has tumbled out from that.”

The car is powered by a bank of lightweight hydrogen fuel-cells developed by UK defence firm Qinetiq.

“If you took a typical internal combustion engine and replaced it with a fuel cell, the fuel cell would be very large,” explained Ian Whiting of Qinetiq. “That’s not an efficient way to do things.”

The fuel cells in the Lifecar produce about 22 kilowatts - roughly one fifth of the amount of power of a typical combustion engine.

“With that we can provide all of the cruise capability we need to,” he said.

When the car needs to accelerate or climb a hill it draws extra power from a bank of ultra-capacitors aligned down the centre of the car. “They are like a battery but they do not store quite as much energy and they allow the energy in and out much quicker,” explained Mr Whiting.

These are primarily charged by a regenerative braking system which slows the car by converting the vehicle’s kinetic energy into useful electrical energy using a motor.

“Hybrid cars already use regenerative braking - normally it restores about 10% of the energy,” said Mr Parkin. “Lifecar is aiming for 50%.”