One alternative is a cable that uses a combination of aluminium and carbon-glass fibre composite.

ECONOMIST: ENERGY: Building the energy internet | The

Part of the investment will be used to install high-volume composite carbon fibre manufacturing equipment.

BBC: Penso engineering firm plans 'to create 100 jobs'

So far, the company has built a one-eighth-size prototype to test its design, which consists of a carbon-fibre keel, an envelope made from modern composite materials, half-a-dozen engines, a passenger compartment, and a specially lightened crane.

ECONOMIST: Pushing the envelope

Worldwide, airlines have been slowly but steadily putting into operation two next-generation aircraft -- Boeing's 787 Dreamliner and the Airbus A350 -- both of which have shells made heavily of composite materials, such as carbon-fibre reinforced plastic, instead of aluminium.

BBC: Increased comfort in the sky

One of the ways that Chapman added lightness to his cars, the use of composite materials such as carbon fibre and glass-reinforced plastic, is not that practical either.

ECONOMIST: Tech.view: Unbearable lightness? | The