Evert Raaijen, technical director of energy conversion company Exendis, felt the technology could have a number of different applications.

CNN: Are we heading for a human-powered future?

The big challenges are the high cost of a conversion plant and their technical complexity.

FORBES: Energy Forecast 2013-2014: Convert to Natural Gas

Because under the terms of its government bailout, RBS has the right to sell new shares to the government at 50p per share, or roughly twice the current price (in technical terms, 50p is the conversion price of RBS's 'B' shares).

BBC: If RBS needs capital, taxpayers will suffer