Letter: Better ways of making use of carbon dioxide (2)

From Patrick Walker, Edinburgh, UK

In discussing ways to turn carbon dioxide into useful products, Marshall highlights that the energy costs of splitting hydrogen from water and carbon from CO₂ may make “carbon emission free” petrol too expensive.

Is this a post-oil opportunity for countries like Saudi Arabia? They have plenty of sun to generate solar energy. Desalinated seawater could provide the H₂O. The sunlight conversion efficiency might be low, but the sunlight itself would be free. The resulting liquid fuels would be compatible with existing infrastructure in such oil-producing countries.