The Sustainable Global Energy Economy: Hydrogen or Silicon?

A sustainable global silicon energy economy is proposed as a potential alternative to the hydrogen economy. This first visualisation of a silicon energy economy is based on largescale and carbon-neutral metallic silicon production from major smelters in North Africa and elsewhere, supplied by desert silica sand and electricity from extensive solar generating systems. The resulting “fuel silicon” is shipped around the world to emissionfree silicon power stations for either immediate electricity generation or stockpiling. The high energy density of silicon and its stable storage make it an ideal material for maintaining national economic functioning through security of base load power supply from a renewable source. This contrasts with the present situation of fossil fuel usage with its associated global warming and geopolitical supply uncertainties. Critical technological requirements for the silicon economy are carbon-neutral silicon production and the development of efficient silicon-fired power stations capable of high-temperature rapid oxidation of fuel silicon. A call is made for the development of research effort into these specific engineering issues, and also with respect to large-scale economical solar power generation.