Solar Energy Perspectives - IEA

Chapter 9: Solar fuels
Chapter 9
Solar fuels
Solar energy can be used to generate hydrogen from water electrolysis or various processes
based on water or any hydrocarbon, and concentrated solar heat. Hydrogen can be used as
such or to further process other fuels, notably convenient liquid fuels. For liquid fuels, which
normally contain carbon atoms, the preferred option from a climate point of view is solarenhanced
bio-fuels.
Background
In 1904, Manuel Gomez, a Portuguese Jesuit nicknamed Padre Himalaya, aiming at
synthesising fertilisers, obtained a temperature of 3 800°C from concentrating sunrays in his
‘Pyreheliophoro’ (Photo 9.1).
In the last 20 years, scientists in Europe, Israel, Japan and the United States have been working
on gaseous, liquid or solid “solar fuels” manufactured from carbonaceous feedstock or water.
In 2011, in his State of Union speech, President Obama alluded to solar fuels: “At the
California Institute of Technology, they're developing a way to turn sunlight and water into
fuel for our cars.”
Photo 9.1 Padre Himalaya’s Pyreheliophoro in 1904
Source: Collares Pereira.
Key point
Solar fuels were first considered more than a century ago.
161
© OECD/IEA, 2011