A member of RSC staff (and Chemistry World fan) recently suggested to me that it’s been 100 years since the idea of solar fuels was born. His evidence? A paper by Italian chemist Giacomo Luigi Ciamician published in Science on 27 September 1912. In it, Ciamician proposes how we might harness the enormous power of the Sun to produce fuels from plants:
‘Is it possible or, rather, is it conceivable that…the cultivation of plants may be so regulated as to make them produce abundantly such substances as can become sources of energy…? I believe that this is possible.’
Although he doesn’t use the term, Ciamician is clearly talking about biofuels:
‘…it seems quite possible that the production of organic matter may be largely increased… The harvest, dried by the sun, ought to be converted, in the most economical way, entirely into gaseous fuel…’
And from there he goes on to describe artificial photosynthesis:
‘For our purposes the fundamental problem from the technical point of view is how to fix the solar energy through suitable photochemical reactions. To do this it would be sufficient to be able to imitate the assimilating processes of plants.’
The paper covers the use of sunlight to power the production of all kinds of useful compounds, not just fuels. But it’s this idea of capturing energy from the sun – deliberately and directly – to store in chemical form for later use that is arguably its most compelling. The idea falls within a generalised concept of solar power (or solar energy) but can be demarcated from making electricity directly from sunlight, as photovoltaic solar cells do.
And it’s a hot topic today. Earlier this year, the RSC published a report into solar fuels and artificial photosynthesis describing the rapid rate of progress in this area in recent years.
Indeed, the whole paper seems very prescient. Ciamician highlights a widespread and growing dependence on fossil fuels and questions how industry would cope with a sudden and unexpected price spike.
Perhaps unsurprisingly, he makes a few false steps in his comments about biofuels:
‘There is no danger at all of using for industrial purposes land which should be devoted to raising foodstuffs. An approximate calculation shows that on the Earth there is plenty of land for both purposes, especially when the various cultivations are properly intensified and rationally adapted to the conditions of the soil and the climate.’
But to be fair there were fewer than two billion people on the planet back in 1912. Who could have predicted the impact of a four fold increase over the next 100 years?
In predicting how our rampant thirst for energy would lead us to the Sun, Ciamician seems to be peering into the future with remarkable clarity.