Barnham is a leading researcher and developer of silicon solar cells and, for a while, his team held the world record for the most efficient version of this rapidly improving technology. He is not an ivory-tower scientist and has worked to commercialise his discoveries – but he has come up against the chronic failure of British industry and finance to nurture such innovative technology.
He has a conceit to make the point about solar versus fossil and nuclear fuels. Imagine there really are more advanced civilisations in the universe than ours: the reason we've never heard from them is that they've taken one look at earth, where we are still burning fossil fuels and uranium instead of using solar power, and decided that "earthlings are too stupid to be worth colonising".
Propagandists for fossil fuels and nuclear power have tried to discredit renewable energy with lazy, superficially plausible objections: in a country like Britain there's not sufficient sun, the wind doesn't always blow, and so on. But, as with all science, common sense is a poor guide. Barnham demonstrates that even in northern countries there is quite enough renewable energy available. Indeed, the Scandinavian countries plus Germany are the leaders in renewables, with Iceland (geothermal) and Norway (hydroelectric) close to 100% in renewable electricity generation. If they can do it, so can Britain.
Barnham proposes a combination of technologies. As a leading photovoltaic solar cell inventor, he gives this pride of place, along with onshore wind, biogas from waste food and underground heat pumps. The last two are the least familiar but perhaps most promising for filling the gaps when the sun doesn't shine and the wind doesn't blow. In Sweden more than 90% of new homes have ground source heat pumps installed: just two metres down the ground retains sufficient warmth to provide hot water for a house via reverse refrigeration technology. Biogas technology puts to use the methane from household waste. Instead of adding to global warming by dumping waste in landfill (methane is 25 times more potent a greenhouse gas than CO2) it can be used either to supplement natural gas to generate electricity or for domestic heating and cooking.
Perhaps the most important of all Barnham's correctives to the received wisdom on energy sources is his stress on developing biofuels from the very CO2 that is tipping the world's climate into the danger zone. Carbon dioxide is the source of all living plant material (biomass) and fossil fuels. The best-known technology for reducing CO2 emissions at source is carbon capture and storage, but why pay to bury it when it could be put to use? To do this we have to learn what every leaf knows: how to turn sunlight, CO2 and water into biomass.
The race to mimic nature's two photosystems is the greatest scientific challenge of our time, the Manhattan Project and the Moonshot rolled into one: far more important in fact but not necessarily more expensive or more demanding of resources or ingenuity. Unravelling nature's mechanism is almost complete – an achievement arguably as great as DNA sequencing but, astonishingly, so far unknown to almost everyone. One of the pioneers is Barnham's colleague at Imperial College, James Barber.
theguardian