The evolution of plant photosynthesis was a defining moment in the early history of life on Earth. By converting sunlight into stored forms of energy, plants enabled life to evolve into the wondrous complexity of living organisms we recognise today.
We are now of course burning through one of these photosynthetic energy stores – the fossil fuels buried underground for millions of years – with potentially disastrous consequences for the environment. This is why we need safe, renewable alternatives to coal, oil and gas.
Solar power is one such renewable energy source. Like photosynthesis, it relies on capturing and converting sunlight into another form of power – electricity in the case of the photovoltaic (PV) cells of solar panels.
The trouble with solar, as many homeowners with solar panels on their roof will explain, is that it is costly. It can take between 10 and 15 years to recoup the costs of the panels, even with generous government subsidies and feed-in tariffs.
However, the march of technological progress is making PV cells cheaper and cheaper. Forty years ago, when solar panels first came on to the market, the cost of generating a watt of PV electricity was about $70, at 2012 prices, whereas it is less than a dollar today. The next generation of PV cells, based on cadmium telluride instead of silicon, will be made even cheaper by the kind of technological advances announced by scientists at Liverpool University, who have replaced a toxic and expensive component of cadmium cells with one based on an edible sea-salt.
Before the credit crunch of 2008, solar power was seen as the most exciting of the renewables. But this was helped by generous EU and government subsidies that have since dwindled to a trickle. Now, we are on the cusp of a new renaissance in solar power, this time driven by hard economics rather than subsidies. The scientists behind this latest advance therefore deserve the applause and support of everyone interested in a cleaner, greener future – not just in Britain, but far beyond.