Nanotech key in weaning Europe off oil

Optimistic views of global solar power are possible say ESF

On 140 acres of unused land on Nellis Air Force Base in the US, 70,000 solar panels are part of a solar photovoltaic array that will generate 15 megawatts of solar power for the base

That is the message coming out of a conference held by the European Science Foundation - an optimistic scenario they admit, but one that they say is coming closer to reality as new technologies such as biomimetics and Dye Sensitised solar Cells (DSCs) emerge with great promise for capturing solar energy.

“The potential of solar power is much, much larger in absolute numbers than that of wind,” said Professor Bengt Kasemo from Chalmers University of Technology and the chair of the ESF conference. However, like wind, the potential of solar power generation varies greatly across time and geography, being confined to the daytime and less suitable for regions in higher latitudes, such as Scandinavia and Siberia. For this reason there is growing interest in the idea of a global electricity grid according to Kasemo.

“If solar energy is harvested where it is most abundant, and distributed on a global net it will be enough to replace a large fraction of today's fossil-based electricity generation,” said Kasemo. “It also would solve the day/night problem and therefore reduce storage needs because the sun always shines somewhere.”

In the immediate future, solid state technologies based on silicon are likely to predominate the production of solar cells, but DSC is likely to lower costs in the long term, using cheaper semiconductor materials to produce robust flexible sheets strong enough to resist buffeting from hail for example. Although less efficient than the very best silicon or thin film cells using current technology, their better price/performance has led the European Union to predict that DSCs will be a significant contributor to renewable energy production in Europe by 2020.

Some of the most exciting alternatives, heard the Nanotechnology for Sustainable Energy conference, lie in the field of biomimetics - mimicking processes that have been perfected in biological organisms. Photosynthesis, for example, can potentially be harnessed either in genetically-engineered organisms - or completely artificial human-made systems that mimic the processes - to produce carbon-free fuels such as hydrogen.

Commercial realisation of biomimetic and other emerging technologies lies far in the future, however the key point to emerge from the ESF conference is that there will be growing choice and competition between emerging nanotechnology-based solar conversion technologies. “I think the important fact is that there is strong competition and that installed solar power is growing very rapidly, albeit from a small base,” said Kasemo. “This will push prices down and make solar electricity more and more competitive.”