Materials that heal themselves at a nano scale could revolutionise solar energy, according to a leading scientist.
Speaking at construction innovation event Vision London this week, University College London engineer and material scientist Mark Miodownik said the traditional route of putting solar panels on buildings had big disadvantages.
“They’re not very efficient; if they go wrong then there’s quite a lot of effort to take them out and then plug then back in again; they don’t track the sun; they’re passive; and they have to be manually plugged into the system,” he said.
Miodownik said that self-healing rather than modular systems would be needed for the sun’s energy to be harvested on an industrial scale. Fields of solar panels would need to look after themselves to prevent the upkeep costs outweighing the benefits, he said. Clever things to increase efficiency - such as optical wave guides, done at a nano scale - could recover some of the light which may otherwise be lost.
“Down at the nano scale, there is a whole new category of light harvesting materials,” said Miodownik. “Perovskites - they’re very cheap; they can be made roll to roll; they have efficiencies approaching 15% to 20% in the lab already; and they’re much cheaper than the silicon alternatives because they don’t need clean room facilities.
“Designing things at the nano scale and then designing into them ways of looking after themselves - so healing themselves when they have a short circuit or get dust occluding them - that’s going to be a very big direction of travel.”
The scientist also enthused on the subject of carbon fibre, saying new airplanes were now up to 70% carbon fibre, but that the processes of making carbon fibre into complex shapes was still really basic.
Electric cars would only reach comparable performance levels to traditional vehicles if the production of carbon fibre became automated, he said.
Miodownik added that carbon fibre used in manufacturing was currently made from mats filled with amorphous carbon.
“That means that the carbon in this form is about 100 times less strong than it could be if those fibres were made exclusively of things like carbon nano tubes or rolled up graphene,” he said.
“The government has just invested £30M in a graphene centre in Manchester. People are working from the ground upwards to make this stuff on an industrial scale. In five to 10 years’ time, you could have a spoke of a wheel made of this which is invisible to see, has enough strength and stiffness to hold the wheel and you up but is much smaller than a hair. If you think of the design possibilities of that material it’s pretty exciting.”