We can make existing solar technology more efficient and accessible, said renewable energy professor.
In this week’s Net Hero Podcast, Professor of Physics at the University of Oxford, Prof. Henry Snaith said: ‘You can never get a 100 per cent efficiency with the type of solar panels we have today.
‘Looking at the laws of physics and how we understand this process of converting sunlight to electricity, the maximum efficiency for a single material like silicon would be about 30 to 31 per cent efficiency. And that would be the maximum efficiency. The panels we currently have are around 20 to 22 per cent.
‘In terms of the environmental impact, some materials that renewable technologies like solar use are more damaging than others.
‘An example of this is Indium which is a transparent conducting film used in some solar technologies. Its a material that is quite costly to mine and has a big environmental impact. So there has been a lot of work done to find substitutions for Indium. People are also trying to use less silicon in photovoltaics.
‘Perovskites are a metal halide that we found works really well as a solar energy absorber and a solar cell material.
‘And we’ve worked out how to make really efficient solar cells with this material. It is something that not just competes with silicon, which is what we’re using today but it performs better and more efficiently than solar.
‘In terms of the absorption of light, the perovskite materials need about a hundredth of the thickness of silicon to absorb the same amount of light. So they’re much thinner.’
Prof. Snaith told us that contrary to popular belief, the technology he developed could easily work in countries such as the UK that don’t get as much sunlight.
He said: ‘It’s true that we don’t get much sun in the UK but we can get 120 watts per square meter as a daily average. So imagine your 100 watt light bulb. So on a 24 hours a day, 365 days a year, you can get enough power to power a light bulb.
‘Of course somewhere sunnier like North Africa can generate more electricity from the sun, about 250 watts, so two and a half light bulbs.
‘But we can definitely produce all the electricity we need in the UK from the sun even if we only cover 1 per cent of land with solar panels. But if we covered all our buildings with solar at only 20 per cent efficiency, we would be able to all the electricity we need.
‘The issue is industrial buildings, warehouses and supermarkets, buildings that take up a large amount of space but don’t as of yet use solar panels. These buildings could offset a large fraction of their power demand if they used solar panels but often these roofs are not strong enough to hold traditional panels and this is where lightweight panels could work really well.’
Henry said that the UK government must incentivise renewable businesses to set up in the UK.
He said: ‘Solar energy is needed everywhere and there are tons of companies globally that are building up manufacturing capacity with these materials. A lot of it is China, so there is going to be a lot of competition.
‘The government needs to put a package together that makes UK the most economically sensible place to build renewable, specifically photovoltaic, technologies.
‘This could be one of advantages of having left the European Union. We could set our own rules. But they need to focus, look at what other countries are doing and we need to do better than what they are doing.’
‘There is no reason that this cannot be scaled up in the UK but it has to be competitive. The right incentives in the form of tax breaks, reliefs and the availability of inexpensive capital to build the factories need to be put in place.
Watch the full episode below and don’t forget to check out the 100 Days of Labour online event next week.
Watch the full episode below and don’t forget to check out the 100 Days of Labour online event next week.
