Advanced Technology Institute

Why the sky’s the limit for solar energy

In an interview with nanotechweb.org, Professor Ravi Silva outlines how research into processed organic materials could enable solar energy systems that cost a thousandth of their current price.

Professor Silva, Head of Surrey’s Advanced Technology Institute (ATI), gave the in-depth interview with leading nanotechnology website nanotechweb.org during the 2nd International Conference on Advanced Energy Materials, which took place at the University of Surrey on 11 to 13 September 2017.

The Earth receives enough energy in an hour to power civilization for a year. However, capitalising on the opportunities offered by solar power requires solar cells that are highly efficient, but cheap to make and install. While first generation silicon-based solar photovoltaic (PV) systems offer one answer, the costs of processing and installing these cells is still too high for them to replace fossil fuels, and subsequent solutions for solar cells have not been able to match the performance or the reliability of first generation systems.

Professor Silva hopes that a fourth generation of solar cells, being developed in the ATI, will achieve the balance of efficiency and cost needed to bring about a solar-power revolution. Using learnings from the previous technologies, he and his colleagues aim to develop composite cells that combine the efficiency benefits of inorganic materials and nanostructures, with the convenience and low cost of ‘solution-processable’ organic polymers.

“Solution-processed materials can have thicknesses a thousandth of that of a typical solar cell – more like paint that can be put on a building,” said Professor Silva. “What we are trying to do is to reduce the cost of the material not just a hundredfold, but a thousandfold. And we can reduce the system costs too: instead of a system producing energy at 20 cents per Watt, say, we are trying to reduce it to 2 cents, so that there can be no financial basis for sticking with the current fossil fuels.”

The goal is to create systems which pay for themselves within six months rather than the 20 years needed for current silicon-based PV.

The ATI is currently focused on scaling up its successful prototype systems through two EU-funded programmes, SMARTONICS and CORNET, in collaboration with a range of academic and industry partners. In order to bring its innovations to market, the ATI is working with companies such as Tata Steel to investigate ways of integrating large scale solar panels into structural materials.

Professor Silva explained: “Presently the biggest problem we have is that steel facias and roofs are bespoke, and solar cells have to be installed separately on top. If they can both be incorporated into a single unit, as found in BIPV, installation is much more economical.”

Another area being explored by the ATI is solution-processed indoor solar PV applications which rely not on sunlight but on energy ‘scavenged’ from the environment.

“There is a lot of energy in the electromagnetic spectrum that is not being used at present simply because we have not chosen to harness it,” said Professor Silva. “In the case of solar PV, the sky is the limit: energy is everywhere, we just need to find efficient means of harnessing it.”

Read the full interview with Professor Silva.

Read more about the ATI’s research in large area organic solar cells.

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