Instead of silicon-based solar panels, the new innovation discovered by Oxford University scientists works by coating a new power-generating material onto the surfaces of everyday objects “like rucksacks, cars and mobile phones”. For the first time, the newly discovered light-absorbing material is thin and flexible enough to apply to the surface of almost any building or common object.
Using a pioneering technique developed in Oxford, which stacks multiple light-absorbing layers into one solar cell, they have managed to harness a wider range of the light spectrum, allowing more power to be generated from the same amount of sunlight. This ‘multi-junction approach’ has now been independently certified to deliver over 27% energy efficiency, matching the performance of traditional, single-layer, energy-generating materials known as silicon photovoltaics.
The researchers believe their new revolutionary approach will not only reduce the cost of solar, but also make it the most sustainable form of renewable energy. Since 2010, the global average cost of solar electricity has fallen by almost 90%, making it almost a third cheaper than that generated from fossil fuels. In addition to the cost savings, important innovations such as these reduce the need for silicon panels and purpose-built solar farms. Considering too, that the supply of solar panels for the EU market is highly dependent on imports, with more than 97% of the solar panels deployed in Europe being imported, mainly from China.
“During just five years experimenting with our stacking or multi-junction approach we have raised power conversion efficiency from around 6% to over 27%, close to the limits of what single-layer photovoltaics can achieve today,” said Dr Shuaifeng Hu, Post Doctoral Fellow at Oxford University Physics. “We believe that, over time, this approach could enable the photovoltaic devices to achieve far greater efficiencies, exceeding 45%.”
This compares with around 22% energy efficiency from solar panels today, but the versatility of the new ultra-thin and flexible material is also key. At just over one micron thick, it is almost 150 times thinner than a silicon wafer and unlike existing photovoltaics this can be applied to almost any surface.
“By using new materials which can be applied as a coating, we’ve shown we can replicate and out-perform silicon whilst also gaining flexibility. This is important because it promises more solar power without the need for silicon-based panels or specially-built solar farms,” said Dr Junke Wang, Marie Skłodowska Curie Actions Postdoc Fellow at Oxford University Physics.
The researchers are among 40 scientists working on photovoltaics led by Professor of Renewable Energy, Henry Snaith at Oxford University Physics Department. Their pioneering work in photovoltaics and especially the use of thin-film perovskite began around a decade ago and benefits from a bespoke, robotic laboratory. With strong commercial potential of the new innovation, work has already started into applications across the utilities, construction and car manufacturing industries. Oxford PV, a UK company spun out of Oxford University Physics recently started large-scale manufacturing of perovskite photovoltaics at its factory in Brandenburg-an-der-Havel in Germany.
“We originally looked at UK sites to start manufacturing but the government has yet to match the fiscal and commercial incentives on offer in other parts of Europe and the United States. Thus far the UK has thought about solar energy purely in terms of building new solar farms, but the real growth will come from commercialising innovations – we very much hope that the newly-created British Energy will direct its attention to this,” explained Professor Snaith.