New solar coatings can significantly reduce the need for traditional solar farms
Researchers from the University of Oxford’s Department of Physics have introduced an innovative method of generating solar energy that bypasses the need for conventional silicon-based solar panels. Their new approach involves applying an energy-generating coating to everyday objects ranging from backpacks to vehicles and mobile devices.
This advanced light-absorbing material is not only thin but also flexible, allowing it to adapt to almost any surface, including buildings. By using a technique developed in Oxford, in which multiple light-absorbing plates are placed in a single solar cell, the material captures a broader spectrum of light, resulting in a higher energy yield from the same amount of sunlight.
For the first time, this ultra-thin material with a multi-connection configuration has been independently verified to achieve an energy efficiency of more than 27%. This performance is comparable to that of traditional silicon photovoltaics, which have dominated the market. The certification was granted by Japan’s National Institute of Advanced Industrial Science and Technology (AIST) ahead of the publication of the team’s scientific study later this year.
“In just five years of experimenting with our stacked or multi-junction approach, we have increased energy conversion efficiency from around 6% to over 27%, close to the limits of what single-layer solar photovoltaics can achieve today “, explains Dr. Shuaifeng Hu out. Postdoctoral Fellow in Physics at the University of Oxford. “We believe that this approach could enable photovoltaic devices to achieve much greater efficiency over time, in excess of 45%.”
Current commercial solar panels typically achieve an efficiency of about 22%, but the flexibility and thinness of the new material are significant advantages. With a thickness of just over one micron (nearly 150 times thinner than a silicon wafer), this material can be applied to surfaces beyond traditional solar panels.
“By using new materials that can be coated, we have shown that we can replicate silicon and perform better, while also gaining flexibility. This is important because it promises more solar energy without the need for so much on silicon based panels or purpose-built solar farms,” said Dr. Junke Wang, Marie Sklodowska Curie Actions Postdoc Fellow at Oxford University Physics.
The team expects their technique to reduce the cost of solar energy and further cement solar energy as the most sustainable form of renewable energy. Since 2010, the average global cost of solar energy has fallen by almost 90%, making solar energy significantly cheaper than fossil fuels. This new material, specifically thin-film perovskite, is expected to further reduce dependence on silicon panels and large-scale solar farms.
“We can imagine perovskite coatings being applied to wider types of surfaces to generate cheap solar energy, such as the roofs of cars and buildings and even the backs of mobile phones. If more solar energy can be generated in this way, we can expect less. In the longer term, we will have to use silicon panels or build more and more solar parks,” said Dr. Cheek.
The research team, made up of 40 scientists, is led by Professor of Renewable Energy Henry Snaith at the University of Oxford’s Department of Physics. Their pioneering efforts in solar photovoltaics, especially with thin-film perovskite, began about a decade ago and are supported by a custom-built robotic laboratory.
Their work is commercially promising and is already being integrated into sectors such as utilities, construction and automotive.
Oxford PV, a UK-based company spun out of the University of Oxford’s Physics Department in 2010 by co-founder and Chief Scientific Officer Professor Henry Snaith, has begun large-scale production of perovskite photovoltaics in its factory in Brandenburg-an-der-Havel, near Berlin, Germany. This facility is the first in the world to produce ‘perovskite-on-silicon’ tandem solar cells on a large scale.
“We were originally looking at UK locations to begin production, but the government is yet to match the tax and commercial incentives offered in other parts of Europe and the United States,” said Professor Snaith. “Until now, Britain has thought about solar energy exclusively in terms of building new solar farms, but the real growth will come from commercializing innovations – we very much hope that the newly created British Energy will turn its attention to this .”
“The latest innovations in solar energy materials and techniques demonstrated in our laboratories could become a platform for a new industry, producing materials to generate solar energy more sustainably and cheaply by using existing buildings, vehicles and objects,” Professor Snaith added.
“Supplying these materials will be a fast-growing new industry in the global green economy and we have shown that Britain is innovating and leading the sciences. However, without new incentives and a better pathway to translate this innovation into production, Britain will miss the opportunity to lead this new global industry,” concluded Professor Snaith.
