CNN
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A coating 100 times thinner than a human hair could be “inkjetted” onto your backpack, cellphone or car roof to harness the sun’s energy, new research shows. A development that could reduce the world’s need for solar farms that take up huge areas of land.
Scientists at the University of Oxford’s Department of Physics have developed a micro-thin, light-absorbing material that is flexible enough to be applied to the surface of almost any building or object – with the potential to up to almost twice the amount of energy of current solar modules.
The technology comes at a crucial time for the solar energy boom, as human-caused climate change is rapidly warming the planet and forcing the world to accelerate the transition to clean energy.
And this is how it works: The solar coating consists of materials called perovskites, which absorb solar energy more efficiently than the silicon-based panels widely used today. This is because their light-absorbing layers can wider spectrum of light from sunlight than conventional panels. And more light means more energy.
The Oxford scientists are not the only ones to have created this type of coating, but theirs is remarkably efficient, capturing about 27% of sunlight’s energy. Today’s solar panels, which use silicon cells, typically hide converts up to 22% of sunlight into electricity.
The researchers believe that perovskites can achieve an efficiency of over 45 percent over time. They point to the increase in yield that they were able to achieve from 6 to 27 percent in just five years of experimentation.
“This is important because it promises more solar power without the need for silicon-based panels or purpose-built solar farms,” said Junke Wang, one of the Oxford scientists. “We can imagine applying perovskite coatings to wider surfaces to generate cheap solar power, such as on the roofs of cars and buildings, and even on the backs of mobile phones.”
At just over a micrometer thick, the coating is 150 times thinner than a silicon layer used in today’s solar panels. And unlike existing silicon panels, the perovskites can be applied to almost any surface, including plastic and paper, using tools such as an inkjet printer.
Globally, solar panel installations have skyrocketed and are expected to grow 80% in 2023 compared to 2022, according to Wood Mackenzie. a company specializing in data and analytics for the energy transition. Solar was the fastest-growing source of electricity in 2023 for the 19th year in a row, according to the “2024 Global Electricity Review” by climate think tank Ember.
A key driver of this boom is the falling cost of solar energy. It is now cheaper to produce than any other form of energy, including fossil fuels. Another important factor driving the rise of solar energy is its increasing efficiency in converting solar energy.
However, ground-based solar parks require a lot of land and are often at the centre of conflicts between the agricultural industry and the governments and companies behind the renewable energy plants.
The Oxford researchers say their technology can solve this problem while also reducing energy costs. Wang noted, however, that the research group is not advocating an end to solar farms.
“I wouldn’t say we want to eliminate solar farms because obviously we need a lot of areas or land to generate a sufficient amount of solar energy,” he told CNN.
However, one persistent problem with perovskites is their stability, which has so far prevented developers from commercializing the technology. Some coatings in the lab have dissolved or degraded within a short period of time and are therefore considered less durable than today’s solar panels. Scientists are working to improve their lifespan.
Henry Snaith, lead researcher of the Oxford team, said their work had great commercial potential and could be used in industries such as construction and automotive.
“The latest innovations in solar materials and techniques that we demonstrate in our labs could become the platform for a new industry that produces materials that can generate solar energy more sustainably and cost-effectively using existing buildings, vehicles and objects,” he said.
Snaith is also director of Oxford PV, a spin-off from the University of Oxford’s Institute of Physics, which recently began mass production of perovskite solar modules at its factory in Germany.
