A quiet solar revolution is underway, powered by thin-film solar technology. This groundbreaking innovation provides a flexible, lightweight and versatile alternative to traditional silicon-based solar panels, and promises to reshape how and where we harness energy from the sun.
Thin-film solar cells can be integrated into unexpected surfaces, such as building facades, windows or the growing floating solar market. The flexibility of thin film opens doors to new applications and helps overcome some of the barriers that have long limited solar energy adoption.
Much of the interest in thin-film solar energy technologies comes from one company based in the heart of Britain: Power Roll. The County Durham-based company has spent years exploring how to make thin, flexible solar cells that can be used virtually anywhere and has recently achieved major milestones in commercializing the technology in a bid to spread it around the world.
Solar energy portal spoke to Power Roll CEO Neil Spann to explore how thin-film solar could deliver the government’s promised ‘roof revolution’ and how Power Roll’s unique manufacturing process can make solar energy a low-cost reality worldwide.
What is thin-film solar energy?
Essentially, Spann explains, Power Roll’s thin-film solar technology rotates the solar cell arrangement 90 degrees from the standard arrangement of layers of chemicals and materials with contacts on opposite sides. Power Roll’s cells are absolutely minuscule; each cell is about one micrometer wide – about one-fiftieth the width of a human hair – and many cells are connected by individual contacts.
In a 100cm2 sample of the material, 55,000 individual solar cells are crammed into micro-grooves, which are vacuum-coated on either side using a process adapted from methods used in food packaging production. This provides the highest resolution conductive surface currently available, and the thinness of the material allows it to be manufactured using a roll-to-roll process common in many industries and thus at significantly lower costs than much traditional solar energy. energy production.
Perovskites and thin films
This manufacturing process meets another material currently making waves in the solar industry: perovskites. Perovskites are perhaps the most important development the solar industry has seen in recent years, due to their incredibly light weight and tremendous efficiency. A team of scientists from the University of Oxford recently demonstrated a conversion efficiency in perovskite materials of up to 27%. %. The research team believes that conversion efficiency could well exceed 45% in the future, far higher than much of the technology currently on the market.
The advantages of perovskites go well beyond their efficiency and low weight: the materials used in these types of films do not require rare earth elements, unlike other solar technologies, which is enormously beneficial both in terms of financial costs and in terms of human costs. sourcing such materials, which have been linked to human rights violations in the past.
Spann notes: “We do not use rare earth elements, and all the materials we use are abundant on Earth and can be mined worldwide. So we’re trying to break the dependency on some of those very rare earths, and also those that have very limited supply chains to one particular location or one particular supplier.”
Spann wants to emphasize that perovskites are not the only or even the most important part of Power Roll’s unique technology. It is the combination of the perovskite material and micro-groove production that is what makes Power Roll so effective.
He adds: ‘We happen to use perovskites as a solar absorber, but we are not a perovskite company. It is the material in which we applied it. We have proven that our microgroove technology works with several other solar absorbers.”
The thin film advantage
Spann points out that one in three buildings in Britain are unable to support the weight of traditional roof-mounted solar panels, a fact that is not surprising given Britain’s aging building stock.
Commercial industrial roofs in particular are a “very exciting” application, according to Spann, as many industrial facilities, including Power Roll’s, are unable to support the weight of silicon panels but have enormous power needs – a clear use case for the technology.
Furthermore, in what Spann calls a “somewhat left-field” application for the technology, floating solar power – which we explored in a previous study Solar energy portal blog post – is an extremely useful use case for the technology, with the flexible nature of the film playing extremely well with the ever-changing nature of ocean waves.
There is another area that Spann is personally passionate about as a use case for the technology: off-the-grid applications. With more than 600 million people around the world having no access to electricity at all, let alone green electricity, the opportunity to bring cost-effective, lightweight technology to the farthest corners of the world is something Spann calls “huge and exciting.” , because you really make a difference”.
He adds: “If there’s a surface, there’s potential there.”
Thin-film solar energy: the commercial future
Any new technology will eventually raise the difficult issue of commercialization, and this, Spann says, is where the company will focus much of its efforts over the next five years and beyond. The company recently received a £4.3 million funding injection from the Northern Powerhouse Investment Fund II (NPIF II), and last month the company partnered with packaging manufacturer Amcor to expand Power Roll’s processes in the UK.
Power Roll is currently developing a gigafactory to produce the technology at scale and plans to locate the factory in County Durham to bring the next steps in the green revolution to the area. Once completed, this plant will be the first gigawatt-scale solar plant in the UK.
Spann notes that the company has just appointed a new COO, joining from electronics giant Hitachi, and adds that continued capital is the final piece of the puzzle. He says: “We have the plans, we have proven production. We now need the capital to deploy that, and we hope to close that round within a few months.”
In addition to this first gigafactory, world domination comes in the form of licensing production facilities around the world.
“Our international plan is to license and collaborate globally, so we have already engaged a number of potential commercial licensing partners early on. So the UK factory acts as a blueprint from which we can set up a factory in India, we can set up a factory in Japan, we can set up a factory in the US or Europe.
“So it is very important to really scale up solar film significantly within a five-year horizon in Great Britain, but also to scale up globally with international partners.”