#MakeSolarEU: Oxford PV's role in reshoring solar manufacturing to Europe

The company is a 2010 spin-out from Professor Henry Snaith’s lab at the University of Oxford. It was originally planned to develop a type of solar cell known as organic dye sensitised.

In 2014, we pivoted the business to focus on capitalising on a new solar material, known as perovskite. By combining perovskite with silicon, we are able to create a tandem solar cell that is significantly more efficient than silicon alone. This perovskite-on-silicon tandem solar cell can generate anywhere from 20 to 50% more energy than any single solar cell.

Our research and development and headquarters are located in the UK, just north of Oxford. Back in 2016, we travelled around the world looking for a location for a pilot and production line. We were seeking an existing high tech manufacturing factory that we could acquire at low-cost, and adapt to our needs. We identified this site in Brandenburg an der Havel, Germany, early on; a thin-film solar plant, owned by Bosch and for sale. A deal was struck, and we obtained the title deeds in May 2017. Within months, with modest changes to the existing equipment, we were producing our full-sized tandem solar cells, albeit at limited quantities.

You might have seen that we recently set the record, for the highest certified efficiency of any commercial-sized solar cell at our factory, with a 28.6% efficiency. I am proud of that product. We have a roadmap to take the efficiency even higher in the future.

We begin by acquiring the raw silicon wafers, and then we fabricate the bottom silicon solar cell, a heterojunction solar cell, in-house. Following this, we add our additional perovskite solar absorber materials, less than one micron in thickness, directly onto the silicon solar cell. Finally, we finish by metallising the front and back of the tandem cell, in order to wire and assemble them into modules.

One of the problems the industry is facing is sourcing the raw materials, and in particular, the silicon wafers. All of our customers are concerned about the supply chain, and making sure it’s free of forced labour; in some cases, they would like to see it free of China. That is of course a very difficult thing to achieve. As of 2022, China supplies 80% of the world's solar PV modules, including the polysilicon and wafer supply.

At the moment, the factory has a production capacity of <50MW of tandem solar cells annually. That is quite small in the realm of PV production or demand, but significant for a new technology. In terms of volumes, the original factory plan was to produce 250 MW. Since we did not acquire all of the equipment that we had hoped for because of a problem with the equipment supplier, we can’t reach that capacity today. Of course, we want to expand that capacity.

All of our energy is procured from green energy suppliers; all of our electricity comes from certified green electricity which in Germany is not that hard to acquire. 

Overall, the company employs about 150 people; it’s divided with about one third based at the research and development headquarters in the UK, and the other two thirds based in Germany. 

We draw upon the local community for staffing, especially for operators, but of course recruit globally for engineers. In 2017, we hired back a dozen or so of the former Bosch employees previously based at the factory site. One of the attractions for choosing Germany was the availability of skilled labour, including those with solar experience.

We’ve met all of our commitments for hiring the necessary staff to meet the subsidies that we received from the National Joint Federal/Länder Task for the Improvement of Regional Economic Structures (GRW), and the Brandenburg State. Since 1969, the GRW has been working to boost investment activities, and generative attractive local jobs across German regions.

We will be expanding, and hiring more people as we go forward. For new factories that we build, wherever they may be, at the multi-GW level, they typically will require 160 production people per GW of annual capacity. 

In principle, this concept of energy security, was not high on the list of things we were thinking about before. We were simply trying to deploy our technology. Now however, it’s pretty clear that energy security is important. You definitely don’t want to have your energy supply controlled by someone else.

15/20 years ago, Europe, and in particular Germany were the premier solar manufacturing suppliers. All of the tools and equipment capability came from Germany. Then China came in, and now, is by far the world leader in the manufacturing of solar today.

It is important to remember, that the bulk of the solar module’s weight consists of glass. In fact, a typical module for a rooftop weighs 22-24 kg. Of that weight, 700 grams are comprised of the solar cells,  a very small fraction. Right now, you’re shipping 24 kg of glass to hold 700 grams of something that actually does the work, all the way from China. A significant part of the carbon footprint comes just from the shipping. We have to make sure that we have the full European supply chain worked out, to build the entirety of the assembled modules in Europe, and that includes making the glass.

We need to get regulators and politicians working together, and not slow things down. We spend a lot of unnecessary time getting permits and approvals. One of the messages we have been sending to the local government, is to make things streamlined so that we can get these factories installed faster.

And for us in particular, it is a supply issue, can we get the equipment we need to build the factories, because we’re being told that there are delivery lead times of 1-2 years from European suppliers. And the Chinese counterparts are saying, the equipment is in stock. That’s a real dilemma, if you want us to build a factory in the next 2 years, we have to site it, build it, permit it, and outfit with equipment. 

In terms of what we’re trying to achieve, we have the same common mission I think everyone in the renewables sector does, we think we can change the world. It sounds far-fetched but it’s not. We’re trying to help decarbonise and deal with the energy transition, even if we do it initially at a smaller scale. Our perovskite tandem solar cell is so unique, that eventually we would hope it would become the mainstream solar product by 2030, and beyond.

Over the next couple of years, we want to build more factories, hopefully much larger than 1 GW in output, and in fact produce multiple GW of solar cells. Remember, the future is all electric.