Start-up Develops Solution for Cutting Down the Amount of Silver in PV Cells

Start-up Story – April 04, 2024

With the rise of PV, the question of how to save on critical raw materials to make PV more sustainable is gaining traction. The technological shift towards n-type cells, which contain more silver than p-type cells, is fueling interest in ways of cutting down the amount of silver used. HighLine Technology, a start-up company from Freiburg, Germany, has found a solution.

Maximilian Pospischil, founder and CEO, explains how it works, what market opportunities he has identified and how the start-up company has evolved so far.

Interview with Maximilian Pospischil, Founder and CEO of HighLine

Mr. Pospischil, can you tell us about your product and about its innovation potential in particular?

Photovoltaics requires a lot of silver. As far as I know, 15 percent of the silver traded globally goes into solar cells, and growing. Ultimately, we will have to find a way to reduce, and even replace, all that silver. We have developed a technology for applying conventional silver paste onto solar cells much more homogenously, which saves around 25 percent of silver.

It goes without saying that the technology would also be applicable to copper or aluminum, if this were to replace silver. We extrude tiny silver conductor tracks on the cells, which is the original application. Also, we have developed complete print heads that can be integrated into conventional production lines. This makes additional applications conceivable, for example connecting solar cells using connective adhesive.

HighLine claims to achieve silver savings of up to 20 percent with its dispensing technology for the metalization of silicon solar cells. What will that mean in terms of costs?

The cost savings will be considerable. Of course, they will vary depending on the price of silver and the order volume. Roughly, you can expect €400,000 per year per print head. In n-type IBC cells, which still use 400 mg, we could save considerably more than in mature products, which only use around 60 mg. We can make the solar cell contacts narrower than you can with screen printing, and we can make them more homogenous.

How much do you expect demand to rise once the ecolabel and other sustainability criteria have been introduced to solar cell production?

There could be another slight rise, but the silver savings in themselves make it worthwhile anyway, mainly because narrower silver conductor tracks lead to efficiency gains. What’s more, with our technology you can print faster, which makes you more productive.

What is HighLine’s commercial potential following the shift to n-type solar cells?

There is no doubt that the increased silver consumption of p-type cells is fueling interest in our technology.

As a start-up, HighLine was supported by subsidies from the High-Tech-Gründerfonds. How did you go about getting start-up funding?

You always have to keep your ears to the ground: How can you find funding, how can you finance the project? We were funded by the EXIST Transfer of Research program of the Federal Ministry for Economic Affairs and Climate Action. The program allowed us to start building a network and to recruit someone who would focus on funding. Then we came across the Fraunhofer Technologie Transfer Fonds, which is funded by Fraunhofer and the European Investment Fund in equal parts. They provided the first financing round using the Start-up BW Pre-Seed program, which put us into contact with subsequent investors. Through Fraunhofer Venture, the start-up department at Fraunhofer headquarters, I had previously been in contact with the High-Tech-Gründerfonds. They found our concept compelling, and we received seed funding.

Even though it’s a mechanical part, our technology is easily scalable, and that gives us leverage. The only risk at this point is that we are not fast enough and that the Chinese will overtake us thanks to their long-term strategy. Our changing policies give us a clear disadvantage compared with China, which has consistently been investing in solar technology since the 2000s.

How exactly does this situation affect your company?

It means that ultimately, you can only attract investors if you can prove contacts with the Chinese market. Investors are not interested in putting their money in a market that doesn’t yet exist, even if Western governments are now showing the political will. This is a key problem: Why invest into a German start-up, if there is no solar industry in Germany?

How strong is the demand for your product from China?

It’s immense. They can feel the immediate effect of saving truckloads of silver. The volumes are vast. The annual production of the major manufacturers may need 50 or 80 tons of silver. These manufacturers want to stay market leaders, and that’s why they need a leading technology. Here in the West, manufacturers must be prepared to invest into a technology, but they will only do that if they are sure that their products will be sold. If the future of the Western market is uncertain, it’s difficult.

What other hurdles are there to bringing an innovative and novel product to the market?

The market launch is still under way. One hurdle is finding the ideal silver paste for our product. It has to fit through our nozzles. So we need paste manufacturers who are prepared to provide the research and development capacity to come up with a suitable paste. Because our paste reduces the need for silver, they must also be prepared to manufacture a paste that will initially take away from their existing business, even if this could give them a long-term competitive edge once our technology becomes established. That’s the technical hurdle.

In terms of the market, there may be trade barriers. For example, the USA have been implementing trade barriers for Chinese companies to give US companies an advantage. But if they are then left with just a couple of companies, there will be no innovative pressure, because they do not have to compete with the Chinese state-of-the-art.

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