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In a 24 hour whirlwind trip to Switzerland, I visited the headquarters of technology start-up firm SwissINSO, where I was able to see first hand the development of a new technology that is set to bring more colour to the PV market, specifically the BIPV and solar thermal sector.

On 14 May, the company in collaboration with the Swiss Polytechnic Institute (EPFL) launched a new patented coating technology, which can be used to create solar panels in a variety of colours, upping the aesthetics in BIPV projects to a whole new level.

Following more than ten years of research and development and investments worth up to several millions of euros, SwissINSO in collaboration with EPFL, has finally brought the technology from a lab concept to commercialisation.

By using the innovative Kromatix technology, SwissINSO is now able to supply PV module manufacturers with a piece of opaque, coloured glass that can be integrated into any manufacturers’ modules — including thin-film, crystalline and solar thermal modules — without compromising on performance.

The technology is applied to glass by combining two different surface treatments. The inner side of the glass is subjected to a coloured nano-scale multi-layered treatment using a vacuum plasma process while another treatment is used to modify the glazing of the outer surface. The company explained that these treatments can prevent glare effects as well as remove the visibility of the technical components, such as the cells and wafers of PV or those in solar thermal units, which can normally be seen.

Speaking to PV-Tech, Rafic Hanbali, CEO of SwissINSO, explained that the technology would require “minimal interruption” to a module manufacturer’s production line. The coloured glass provided by SwissINSO is suitable for all types of modules and is incorporated into the module by the module manufacturer. Hanbali added that the technology could even be applied to glass produced by a manufacturer of their choice.

Product range and applications

The technology has been optimised for both solar thermal panels as well as PV modules. In terms of energy loss, SwissINSO claim that this could range between 0.5% and 15% depending on the colour.

At a media briefing held at the company’s headquarters, Hanbali said: “The energy loss will depend on the colour you choose. Virtually, we can have any colour except white and sparkling red. We can do sparkling red but we would lose too much efficiency.”

Moreover, the coloured panels can be used to make both solar thermal and PV units look the same, creating new opportunities for architectural design. For example, if integrated PV and solar thermal units were used side by side in one building, the coloured panels would make it difficult for an observer to tell them apart.

Hanbali commented: “For architectural integrity, they are homogeneous, you have the same thing. You wouldn’t know from the outside which is which.”

For façades, the company offers coloured glass for frameless PV modules. Hanbali said: “We can use them on new buildings or as a second skin on existing buildings, with any colour you want and no captors visible.”

Market potential

Since lab concept, SwissINSO’s goal was to create a “marketable product, and not just a product which is beautiful but you can do nothing with”, Hanbali said on the day of the launch.

In order to ensure it was a marketable product, the company carried out numerous industrial runs including tests that measured the durability of the coating, and the degradation of the colour over time.

The results? “The product is feasible in chain production,” Hanbali said. “The aesthetics are exactly the same, the optical properties and efficiency are even better than in the lab.”

But what about cost? This will surely be one of the most important deciding factors for the success of the product. 

According to SwissINSO, the additional cost for coloured PV panels is between US$0.12 and US$0.18 per watt peak for PV panels, and 5% to 10% more for solar thermal panels.

Explaining the range in cost, Hanbali said: “The cost is a chicken and an egg story. For any product and industry, if you want something to cost little, you have to produce a lot. But in order to produce a lot, the cost should be low. So where do you start?

“In PV, our panel will cost an additional US$0.12 to US$0.18 but if someone comes from a solar farm, let’s say it’s 100,000 panels for a 30MW project, the additional cost will be US$0.04 to US$0.05 or even lower. We took an average here, between US$0.12 and US$0.18 cents per watt. There is no way to be precise on figures unless you give me the project.”

With BIPV products already at the higher end of the cost scale, it is difficult to judge if in the current economic climate customers would be willing to part with the extra money.

According to EPFL research, more than 80% of architects would be willing to incorporate solar panels in their buildings if they are offered a good choice of colours and if the price was “reasonable”. In this case, a reasonable cost would be an additional 25%.

With the solar market suffering from overcapacity, many module manufacturers are looking for ways to boost their businesses. One such way, which SwissINSO is banking on to help its business to take off, is to help producers to differentiate their product through colour.

Another way is to go downstream. Hanbali said: “If you want to go downstream, and increase your PV and BIPV residential share, you have to offer something people will accept to put on their house or buildings.”

According to Hanbali, this is one of the key reasons why producers are interested in its technology.   

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