by Anselm Wohlfahrt

Heliatek sells organic photovoltaic products (OPV) both in the form of finished film modules and the OPV film in its pure form. This allows cooperating companies to integrate organic photovoltaics into glass, metal, concrete or similar components. What are the challenges of such a cooperation? What are the possibilities?

We are planning the commercial sale of our HeliaSol® for mid 2020. HeliaSol® is a ready-to-use organic solar film that can be bonded to existing surfaces. HeliaFilm®, on the other hand, is an integration product for building materials that we will launch later. Our biggest challenge is to commercialize a completely new technology on the market. In addition to production challenges (quality, costs, volume), this also includes setting up sales for a completely new product for which there is no experience. So we really have to do pioneering work in many areas. 

In what way do you accompany the planning of new architectural projects?

We do not accompany architectural projects, but advise our customers and strategic customers on the implementation of pilot projects. Some of these projects have an architectural character, but this is not the only aspect for the use of our films.

Would you say that a change in the planning processes in architecture is necessary in order to integrate both comprehensive and successful photovoltaics in existing and new buildings?

From our point of view, sustainable energy sources should be an integral part of buildings. Solar is ideally suited for this, because it can be integrated into a building from the start or retrospectively or installed on the roof. A comprehensive approach to energy technology in the planning phase helps to create a suitable concept for every building. We welcome initiatives that combine buildings and architecture with modern energy concepts. We offer a novel solution, in the form of a finished solution or for the future as an integrated product. 

Your technology is mainly designed for large-scale applications. Which surface would I need as a consumer, in order to have a reasonable utilisation for your products?

Not necessarily only for large-scale applications. Our standard module, which we are going to launch next year is 2 m long and 0.436 m wide in dimension, i.e. less than 1 m². Therefore we need exactly this minimum space. Larger areas can then be connected in a modular way by connecting several foils in a serial or parallel connection. There are therefore no limits to the size of a system. For 1 kW HeliaSol® you need approx. 20 m² roof space (with distances between the foils). 

With the delivery of your organic photovoltaic components you give a 20 year warranty on your products. What challenges have you been confronted with in terms of longevity during the development of your products?

The biggest challenge is to protect our organic solar cells from moisture and oxygen over the lifetime of a flexible carrier film. Therefore, all layers must be strongly and permanently bonded to each other for at least 20 years in which the films must withstand weathering and mechanical stress and continuously produce electricity in a reliable way. 

The individual layers in the organic solar cell are evaporated in your production in a vacuum at almost room temperature (i.e. vapor deposition). Taking Dresden as an example: Would it be possible to vaporize sandstone, copper roofs or paving stones and use them as solar cells?

No, this would not be directly feasible, because our machines are designed for the evaporation of foils, which are guided through the various evaporator sources in a roll-to-roll process. This is only possible with special roll material with special characteristics.

In the future, you also want to offer films that allow colour variations, different degrees of transparency or an opaque appearance. Which parameters have to be weighed against each other?

Transparency and colouring always influence the performance of the products (efficiency). We must therefore work with the customer to find out which degree of change is necessary and can also be economically viable for the end customer. 

If you drive through Germany today, you often see thermal insulation made of expanded polystyrene, which is cut directly on site with a hot wire. Do you think a future scenario is conceivable in which your solar cells are cut and assembled directly on site or even printed on the facade by a mobile “roll-to-roll-to-facade” printer?

No, that will not be possible. Even if the product looks simple, there is an incredible amount of high-tech and know-how in the product. Many steps are necessary to make a product durable for such a long time: From the evaporation of the organic material to the attachment of the cables. We can only do this here. However, we can manufacture products that are easy for the customer to install on site and are perfectly suited for individual application. We see this as one of the most important advantages. 

In the meantime, there are electricity companies where consumers can have the company’s solar systems installed on their private surfaces. The solar systems remain the property of the company, but the electricity generated can be used completely or partly by the consumer. What motivated Heliatek to choose a business model of selling the products commercially and not to offer electricity from solar systems as a service?

We are a technology company with the clear goal of developing and bringing to market a completely new form of solar energy solutions. This enables other market participants to develop innovative business models through completely new applications. That is why we are sticking to our core competence in organic solar technology.

Why are most of your products thermally recycled after 20 years? Are the materials or components contained not reusable after 20 years?

Thermal recycling, i.e. incineration, is simply the most economically and ecologically sensible way of recycling our films. We use glued plastics which are very difficult to separate and a separation would not make any ecological sense. During the incineration process, additional energy is generated that can be fed back into the cycle. Classical solar modules can be recycled, but there is no practically applied industrial recycling process here, so that many old modules still end up on landfills, with unknown long-term consequences for the environment.

The people behind the Fairphone have tried to make their entire production chain transparent (and fair). Would such an approach be conceivable for Heliatek? 

That’s quite conceivable. At present, we are dependent on very few strategic suppliers who supply us with raw materials of the desired quality and to our specifications. Ensuring the availability of materials is our top priority so that we can ensure offering our products next year. A truly green product such as the one we offer would, however, be best suited to such an orientation, similar to the Fairphone. Our production takes place in Dresden with a very high vertical range of manufacture. The majority of our suppliers come from Germany, some from Europe – all are trustworthy and responsible companies, some of whom we have been working with for a long time.

Where do you see organic photovoltaics in 20 years?

That’s a glimpse into the glass sphere. If we look back, OPV has made great progress in recent years and is on the threshold of commercial use. That alone is a huge step for a young technology. Looking ahead, the technology will certainly mature, i.e. become more efficient, more durable and cheaper. These are prerequisites for becoming competitive and finding our place in the market. The potential of the technology is huge when it comes to applications. It would be a great success for us if the technology could help generate electricity through completely new applications and make power generation more decentralised and sustainable. 

After the Climate Cabinet meeting of the Bundesregierung (Federal Government), the cap for the photovoltaic subsidy of formerly 52 billion Euros was abolished. However, in the future a subsidy for 750 watt systems is coupled with annex rates. How do you reflect the results of the climate cabinet meeting of the Federal Government for your company? 

We welcome all framework conditions that are conducive to photovoltaics. But in addition to the funding mechanisms of the Federal Government, which have been continuously reduced in recent years, we see above all customers and users who are no longer exclusively driven by funding, but by the idea of an independent, decentralized, green energy supply with a high proportion of it being generated by their own production from green solar power. These are drivers that are sustainable and we can offer a solution. 

Mr. Hermenau, thank you for the interview!

Photo: Ralf U. Heinrich

Martin Hermenau is Head of Product Development at Heliatek. Heliatek is the leading company in organic photovoltaic products. In the upcoming year Heliatek will launch their product innovation and is going to bring it to the market for the first time.