DW: Prof Eicke Weber, yYou yourself have traditionally designed semiconductor solar-cells with – the ones in use today. Will they actually be a thing of the past? Are organic cells the future?
Prof. Eicke Weber: Well , there is a opportunity that organic solar cells, solar cells from dye-sensitized materials or from nanostructures can get much better, much cheaper and higher efficient. However, we don't have the technology yet today. We need breakthroughs in this type of technology . We have a group working on it like other groups in Dresden as well. So there is an opportunity but on the way there we need to focus on making current technology cheaper and more efficient and this is chrystalline silicon technology.
But if you look more into the future - you still believe in silicon technology? Will not the organic ones make the race in the long run?
If you ask me, I would not yet put my money into a company for organic materials. But I say that there is a 20-30 percent possibility of a breakthrough that allows us to make solar cells of 40 percent efficiency out of very cheap material. So we really need to do the research. But at the moment, we are having such a quick decrease of the cost of crystalline silicon solar cells that current from the sun produced on your own rooftop now is cheaper than the current out of the wall plug in Germany where we have so little sunshine.
But the organic cells have certain advantages too. You could imagine one day to just paint solar cells on to facades - that's something you couldn't do with silicon.
You have two big problems - one is lack of efficiency and one is a lack of staying power. You know, today's organic solar cells - if you have good materials - can live five years. We have silicon solar cells which were installed 30 years ago and produce still more than 80 percent of their original power. So we are far, far away from this type of application.
But still these solar cell producers with silicon technology are in big problems today - at least in Germany. A lot of them are going out of business. Could the new technology be the ones they get into the saddle back with?
Well, the reason is that the prices came down so quickly that the older German plants couldn't produce at these prices. And I like very much that solar energy gets less expensive, So at the moment, the decrease of price of silicon production whether it comes out of Chinese manufacturing which basically has been delivered by German equipment manufacturers or whether we are able to keep it as well in Germany if we bring together enough invest capital at low cost. Either way, we will have the chance to harvest solar energy. However, we might have the breakthrough in the organic materials and we might change the market in 10, 20 years. But we really cannot predict it - it might happen or it might not happen. The world cannot wait for that.
And will production ever come back to Germany or will Germany just be a place for research in solar technology?
In solar cells, the salaries is just five percent of the total value. That means there is no reason why we should not have cost-effective large-scale production in Germany and Europe. But we have to fight for that.
(Interview: Ingolf Baur)