Photovoltaics: The underestimated technology


Solar cell in the Competence Centre Thin-Film- and Nanotechnology for Photovoltaics Berlin (PVcomB)

According to new studies, solar power could become the pillar of our global power supply

This is a conclusion that is sure to liven up the political discussions: the percentage of photovoltaics in our global power production is growing much faster than anticipated in previous forecasts. The assumption had been that solar power would make up five to seven percent of the energy supply by 2050 – in reality, however, it is more likely to make up 30 to 50 percent. That is the result of a study undertaken by the MCC (Mercator Research Institute on Global Commons and Climate Change), which was published in the journal “Nature Energy”.

“The argument so often heard, that an energy transition based on solar power would be too expensive, is wrong,” says Rutger Schlatmann. The director of the “Competence Centre Thin-Film- and Nanotechnology for Photovoltaics Berlin” at HZB has been working on solutions for low-cost photovoltaics for a long time. “The costs have dropped dramatically over recent years. This comes in part from better technology, but also from larger production volumes and improved manufacturing methods,” he says. The large-scale production of solar electricity in Germany costs only six cents per kilowatt hour, Schlatmann tells us, and thus less than producing electricity from fossil fuels like oil, gas or coal. And that is even before factoring in the secondary costs of electricity from fossil fuels.

The MCC study says that the price of solar modules drops by 20 percent with every doubling of production. The task now is to establish more stable grids and larger storage capacities. This is a task for the political decision makers, who are faced not only with technical challenges but also with major opportunities. The results of the MCC study are being included in the next IPCC Assessment Report, which means they will form a basis for future political decisions.

Rutger Schlatmann from HZB also refutes another argument one still often hears: that photovoltaic systems take too long to generate enough electricity to cover their own manufacturing costs. “If the solar system is put up in a sunny position facing south,” Schlatmann explains, “then the so-called energy payback time is less than one or two years. Even in unfavourable conditions, it takes less than four years.” On top of this, solar cells remain in service for 25 to 30 years.

The authors of the study warn against bad investments and missed business opportunities – these risks will exist as long as important players such as the International Energy Agency continue to underestimate the contribution of solar energy towards climate protection. “So that we can have a stable power system with 20 to 30 percent photovoltaic electricity within 15 years, we have to set ourselves on the right course now,” reasons co-author of the study Robert Pietzcker of the Potsdam Institute for Climate Impact Research. His conclusion: “Our study shows that photovoltaics can develop from a niche technology into the main pillar of an environmentally friendly and low-cost power supply.”