Generating electricity from window panes

Harnessing electricity from our window panes or from paper might sound like something out of a sci-fi film. But solar technology has made huge strides in recent years and is close to realizing some of these ideas.

The first modern photovoltaic cell was created in the year 1954 by the American company Bell Laboratories. The first solar cells were made of silicon and weren't much bigger than a razor blade. They could convert around six percent of the sunlight they received into energy.

Bell’s invention kicked off the buzz around photovoltaic technology, the process of transforming sunlight directly into energy via solar cells. Today, the technology is used in everything, from small devices such as pocket calculators right up to outer space, where solar energy powers satellites.

Surging growth

Photovoltaics only have a market share of two percent in Germany, but the industry is growing rapidly. According to the German Solar Industry Association, in 2011 Germany reached a new record by producing almost 70 percent more solar energy than in the previous year.

The trend is likely to continue. In May last year, the German government voted to phase out nuclear energy as soon as possible and accelerate the move towards renewables. The goal is to double the current share of installed renewables in Germany's energy mix to 35 percent by 2020. And to reach that target, solar and wind power will need to play a significant role.

Globally, the solar energy outlook is also growing ever brighter. According to a recent study by Swiss financial institution Bank Sarasin, photovoltaic technology could generate 620 gigawatts of electricity by the year 2020 – a figure that is equivalent to the capacity of 440 major nuclear power plants.

And that jump in solar capacity would be astonishing considering that by the end of 2010, solar cells could only achieve 42 gigawatts.

Organic photovoltaics – solar cells of the future?

Silicon solar cells are used in common devices such as calculators

Silicon has dominated the solar cell industry until this point. Some 90 percent of today’s solar cells are produced with the material, says the Fraunhofer Institute for Solar Energy Systems, or ISE.

But the race to find an alternative is heating up around the world, and for good reason: silicon carries significant disadvantages. The rare earth minerals used in solar technology are expensive and toxic and it's difficult to recycle them, making the product not particularly eco-friendly. So researchers are exploring other possibilities in the hopes of finding a cost-effective and efficient alternative.