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Renewable energy

Printable solar cells

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Paper thin solar cells on paper can now be produced with inkjet printing. This will allow solar cells to be much cheaper and be placed almost anywhere.

It may still seem far fetched to imagine our houses powered by solar cells in curtains, blinds and windows. But some scientists say it will eventually be possible to print photovoltaic elements on a huge range of surfaces and materials – creating cheap, printable solar cells in place of more costly silicon panels.

Printable solar cells offer exciting potential for generating electricity more flexibly and at a lower cost, wherever the sun shines. In the traditional silicon solar PV we see on people’s rooftops, the most costly component is the silicon material that holds the photovoltaic elements. Silicon is abundant and non-toxic, but it is expensive to process into wafers for traditional rooftop solar PV panels.

New developments in printed solar cells could allow solar energy to be cheaply and easily converted into electricity almost anywhere, including walls, windows, roller blinds, shade umbrellas, and even tents.

The idea of using your tent to harvest power on trips to the beach or a camping weekend could really propel glamping (glamorous camping) to the next level, with free on-site electricity powering life’s little luxuries!

towards commercially viable printable solar cells

Currently, printable solar cells have only reached about 10 per cent efficiency, whereas traditional silicon solar PV cells are closer to 25% efficient. The life span of the printed solar cells is also only six months. So researchers are working to increase their efficiency, weather-resistance and life span to reach commercial viability.

In late 2014, a consortium from Australia’s Commonwealth Scientific and Industrial Research Organisation (CSIRO), the University of Melbourne and Monash University announced that their printable solar cells were on the verge of commercialisation.

A team of 50 chemists, physicists and engineers – working together since 2007 – hope to see printed solar panels used in low-power applications within the next few years.

CSIRO photovoltaic expert Dr Fiona Scholes explained the team hoped they could achieve a similar power delivery at a significantly reduced cost.

“Silicon is falling in price, but think about how cheap plastic is. The ink is a negligible cost, so the raw materials are very cost effective. This is a big step forward because you can put these cells anywhere you can think of. Also the consistency is better than silicon – they work well in cloudy conditions,” said Dr Scholes.

The CSIRO’s Scholes said although silicon cells are still on top of the market, she predicts printed solar cells will be “a key part of the renewable energy mix”. While the team can’t produce the cells commercially itself, a number of manufacturing companies are stepping forward.

How are printable solar cells made?

At the moment, printable solar cells are made by printing a specially developed ‘solar ink’ onto plastic film, similar to the way plastic bank notes are printed.

Whatever the method or the materials used, the solar principles remain the same:

  • Incoming photons free electrons and send them scattering through the solar cell’s material before being channelled into an electrical circuit.
  • The efficiency of the solar cell depends both on how well the material captures light to set these electrons free, as well as how effortlessly the electrons travel through the material.

Researchers such as the Victorian Organic Solar Cell Consortium are developing processes for printing solar cells onto all manner of surfaces using various printing, dyeing and spraying techniques. The solar cells can be printed straight onto paper-thin, flexible plastic, as well as onto steel, and can be made semi-transparent for building cladding and windows.