Low Impact

Solar cell technology isn't standing still

We hear about all the money being invested in “clean coal” nowadays, and very little about developments in the renewable sector. You’d be forgiven for thinking that green technologies are a little stagnant right now. I mean, there’s only so much you can do to improve on a turbine to catch the wind, or a wafer of silicon to catch the sun, right?

But there’s a lot of energy (excuse the pun!) going into building better, cheaper and more efficient green energy sources. A great example of this is in an article published recently on IEEE Spectrum entitled “First Solar: Quest for the $1 Watt“.

The article describes some of the technology behind the media-shy “First Solar” company. They are working on (and selling) photovoltaic solar cells that are made not of silicon, but of cadmium telluride. Through this material, and the production process they have developed, they’ve gained a number of advantages over the more standard crystalline silicon cells.

• They only need to use 1% of the thickness of a normal solar cell of cadmium telluride, so less material is needed.
• The cells are built on top of glass panels so large panels can be built relatively easily.
• The manufacturing process only takes 10% of the time of normal solar cells.

The technology isn’t as efficient as crystalline silicon at converting sunlight into electricity, so you need larger areas of cells to produce the same amount of electricity. This puts these cells at a disadvantage when it comes to urban installations where the available (and suitable) roof space is usually quite limited, but this isn’t so much of a problem for commercial solar farms. These installations are designed to feed megawatts of power into the grid and are typically located on large areas of land, and therefore have less space constraints.

Things must be looking pretty promising for this technology – according to their recently released financial results, First Solar’s revenue jumped around 30% this quarter from last quarter. But that’s not to say that they’re the only players in the solar innovation arena. There’s a number of other innovators out there, all of whom have a different angle on improving the cost and efficiency of solar.

Origin Energy are working on “Sliver Cells” – fine “slivers” of crystalline silicon that are meant to be more efficient at gathering sunlight, work better in partially shaded settings, and use up to 90% less silicon than standard cells. Other companies are working on amorphous silicon on a glass substrate which also uses very small amounts of silicon. Still other companies are trialling various exotic compounds in the search for materials that are more efficient at turning sunlight into electricity.

It’s unlikely that only one technology will prevail. More likely is a selection of offerings, each with its own strengths and weaknesses for different applications. Whatever technologies emerge, solar photovoltaics is an exciting field, and one that has the potential to become more and more lucrative as countries start to factor in a price on the carbon that their more traditional power plants emit.

Categories: current affairs, energy, environment, green, solar

Tags: solar