Sunday, January 12, 2014

Thinner solar cells could be the next big thing

Most technological innovations aimed at improving solar cells have focused primarily on increasing the efficiency of their energy conversion, or on lowering the cost of manufacturing. However, there is another approach coming from MIT researchers that are aiming to produce the thinnest and most lightweight solar panels possible.

These extra thin solar panels have the potential to surpass any substance other than reactor-grade uranium in terms of energy produced per pound of material. The MIT researchers also stated that they could be made from stacked sheets of one-molecule-thick materials such as graphene.

Using two layers of one-molecule-thick materials it is possible to create solar cells with 1 to 2 percent efficiency in converting sunlight to electricity, That's pretty low compared to the 15 to 20 percent efficiency of standard silicon solar cells but the plus side is that is being achieved using material that is thousands of times thinner and lighter than tissue paper. The two-layer solar cell is only 1 nano-meter thick, while on the other hand conventional silicon solar cells are usually hundreds of thousands of times that. The stacking of several of these two-dimensional layers could boost the efficiency significantly thus being able to compete with conventional technologies.

There are certain applications where weight is a crucial factor –this include spacecraft, aviation or for use in remote areas of the developing world where transportation costs are significant, and in these cases using these lightweight cells could be far more beneficial than sticking with conventional technology.

If we were to measure things pound for pound these new solar cells would produce up to 1,000 times more power than conventional photovoltaics. Being so thin makes it advantageous in shipping, but it also makes ease of mounting solar panels and when you consider that half of the costs of today's solar panels are in support structures, installation, wiring and control systems, going for these cells could significantly reduce the total costs.

The fact that cannot be ignored either is that the material itself is much less expensive than the highly purified silicon used for standard solar cells and since the sheets are extra thin, they require only minuscule amounts of the raw materials.

The additional advantage of these materials is their long-term stability, even in open air, while other solar-cell materials must often be protected under heavy and expensive layers of glass. These materials have proven to be quite durable as they are stable in air, under ultraviolet light, and even in moisture.

The researchers are yet to turn computer models into actual production but the potential is certainly there. Perhaps this is the first step to a new trend in solar energy industry, creation of extra thin solar cells.

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