Tofu could be solar power’s missing ingredient

A major component holding back the solar industry's drive towards multi-surface flexible panels is the necessity for cadmium chloride, which is both expensive and toxic. New research from British scientists at the University of Liverpool, however, has the potential to remove its requirement and, in doing so, reduce the cost and toxicity of the product.

The alternative they have discovered is already present in various products on the market, although completely unrelated to sustainable energy. Magnesium chloride is indeed so banal that it is used to turn soy milk into the meat alternative tofu, as well as being used in baths salts and de-icer. The most recent discovery, however, could have a far more meaningful impact.

The silicon semi-conductors currently in use in around 90% of solar panels convert sunlight directly into electricity, but with poor absorptive quality. The current evolution seeks to use PV Cells with a thin coating of cadmium telluride - the limiting factor thus far having been the expense and toxicity created in the application of the cadmium chloride. The impact, however, could see the efficiency of the conversion from sunlight to electricity head upwards of 15pc from just two percent.

The new discovery of using magnesium chloride as an alternative could greatly accelerate the progress of making solar energy at least as cost effective as fossil fuels. The effectiveness of coating the cadmium telluride with the magnesium chloride is said to be at least on a par with the cadmium chloride. The major factor is that the magnesium chloride can be applied without any special measures and minus the detrimental consequences of the current process. Indeed, during trials, scientists used a simple spray gun purchased for under £50 for the job.

The cost and complexity of using the cadmium chloride is apparent during the application process, whereby toxic cadmium ions are liable to be taken away by water; this leads to the requirement of fully filtering all waste water, whilst workers have to wear special protective clothing. Although the cadmium layer is not toxic in the final panel, it is the expense of this process that will be removed through the development of an alternative.

The chairman of the renewable energy firm Solarcentury, Jeremy Leggett, believes that the increased competitiveness the new discovery could bring to solar energy could result in the "death spiral" of current utility business models. The impact on costs in the sector is highlighted by the fact that magnesium chloride is about 1% the cost of the cadmium. This is on top of savings made during the application process.

Not only will this new generation of solar panel be more cost and energy efficient, but also, with a vastly reduced thickness, could even be purchased by the roll. This enhances the variety of situations and locations solar energy could be used in, and will make it especially useful in emergencies. They also don't require the same degree of direct sunlight and can thus be used in areas previously not applicable.

Despite the fact that there are still numerous hurdles to overcome, such as the ability to mass produce high efficiency units, this new discovery could well be an important stride forward in the development of solar energy.