Liverpool University has unveiled details of a cheap, safe replacement for one of the highly toxic and expensive substances used to make thin film solar panels.
Many thin film solar panels contain cadmium telluride – a heavy metal that is quite dangerous. Additionally, calcium chloride is added to the cadmium telluride to boost efficiency.
Calcium chloride is expensive to produce and also highly toxic, requiring safety measures during manufacture and subsequent disposal when the panels are damaged or reach the end of their service life.
University of Liverpool researcher Dr Jon Major has discovered calcium chloride can be replaced with magnesium chloride, a substance used to make tofu and bath salts.
Magnesium Chloride can be extracted from seawater, is safe and costs around a tenth of a cent to produce; compared to approximately 3 cents a gram for calcium chloride.
“Cadmium chloride is toxic and expensive and we no longer need to use it,” says Dr. Major. “Replacing it with a naturally occurring substance could save the industry a vast amount of money and reduce the overall cost for generating power from solar.”
While the use of magnesium chloride still doesn’t address concerns about cadmium telluride, it’s certainly a step in the right direction and Dr. Major has already reached out to major thin film solar manufacturers.
Dr Major’s research was funded under a grant from the Engineering and Physical Sciences Research Council (EPSRC) and the University of Liverpool. His findings have published in the journal Nature.
Not all thin film solar modules use cadmium telluride. An example are Solar Frontier solar panels, which use CIS (copper, indium, selenium) and offer one of the highest conversion efficiencies of any commercially-produced thin-film module on the market.
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