Production of monocrystalline silicon is very energy intensive, and involves emissions of carbon.  There are emerging technologies for reducing carbon emissions and energy use, but they need to be improved if silicon production is to be completely sustainable

New processes such as electrodeposition are now easily able to provide cheaper and more environmentally friendly puresilicon

Chemical reduction processes utilising the catalytic properties of aluminium and manganese can allow the purification processes to operate at much lower temperatures, and these new processes are now commercial available