Flexible solar cells may be rollable, typically organic OPV from companies such as Opvius Germany, the new more efficient leadperovskites a form of Dye Sensitised Solar Cells DSSC being commercialised by Solliance, EPFL and others and, most efficient of all GaAs, from Hanergy subsidiary Alta Devices. On the other hand, there are versions that are only bendable, such as copper indium gallium disulfide CIGS from Midsummer Sweden and others, versions of amorphous silicon and – only slightly bendable – some polysilicon and single crystal silicon PV and also cadmium telluride from Polysolar UK. The new IDTechEx report, “Toxicant Materials in Electronics/ Electrics 2018-2028” notes that lead perovskites, GaAs and CdTe employ poisonous materials or can break down to form poisonous materials, usually in quantities so small that disposal in landfill is permitted. In the case of CdTe, controlled disposal at end of life may be required when large amounts are used. IDTechEx does not recommend that any of these be banned on current evidencebut toxic ruthenium-based CIGS is now unnecessary. Other factors such as frequency tuning for solar windows, cost-efficiency compromise and attractive colours provide market space for all versions.
The non-poisonous versions are proof against future regulation and probably more widely applicable. These are OPV, CIGS and mostsilicon now biocide silver is largely absent from it. Meanwhile it is good to see non-toxic CIGS prospering, from the hurricane proof flexible panels on MIT mobile desalinators in Puerto Rico – even working with a tree penetrating them – to Midsummer in Sweden doubling employees in 2018. Midsummer revenues for 2017 increased by 94% to $14 million and profits before taxes increased by 135% powered by orders for the company’s compact DUO thin film solar cell manufacturing system and a positive market response to its new Building Integrated Photovoltaics BIPV business concept.
NREL, Solliance, EPFL and IDTechEx speak on the various new forms of flexible photovoltaics at the conference “Off Grid Energy Independence” at the large “IDTechEx Show!” in Berlin, April 11-12 where exhibitors and other conference streams cover manufacturing technologies for flexible solar and more. See www.idtechex.com for more.