The innovation will allow for repeat use of components which make up 65 % of the costs of the batteries (the remaining 35 % is accounted for by glass and aluminium).

    The basis for the technology is pyrolysis, used at high temperatures to decompose organic materials in the absence of oxygen. In petrochemicals, pyrolysis is used to produce ethylene from ethane and for subsequent production of polymers.

    Thanks to pyrolysis, Rosi Solar was able to isolate metals from solar battery cells. The project was carried out with support from the European Union and from the French conservation group Ademe, the investment bank BPIfrance and the company Veolia Environnement, specialised in introducing clean technologies.

    The procedure launched by the startup aims to solve the problem of recycling used solar panels. Installed capacity of photovoltaic panels in 27 EU countries soared from 31 gigawatts (GW) in 2010 to 158 GW in 2021, according to data from clean energy group Ember.

    With due account for the production cycle of solar panels – extending over 20 to 25 years – the peak of capacity to be taken out of service should occur in the 2040s. According to Rosi Solar, the sum total of panels to be taken out of service in Europe in the period from 2040 to 2050 will rise from 2 million tonnes to more than 10 million tonnes.

    The innovation also stands to make a contribution to the reduction of emissions and increased energy efficiency. The startup estimates that production of 1 kg of silicon from solar panels requires 80 kilowatt-hours (KWh) of power and involves emissions of 50 kg of CO2 – more than is the case for aluminium, magnesium and titanium. The procedure also allows for cheaper production of batteries, as silicon accounts for about 20 % of their cost.

    Unit capital expenditure for construction of solar panels in the EU totals $840 per megawatt (MW), according to figures from the International Energy Agency (IEA), which predicts that this figure will decline to $550 per MW.

    The share of solar generation in the EU in the period from 2010 to 2021 rose from 0.8 % to 5.5 %, Ember reports. In France, where just under 70 % of electricity is produced by nuclear power stations, this share rose only to 2.6 %.