The development of standards will help implement the planned dismantling of power equipment, which is scheduled to take place at the end of the next decade. Chinese regulators estimate that by 2040 the country will have to decommission 530 gigawatts (GW) of solar and wind power plants, which is a little under 50% of the capacity of all RES-based generators operating in China today (1,161 GW, according to IRENA). Meanwhile, equipment manufacturers will have to pivot to producing generators that can be easily dismantled. In their turn, power system operators will be prohibited from throwing out spent modules into industrial landfills. Finally, companies that collect and recycle metal will also take part in equipment disposal.
Industry regulators will have to make a choice of power generator recycling technologies, some of which have already found industrial applications. For instance, Japan’s Itochu and France’s Rosi Solar announced last year the start of a project to extract silicon, silver and copper from used solar panels. To that end, the companies will use high-temperature pyrolysis – a process used to decompose organic and inorganic substances under low pressure in the absence of oxygen. Pyrolysis is used in the petrochemical industry to produce ethylene from naphtha, whereas Itochu and Rosi Solar’s project will employ it to isolate silicon, copper and silver from solar cell glass, with these materials accounting for about 65% of the cost of the solar cells.
The process of recycling power generators will also be facilitated through Siemens Gamesa’s innovation – a special resin for bonding components of wind blades. Upon decommissioning, the blades of the wind turbines assembled with this resin will be placed in a slightly acidic solution, whereupon the resin will separate from the fibre-reinforced composite material. As a result, the blades will split into several components, which will be easier to recycle.
The efforts of Chinese regulators will help reduce carbon footprints, since the production of materials for RES is often very energy-intensive and produces large CO2 emissions. Rosi Solar estimates that the production of 1 kg of silicon for solar panels requires 80 kilowatt-hours of power and generates 50 kg of CO2-equivalent in greenhouse gas emissions.
