Chapter 4 - The dependency of renewable energy technologies on critical resources

Abstract

The importance of renewable energy systems and their global contribution toward electricity supply is increasing considerably. Concerns persist about whether there are enough raw materials—both in terms of quantity and quality—to produce the required clean energy systems. The entire topic is very complex, as there are a lot of systems with varying material demands. This chapter discusses biomass, geothermal, hydro, tidal, solar, and wind energy systems with regard to their material requirements. It will be shown that biomass, geothermal, and hydro energy systems primarily require construction materials like concrete and rebar. Tidal systems require special corrosion resistance, which is provided by special steels with no or little need for critical materials. For solar energy, only a few special photovoltaic systems depend on critical materials. Only one type of wind turbine is based on rare earth elements containing magnets. The analysis shows that critical resources are used in several clean energy systems, but a major share of systemic alternatives are in operation. These results are flanked by a discussion about the terms “criticality” and “resources” to provide the basis for a more precise understanding of the wide scope that these terms incorporate.