By Nick Gilbert
Researchers at the Chalmers University of Technology conducted a study on issues related to materials for Concentrating Solar Power (CSP). They found that solar thermal power does not seem to be affected significantly by the availability of materials.
Parabolic trough collectors at the PSA, Plataforma Solar de Almeria, experimental facilities in Spain. Concentrated sunlight heats up a synthetic oil in the pipes at the focus of the troughs. Photo: Erik Pihl
Renewable energy technologies such as wind and solar energy extensively use certain rare earth metals. The availability of these materials, including indium, may be affected by export restrictions for rare earth elements declared in China. The associated industries are trying to restrict usage of the necessary rare earth metals.
CSP technology utilizes glass and steel, which are quite abundant. When considering global reserves, there seems to be sufficient availability of these materials for CSP. However, demand from other industries may lead to a short supply of silver which is being widely used for reflecting surfaces in CSPs. The manufacturers of reflective mirrors may opt for aluminum and other cost-effective materials.
eSolar and Cobra manufacture tower and trough solar plants. These plants use concrete, iron and nitrate salts. High quality steels are required for generation of high temperatures. However, the industry may face restrictions due to availability of niobium, molybdenum and other alloys.
Heliostat tower plants require large amounts of stainless steel and aluminum, while parabolic trough plants require large amounts of iron and concrete. When compared to salt-receiver tower plants, the parabolic trough plants require more molten salt.
A growth scenario from Greenpeace/IEA SolarPACES/ESTELA forecasts that in 2050, CSP may reach 8000 TWh per year. At that time, up to 15% of materials including magnesium, molybdenum, nickel and glass, and around 50%-120% of the current annual nitrate salt production will be required for solar plants. In order to address the increasing demand, the production of nitrate salts should be increased and a substitute for silver must be found.