Material Constraints on Technology Evolution: The Case of Scarce Metals and Emerging Energy Technologies
A radical transformation of the energy system in the 21st century will require a large-scale diffusion of a range of new energy technologies. Thin-film solar photovoltaics (PV) and battery-electric vehicles have been suggested as possible major components of a more sustainable energy system. However, some PV and battery designs that are promising in the short term may be constrained in the long term by their requirement for rare metals. Such constraints can materialise in the form of resource scarcity or detrimental environmental effects.
Critical factors that determine metal availability and requirement are identified and quantitatively assessed for four thin-film PV designs and nine batteries. The assessment comprises the elements cadmium, cobalt, gallium, germanium, indium, lead, lithium, nickel, rare-earth elements, ruthenium, selenium, tellurium and vanadium. The technology potentials in terms of calculated material-constrained stocks and growth rates are considerably above current stocks and production levels, but, for many of the technologies, well below the scale of envisioned long-term demand.
Technologies that are promising in the short to medium term but constrained in the long term may function as bridging technologies that pave the way for technologies that are sustainable on the large scale, or as dead-end technologies that lock them out. The outcome is dependent on how the technology moulds the selection environment through a number of lock-in mechanisms. Eight areas are identified, that need to be addressed by policy and far-sighted strategy to increase technology potentials and to form sustainable technological trajectories: (1) efficient materials use, (2) waste mining and stockpiling of rare metals, (3) coordinated policies to escape carbon lock-in, (4) high environmental standards for emerging technologies, (5) continued search for new technologies based on abundant elements, (6) balance between the requirements of cost reductions and sustained technological variety, (7) adjustment of technology expectations to long-term constraints, and (8) repeated monitoring of the process of technical choice and its long-term consequences.