Material stocks in global electricity infrastructures – An empirical analysis of the power sector's stock-flow-service nexus

Abstract Electricity infrastructures are key for the provision of crucial energy services and economic prosperity. We investigate the current state and historical development of the global power sector from a “stock-flow-service nexus” (SFS-nexus) perspective. The SFS-nexus emphasizes the interrelations and dependencies between social metabolism (i.e. stocks and flows of biophysical resources), provision of services and societal well-being. Focussing on the most relevant stocks and flows, we quantify the main bulk materials (iron/steel, concrete, copper and aluminium) in power plants, grids and transformers, and fuel use of thermal power plants from 1980 to 2017. We assess the relevance of stocks, flows and related greenhouse gas emissions in the overall metabolism of countries and groupings by politico-economic and geographic criteria. Finally, we empirically explore the relations between material stocks and qualitative indicators for service quality and societal well-being. Globally, concrete stocks (9,000 million tons (Mt) in 2017) are dominated by hydropower, whereas aluminium and copper stocks (181 and 161 Mt, respectively) are mostly comprised in conductors in grids (>80%). 50% of the iron/steel stocks (total: 840 Mt) are incorporated in power plants. Annualized embodied emissions of bulk materials account for less than 1% of fuel combustion emissions from power plants. Material intensities and power generation mixes are highly diverse amongst technologies and countries, respectively. Still, electricity supply quality and well-being indicators on country level are clearly correlated with per-capita metal stocks in electricity infrastructures. We thus showcase how material stock inventories can provide insight into the material basis of societies’ well-being.