Comparing mineral and fossil surplus costs of renewable and non-renewable electricity production

Life cycle assessment aims to assess trade-offs between different impacts, including mineral and fossil resource use. The goals of this study were (1) to derive surplus cost potentials (SCPs) for a large number of fossil and mineral resources and (2) to derive surplus costs per megawatt hour of electricity produced for a range of both renewable and non-renewable technologies. The SCP of a resource refers to the total cost increase over the full amount of resource expected to be extracted in the future, expressed as US dollar (USD) per unit of resource extracted. For the fossil resources oil, natural gas and hard coal, cost-cumulative production relationships were derived that were subsequently used as input to calculate SCPs for these three fossil resources. For mineral resources, SCPs were readily available for 12 resources and platinum-group metals as a separate group. SCPs for an additional number of 57 mineral resources and 4 mineral resource groups were derived on the basis of a statistical relationship between SCP and average price in year 2013. The SCPs of fossil and mineral resources were subsequently used to derive the surplus costs per megawatt hour of 10 electricity production technologies. The surplus costs of electricity production ranged from 0.3 to 148 USD2013/MWh. The three fossil-based energy production technologies, based on coal, gas and oil, resulted in the highest overall surplus costs (23 to 148 USD2013/MWh), while nuclear, geothermal, photovoltaic, wind and hydropower technologies have the lowest surplus costs (0.3-6 USD2013/MWh). We found that the contribution of fossil resource use to the surplus costs was higher compared to mineral resource use, including the renewable energy technologies. Surplus costs of fossil and mineral resources can be used to compare renewable and non-renewable electricity production technologies. This case study shows that fossil fuel use drives the surplus costs of all energy technologies.