The role of storage technologies for the transition to a 100% renewable energy system in Europe

Abstract

A transition towards a 100% renewable energy (RE) power sector by 2050 is investigated for Europe. Simulations using an hourly resolved model define the roles of storage technologies in a least cost system configuration. The investigated technologies are batteries, pumped hydro storage, adiabatic compressed air energy storage, thermal energy storage, and power-to-gas technology. Modelling proceeds from 2015 to 2050 in five-year time steps, and considers current power plant capacities, their corresponding lifetimes, and current and projected electricity demand to determine an optimal mix of plants needed to achieve a 100% RE power system by 2050. This optimization is carried out with regards to the assumed costs and technological status of all technologies involved. The total power capacity required by 2050, shares of resources, and storage technologies are defined. Results indicate that the levelised cost of electricity falls from a current level of 69 €/MWhe to 51 €/MWhe in 2050 through the adoption of low cost RE power generation, improvements in efficiency, and expanded power interconnections. Additionally, flexibility of and stability in the power system are provided by increasing shares of energy storage solutions over time, in parallel with expected price decreases in these technologies. Total storage requirements include up to 3320 GWhe of batteries, 396 GWhe of pumped hydro storage, and 218,042 GWhgas of gas storage (8% for synthetic natural gas and 92% for biomethane) for the time period depending on the scenario. The cost share of levelised cost of storage in the total levelised cost of electricity increases from less than 2 €/MWh (2% of total) to 16 €/MWh (28% of total) over the same time. Outputs of power-to-gas begin in 2020 when renewable energy generation reaches 50% in the power system, increasing to a total of 44 TWhgas in 2050. A 100% RE system can be a more economical and efficient solution for Europe, one that is also compatible with climate change mitigation targets set out in the Paris Agreement.