Different storages and different time-variable operation modes of energy storages in future electricity markets

Future energy systems are expected to be driven by the political and societal objective of slowing down climate change and therefore characterized by a high share of renewable feed-in. In the mid and long term, storages will be one option to deal with the reduced flexibility from conventional power plants to ensure coverage of demand. While conventional generation has mostly given marginal costs and an associated “merit order” in the supply stack, the value of the storage content changes during storage operation and so does its position in the supply stack. Based on an analytical approach for solving a linear energy system model, the key aspects of the changing operation modes of storages and implications for the refinancing of investment costs are investigated. This is highlighted for a selection of case studies including pumped hydro, Li-Ion batteries and power to gas as storage technologies.