Do variable renewable energies endanger the power system? - An approach to measure flexibility

Balancing of electricity supply gets more difficult due to increasing shares of volatile renewable energy. Based on hourly solar and wind power generation and load data, hours with the largest deviation between forecasted and actual load and variable renewable energy power generation are identified. The power system's flexibility is measured at the level of the power system's components: generation, cross-border transfers, market and operation. To depict the still available flexibility in critical times at the component level, the actual use of flexibilities in critical hours is compared to the available flexible potential. The results show that most countries dispose of sufficient generation and transmission flexibility as well as of market and operational flexibility.