Transmission network loading in Europe with high shares of renewables

The need for long-distance power transfers in the electricity system is being driven by both deeper market integration and the increasing share of renewables in generation. The best renewables resources are often located far from load centres, while variable renewables, such as wind and solar, benefit from smoothing effects when aggregated over large areas. However, the increased usage of transmission infrastructure raises the question of how the associated costs should be distributed. The authors present here the application of an existing algorithm called marginal participation (MP) which can be used to allocate the power flowing through each network asset (lines and transformers) to particular network users. They consider two new methods to extend the MP algorithm to high voltage direct current lines that operate parallel to alternating current networks. They then apply the allocation algorithm to a future scenario with high renewables penetration in Europe in 2050, developed as part of the Smooth PV project. They see a significant increase in network usage, including a rise in the proportion of cross-border flows. The increase in network usage is driven disproportionately by offshore wind, because of its geographical concentration away from load centres.