Transmission needs across a fully renewable European power system

TL;DR

This study quantifies how transmission infrastructure in a fully renewable European power system can significantly reduce the need for balancing energy, highlighting the benefits of increased interconnection capacities based on extensive weather and demand data.

Contribution

It provides a detailed analysis of the maximum potential benefits of transmission expansion in a 100% renewable European power system using extensive weather data and modeling of hourly mismatches.

Findings

Unconstrained interconnectors could reduce balancing needs to 15%.

Constrained interconnectors at six times current capacity achieve 97% of maximum benefit.

Networked countries require significantly less balancing energy than isolated ones.

Abstract

The residual load and excess power generation of 27 European countries with a 100% penetration of variable renewable energy sources are explored in order to quantify the benefit of power transmission between countries. Estimates are based on extensive weather data, which allows for modelling of hourly mismatches between the demand and renewable generation from wind and solar photovoltaics. For separated countries, balancing is required to cover around 24% of the total annual energy consumption. This number can be reduced down to 15% once all countries are networked together with uncon- strained interconnectors. The reduction represents the maximum possible benefit of transmission for the countries. The total Net Transfer Capacity of the unconstrained interconnectors is roughly twelve times larger than current values. However, constrained interconnector capacities six times larger than the current values are found to provide 97% of the maximum possible benefit of cooperation. This motivates a detailed investigation of several constrained transmission capacity layouts to determine the export and import capabilities of countries participating in a fully renewable European electricity system.