This report contains the latest developments and good practices to develop grid connection codes for power systems with high shares of variable renewable energy (VRE) – solar photovoltaic (PV) and wind. The analysis is an update of the 2016 International Renewable Energy Agency (IRENA) report Scaling up variable renewable power: The role of grid codes and elaborates on the latest developments and experiences related to technical requirements for connecting VRE generators and enabling technologies such as storage, electric vehicles (EVs) or flexible demand and their incorporation in grid connection codes.

There is an urgent need to adopt clean energy solutions to cope with growing demand and replace existing polluting generators. Utility-scale solar PV and wind farms are already operational in many countries with high shares of instantaneous demand being covered by VRE generation. An increasing number of countries aim to replace fossil fuel-based generation with more VRE generation,1 which would lead to almost 100% renewable power in those countries before mid-century. An advantage, especially for solar PV, is that renewable energy can be deployed at lower voltage levels for direct consumption, with high demand correlation.

Renewable energy is also inexpensive in the long run, producing affordable electricity. Wind power, though deployed at sites away from load centres, can be transported using transmission lines. Alternatively, it can be stored at site using energy storage solutions that could cover for peak loads or as required by the system operator.