Renewable energy account for around 22% of global power generation, but this share is expected to double in the next 15 years, partly due to the rapid growth of variable renewable energy from solar photovoltaics and wind. This IRENA/IEA-ETSAP Technology Brief provides an overview of the main performance and costs of technologies that are used to support renewable energy grid integration, an overview of the shares of variable renewable energy across the world, and existing operational experiences in continental and island systems.