IEA (2022), Contribution of renewable and non-renewable electricity and ambient heat from ground, water and air to heat pump output in buildings space heating in the Net Zero Scenario, 2010-2030, IEA, Paris https://www.iea.org/data-and-statistics/charts/contribution-of-renewable-and-non-renewable-electricity-and-ambient-heat-from-ground-water-and-air-to-heat-pump-output-in-buildings-space-heating-in-the-net-zero-scenario-2010-2030, Licence: CC BY 4.0