Daw'r rhan fwyaf o'r gwres hwn o nwy, ond erbyn 2025, ni fydd unrhyw gysylltiadau nwy mewn cartrefi newydd yng Nghymru i gefnogi ymdrechion datgarboneiddio.
Most of this heat comes from gas, but by 2025, there will be no gas connections in new build homes in Wales to support decarbonisation efforts.