Method for the evaporation and/or distillation of liquids with the assistance of a heat pump, the heat pump comprising a refrigerant evaporator where the refrigerant is heated and evaporated by the heat retrieved from a natural energy reservoir; a refrigerant condenser, where the refrigerant is cooled and recondensated by the liquids being evaporated and a refrigerant compressor there between, the refrigerant condenser having an inlet and an outlet, the method comprising: - supplying the liquids to be evaporated to an inlet of a liquid evaporator; - evaporating said liquids in the liquids evaporator by the heat released from cooling and recondensing the refrigerant in the refrigerant condenser, wherein the heat pump's refrigerant condenser and liquids evaporator comprise a heat exchanger and wherein the evaporation pressure is reduced with either a pressure reduction valve fitted on the inlet side of the liquids evaporator or by means of natural resistance at the inlet of the evaporator together with an evaporated liquids a compressor for suction of the evaporated liquids from the evaporator, the method characterised by the step of: - further heating the evaporated liquids that have exited the liquids evaporator outlet before the evaporated liquids enter the evaporated liquids compressor in a separate heat exchanger situated upstream of the evaporated liquids compressor and downstream of the liquids evaporator outlet to eliminate saturation of the evaporated liquids before the compressor, wherein the separate heat exchanger comprises a heater element, an evaporated liquids inlet in fluid communication with the evaporator outlet and a heated fluids outlet in fluid communication with the compressor, said heater element, forming the first stage of the condenser thereby utilizing the peak temperature of the refrigerant when it leaves the heat pump's refrigerant compressor to provide further heating of the evaporated liquids leaving the liquids evaporator in the separate heat exchanger. - supplying the liquids to be evaporated to an inlet of a liquid evaporator; - evaporating said liquids in the liquids evaporator by the heat released from cooling and recondensing the refrigerant in the refrigerant condenser, wherein the heat pump's refrigerant condenser and liquids evaporator comprise a heat exchanger and wherein the evaporation pressure is reduced with either a pressure reduction valve fitted on the inlet side of the liquids evaporator or by means of natural resistance at the inlet of the evaporator together with an evaporated liquids a compressor for suction of the evaporated liquids from the evaporator, the method characterised by the step of: - further heating the evaporated liquids that have exited the liquids evaporator outlet before the evaporated liquids enter the evaporated liquids compressor in a separate heat exchanger situated upstream of the evaporated liquids compressor and downstream of the liquids evaporator outlet to eliminate saturation of the evaporated liquids before the compressor, wherein the separate heat exchanger comprises a heater element, an evaporated liquids inlet in fluid communication with the evaporator outlet and a heated fluids outlet in fluid communication with the compressor, said heater element, forming the first stage of the condenser thereby utilizing the peak temperature of the refrigerant when it leaves the heat pump's refrigerant compressor to provide further heating of the evaporated liquids leaving the liquids evaporator in the separate heat exchanger.