Abstract: Method and device (100) for purifying and bringing water up from a water body (50), the device including: a hollow, vertical structure, having a first space (110) with a supply opening (112) for water to be purified; a boiling device (111) for such water which is driven with light from an optical fiber (12); a condenser (133) for condensing water vapour from the boiling device; a container (131) for condensed water, which container is connected to the condenser; and a conduit device (120) for water vapour between the space and the condenser. The space communicates freely with the water body. The outlet of the container is arranged above a heating location in the boiling device.

Abstract: Device for purifying water, including a hollow structure in turn including a first space, includes a supply opening for water to be purified and a boiling device for such water, arranged to heat the water to the boiling point using energy from focused sunlight supplied via a supply device for sunlight to a heating location in the first space; a condenser for condensing water vapour from the boiling device; and a conduit device for water vapour, arranged to bring water vapour from the first space to the condenser. The heat exchanger is arranged to transfer thermal energy from either hot water vapour which has been boiled off in the boiling device or condensed water which is still warm and originates from such vapour, to water to be purified and which is to be introduced into the first space through the supply opening. A method for purifying water is also described.