An arrangement is disclosed for supplying power to a field device used to monitor an industrial process in a plant, having an enclosure and a wireless communications interface for data communications with a central data-processing device, and having a thermoelectric converter, which converts an existing heat flow between two points at different temperatures into electrical power and supplies this power to the field device. The thermoelectric converter is arranged in a separate enclosure from the field device, and transfers the electrical power to the field device by means of electrical wires or wireless transmission.