Abstract: A power receiver (301a, 301b, 301c, 301d, 301e, 301f) is disclosed herein. In a specific embodiment the power receiver has a first electrode (300) arranged to be electrically coupled to a body (105) of a living being, the first electrode (300) operable to receive an electrical signal via the body; and a rectifier (307) for rectifying the electrical signal into a rectified electrical signal. The rectifier (307) includes a plurality of rectifier switches and operable in a bulk biasing mode in which first selected rectifier switches of the plurality of rectifier switches are forward bulk biased. A power transmitter (201), an energy transfer apparatus (100) and a method of transmitting electrical power are also disclosed.