A method and device for the wireless transmission, in closed spaces, of energy emitted by at least one light source. The energy emitted by the light source is received by at least one solar cell module in the closed space and is converted into electricity. The method includes the steps of reflecting at least a part of the light energy emitted by the light source at a reflective surface inside the space, receiving the reflected light energy in the at least one solar cell module, and converting the reflected light energy into electricity. The device includes at least one solar cell module inside the closed space, configured to receive the light energy and convert the light energy into electricity. At least a portion of the space comprises a reflective inner surface comprising a multilayer insulation surface, at which the energy emitted by at least one light source is reflected.