  We propose using the temperature gradients between the Moon's surface and the
soil at a certain depth to power an Organic Rankine Cycle that could supply a
permanent installation, particularly at night, when solar power is not
available. Our theoretical and engineering considerations show that, with
existing working fluids and quite feasible technical requirements, it is
possible to continuously yield $25\,{\rm kW}$ to sustain a 3 member crew.
