An energy recovery system (10) including a structure (12) including at least a boundary (14) area made of a material which is substantially transparent to solar radiation, thus to capture solar energy in the internal environment of the structure, a heat pump (19) including a closed fluid circuit (16) which includes a first heat exchanger (18) in which heat from the internal environment of the structure (12) is transferred to the fluid, a second heat exchanger (20) in which heat from the fluid is transferred to a heat energy store (24), and an impeller (22) for moving the fluid from the first heat exchanger (18) where the fluid is at a generally lower pressure to the second heat exchanger (20) where the fluid is at a generally higher pressure, power to drive the impeller (22) being derived solely from the energy stored.
