A convective power generation device is described based on thermal convection and thermal input energy. The energy generation device operates by heating wax and oil by heat from a solar concentrator or geothermal energy; as the weight of the wax becomes liquid that is lighter than the oil, the liquid wax moves up through a pathway; when the liquid wax reaches the top of the pathway, the cooler wax falls towards collecting cups mounted to a continuous belt and forces the belt downward to rotate the belt; when a collector cup of wax reaches the bottom of belt rotation, the wax falls to a reservoir; and the rotation of the belt drives a gearbox, which drives a generator to produce electric power. The convective power generation device has been shown to have higher energy conversion efficiency than photovoltaics.