Patent ID: 8707693

Claim:
A method of harvesting energy comprising: driving a plurality of heat engines to convert thermal energy to mechanical energy, wherein driving the plurality of heat engines includes: exposing localized regions of a continuous loop of a shape memory alloy for each of the plurality of heat engines to heat exchange contact with a first region and a second region having a temperature difference therebetween, wherein the continuous loop of the shape memory alloy for each of the plurality of heat engines has a crystallographic phase changeable between austenite and martensite in response to the temperature difference between the first region and the second region, wherein exposing the localized regions of the continuous loop of the shape memory alloy for each of the plurality of heat engines to heat exchange contact with the first region and the second region further comprises adjusting a barrier operatively connected to a first of the plurality of heat engines to thereby adjust the temperature difference between the first region and the second region for a successive one of the plurality of heat engines; expanding and contracting the localized regions of the continuous loop of the shape memory alloy in response to the temperature difference between the first region and the second region; and rotating the continuous loop of the shape memory alloy in response to expanding and contracting the localized regions of the continuous loop of the shape memory alloy; rotating at least one pulley with the continuous loop of each of the plurality of heat engines; and driving a component with the rotation of the at least one pulley.