Patent ID: 8344585

Claim:
An apparatus for converting heat to electric energy, comprising: (a) a first electrode formed of a thermally and electrically conductive material; (b) a second electrode formed of a thermally and electrically conductive material, wherein the second electrode is spaced from the first electrode; (c) one or more layers of electrically polarizable material between the first and second electrodes; (d) one or more heat exchangers for removing thermal energy from or adding thermal energy to the one or more layers of electrically polarizable material; (e) a DC voltage source for applying a DC poling voltage to the one or more layers of electrically polarizable material; (f) a control circuit, the control circuit: (i) withdrawing thermal energy from the one or more layers of electrically polarizable material to cool the one or more layers of electrically polarizable material to a temperature T L using the one or more heat exchangers, wherein current does not flow between the first and second electrodes during cooling; (ii) subsequently applying the DC poling voltage to the one or more layers of electrically polarizable material; (iii) withdrawing thermal energy from the one or more layers of electrically polarizable material using the one or more heat exchangers while the DC poling voltage is applied to the one or more layers of electrically polarizable material and current is allowed to flow between the first and second electrodes such that the electrically polarizable material develops an overall net spontaneous polarization and screening charges are generated on the first and second electrodes; (iv) removing the DC poling voltage from the one or more layers of electrically polarizable material; (v) subsequently adding thermal energy to the one or more layers of electrically polarizable material to heat the electrically polarizable material to a temperature T H using the one or more heat exchangers while not allowing current to flow between the electrodes, wherein the DC poling voltage is not applied to the one or more layers of electrically polarizable material while thermal energy is added to the electrically polarizable material; (vi) subsequently connecting the first and second electrodes across a load; and (vii) subsequently adding thermal energy to the one or more layers of electrically polarizable material while the electrodes are connected across the load such that electrical energy corresponding to the generated screening charges on the pair of electrodes is output to the load; wherein the electrically polarizable material exhibits spontaneous polarization at T L and wherein the spontaneous polarization exhibited by the electrically polarizable material at T H is less than the spontaneous polarization exhibited by the electrically polarizable material at T L .