A method for converting heat to electric energy, comprising: thermally cycling an electrically polarizable material (110, 210, 510, 810, FE 1...FE n), if desired an electrically polarizable amorphous polymer material, between a first temperature T 1 and a second temperature T 2 by alternately adding thermal energy to and withdrawing thermal energy from the electrically polarizable material, wherein the electrically polarizable material is positioned between first and second electrodes (122, 522, 622, 822; 124, 524, 624, 824; 1320...1329) each formed of a thermally and electrically conductive material, wherein the electrically polarizable material exhibits spontaneous polarization at T 1 and wherein the spontaneous polarization exhibited by the electrically polarizable material at T 2 is less than the spontaneous polarization exhibited by the electrically polarizable material at T 1; wherein a DC poling voltage is applied to the electrically polarizable material when the electrically polarizable material is in a first portion of the cycle which includes the temperature T 1, to develop an overall net spontaneous polarization so as to generate screening charges on the first and second electrodes, and the DC poling voltage is not applied to the electrically polarizable material when the electrically polarizable material is in a second portion of the initial cycle which includes the temperature T 2; wherein the first and second electrodes are connected to a load (R L) such that electrical energy is output from the first and second electrodes to the load when the electrically polarizable material is in the second portion of the cycle which includes the temperature T 2 at which the DC poling voltage is not applied to the electrically polarizable material; wherein residual charges are left on the first and second electrodes after the electrical energy is output to the load and characterised in that the residual charges provide the DC poling voltage for the next cycle such that in the next cycle, no external DC poling voltage is applied to the electrically polarizable material; and wherein the electrical energy output from the first and second electrodes to the load preferably is rectified. thermally cycling an electrically polarizable material (110, 210, 510, 810, FE 1...FE n), if desired an electrically polarizable amorphous polymer material, between a first temperature T 1 and a second temperature T 2 by alternately adding thermal energy to and withdrawing thermal energy from the electrically polarizable material, wherein the electrically polarizable material is positioned between first and second electrodes (122, 522, 622, 822; 124, 524, 624, 824; 1320...1329) each formed of a thermally and electrically conductive material, wherein the electrically polarizable material exhibits spontaneous polarization at T 1 and wherein the spontaneous polarization exhibited by the electrically polarizable material at T 2 is less than the spontaneous polarization exhibited by the electrically polarizable material at T 1; wherein a DC poling voltage is applied to the electrically polarizable material when the electrically polarizable material is in a first portion of the cycle which includes the temperature T 1, to develop an overall net spontaneous polarization so as to generate screening charges on the first and second electrodes, and the DC poling voltage is not applied to the electrically polarizable material when the electrically polarizable material is in a second portion of the initial cycle which includes the temperature T 2; wherein the first and second electrodes are connected to a load (R L) such that electrical energy is output from the first and second electrodes to the load when the electrically polarizable material is in the second portion of the cycle which includes the temperature T 2 at which the DC poling voltage is not applied to the electrically polarizable material; wherein residual charges are left on the first and second electrodes after the electrical energy is output to the load and characterised in that the residual charges provide the DC poling voltage for the next cycle such that in the next cycle, no external DC poling voltage is applied to the electrically polarizable material; and wherein the electrical energy output from the first and second electrodes to the load preferably is rectified.