A heat storage and transfer system incorporates a primary heat storage chamber that is thermally insulated and which in use, contains a heat storing liquid or solid and a thermal energy to electrical energy converter in or thermally coupled to at least one of: i) a secondary chamber external to and adjacent the primary heat storage chamber through which a liquid or steam to be heated is passed in use; and ii) a thermal conduction plate/surface external to the thermally insulated primary heat storage chamber or body. The system has a heat transfer feature to selectively transfer thermal energy from the heat storing liquid or solid of the primary heating chamber to the thermal conduction plate or the liquid or steam to be heated in the secondary chamber for the thermal energy to thence be converted to electrical energy by the thermal energy to electrical energy converter.