An apparatus and method for producing heat and electricity independent of an electrical grid. The apparatus includes a burner adapted to produce at least one of radiant heat, flame and hot combustion gases. A thermal-to-electric conversion device is integrated with the burner and proximate to the burner, for producing electricity. The conversion device has a first side disposed toward the at least one of radiant heat, flame and hot combustion gases and a second side disposed toward and in heat transfer contact with a liquid supply line. The apparatus is useful in water heaters. The liquid supply line provides both water to be heated and a cooling medium for the thermal-to-electric conversion device.

A fuel cell system is disclosed. The fuel cell system includes: a fuel cell module including a plurality of unit cells for generating electrical energy by using oxygen of air and hydrogen of a reformed fuel gas; a first module including a burner part which burns an unreacted fuel gas and air discharged from the fuel cell module, an air-heating part which heats air through heat exchange with a hot combustion gas and a flame generated by the burner part and supplies the heated air to the fuel cell module, and a water vapor generation part which converts water, flowing through an inner portion thereof, into water vapor through heat exchange with a hot combustion gas generated by the burner part; and a second module which mixes a fuel supplied from an external fuel supply source and water vapor supplied from a water-vapor generator part.

The disclosed technology includes an on-demand water heater which uses an electric heat source to heat the water. The on-demand water heater can have a low fluid capacity heating chamber which has an inlet and an outlet, an electric heat source for heating the water, and a controller to control the electric heat source and maintain the temperature of the water at a predetermined temperature setting. The on-demand water heater can be powered by a direct current power source. The on-demand water heater can also utilize a solar thermal system to provide additional heat to the water.

A system for combined heat and electric power generation, preferably including a heat reservoir and one or more electric generators, each preferably including a heat source and an energy converter. A method for combined heat and electric power generation, preferably including activating an electric generator, deactivating the electric generator, and/or providing heat from a heat reservoir.

A system for combined heat and electric power generation, preferably including a heat reservoir and one or more electric generators, each preferably including a heat source and an energy converter. A method for combined heat and electric power generation, preferably including activating an electric generator, deactivating the electric generator, and/or providing heat from a heat reservoir.

Method for operating a power plant for generating energy, comprising at least one stationary internal combustion engine (1) and a district heating system (20) connected to the at least one internal combustion engine (1) in a heat exchange relationship, wherein the at least one internal combustion engine (1) is configured to deliver a mechanical power by burning a fuel, wherein on the one hand the at least one internal combustion engine (1) is cooled and on the other hand heat is supplied to the district heating system (20) through a heat exchange between the district heating system (20) and the at least one internal combustion engine (1) and wherein at least one additional cooling device (12) is provided,
wherein the cooling of the at least one internal combustion engine (1) is effected—at least partially—using the at least one additional cooling device (12) when a transient performance requirement for the at least one internal combustion engine (1) occurs.

Method for operating a power plant for generating energy, comprising at least one stationary internal combustion engine (1) and a district heating system (20) connected to the at least one internal combustion engine (1) in a heat exchange relationship, wherein the at least one internal combustion engine (1) is configured to deliver a mechanical power by burning a fuel, wherein on the one hand the at least one internal combustion engine (1) is cooled and on the other hand heat is supplied to the district heating system (20) through a heat exchange between the district heating system (20) and the at least one internal combustion engine (1) and wherein at least one additional cooling device (12) is provided,
wherein the cooling of the at least one internal combustion engine (1) is effected—at least partially—using the at least one additional cooling device (12) when a transient performance requirement for the at least one internal combustion engine (1) occurs.

A water heater control system the water heater system comprising a rechargeable and non-rechargeable power source. In one or more examples, a controller such as a microcontroller of the water heater system is configured to receive power from the non-rechargeable power source and does not receive power from the rechargeable power source. Various other components of the water heater system are configured to receive power from the rechargeable power source. The system may comprise an energy storage system electrically connected to a pilot valve operator and electrically isolated from a main valve operator. The controller may be configured to recognize a call for main burner operation and may also be configured to check an available voltage of the energy storage system against a setpoint.

A water heater control system the water heater system comprising a rechargeable and non-rechargeable power source. In one or more examples, a controller such as a microcontroller of the water heater system is configured to receive power from the non-rechargeable power source and does not receive power from the rechargeable power source. Various other components of the water heater system are configured to receive power from the rechargeable power source. The system may comprise an energy storage system electrically connected to a pilot valve operator and electrically isolated from a main valve operator. The controller may be configured to recognize a call for main burner operation and may also be configured to check an available voltage of the energy storage system against a setpoint.

There is herein described energy storage systems. More particularly, there is herein described thermal energy storage systems and use of energy storable material such as phase change material in the provision of heating and/or cooling systems in, for example, domestic dwellings.