Systems and methods for a thermosyphonic water heating system for a storage tank. A DC heat pump receives power from a DC power source and heats water via a heat exchanger using a thermosyphonic piping system. A passive back-flushing having a cold water inlet pipe connected to the hot water return pipe draws cold water into the storage tank through the heat exchanger. A vertical array of temperature sensors distributed throughout the storage tank monitor temperature of stored water at multiple heights and a communication unit communicates monitored data to an external control device.

Provided is a fuel cell system. The fuel cell system comprises: a reformer that reforms fuel; a reformed fuel storage unit that receives the reformed fuel from the reformer and stores same; a fuel cell stack that generates electric power and heat by using the reformed fuel; a boiler unit that provides heating by using heating water, a battery unit that stores the electric power generated in the fuel cell stack; and a control unit that controls the operations of the reformer, the reformed fuel storage unit, the fuel cell stack, the boiler unit, and the battery unit, wherein the control unit controls the reformer to operate using the heating water of the boiler unit when the temperature of the heating water of the boiler unit is higher than a first baseline and the stored amount of the reformed fuel stored in the reformed fuel storage unit is equal to or less than a second baseline.

A liquid heating appliance for heating water or other liquids, suitably to a target temperature of from 55° C. to around boiling point, includes a primary heat chamber or body (heat source chamber) that is thermally insulated and which in use contains a high thermal density heat storing liquid or solid; and a secondary chamber alongside the primary chamber through which a liquid to be heated is passed in use. The appliance has a heat transfer feature to selectively transfer thermal energy from the heat-storing liquid or solid to the liquid to be heated in the secondary chamber. The secondary chamber is preferably a conduit through which the liquid to be heated is able to flow and the thus heated liquid can be delivered to a tap as hot water for a range of uses. Water may also be heated for a central heating system for space heating.

A boiler unit comprises an enclosure including: a first circuit of a first fluid heat exchange medium, the first circuit having a heating device to heat the first medium, a boost heat exchanger, a valve and a first manifold; a second circuit of a second heating system fluid heat exchange medium, the second circuit having a flow and return port of the boiler unit, a second manifold and said boost heat exchanger for exchange of heat between said first and second heat exchanger media when said valve is open; a space in the enclosure receiving an auxiliary unit to be driven substantially exclusively by said first fluid heat exchange medium; and a boiler control unit to control operation of the heating device according to heat demand of the heating device and otherwise irrespective of the auxiliary unit when connected; and an organic rankine cycle (ORC) unit comprising: a third fluid heat exchange medium circuit, the circuit including a condenser adapted for connection to said second manifold to provide heat to said second circuit, a pump to circulate said third medium, an evaporator adapted for connection to said first manifold to heat said third medium and a rotary expander connected to an electricity generator; and an auxiliary control unit to control the ORC unit and operate said valve.

Synergistic Energy Ecosystem using a co-generation system and method wherein waste energy from waste heat producers within an enclosure including an electric generator is reclaimed to supply heat to the cold end of a heat pump within the enclosure for optimized use in space heating a habitat and to the management of the distribution of electricity from the generator so as to supply electricity to the habitat and to neighbouring habitats when efficient, cost-effective or required to do so by distribution policies managing the energy eco-system.

A distributed solar power generation and hot water supplying system includes: a photovoltaic power generation self-service sun tracking system, an inverter, a controller, a storage battery, a heat-exchanging water tank and an electric heater provided therein, wherein a solar battery and a solar collector are mounted on the photovoltaic power generation self-service sun tracking system, an electricity output terminal of the photovoltaic power generation self-service sun tracking system is respectively connected to an inversing input terminal of an inverter and a surplus power supplying input terminal of a controller; an MCU-controlled power output terminal of the inverter is respectively connected for off-grid power consumption or grid-connected power generation, and to an inversing output terminal of the controller; a charging/discharging control output/input terminal inside the inverter is connected to an input/output terminal of the storage battery and a storage battery power supplying input terminal of the controller.

A combined heat, cooling and power system is configured to generate energy as well capture a large percentage of energy that would otherwise be lost using components, including heat transfer components, embedded within a vessel to transfer energy in the form of heat to liquid within the vessel.

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 hot-water supply system heats up water by power generated by power generation means. The hot water supply system includes a compressor and a water heat-up unit. In the hot-water supply system, the compressor compresses refrigerant and circulates the refrigerant through a refrigerant circuit. The water heat-up unit heats up water by changing, in accordance with the generated power, a rotation rate of an electric motor for driving the compressor.

A combined heating and power system is configured to generate energy as well capture a large percentage of energy that would otherwise be lost using components, including heat transfer components, embedded within a vessel to transfer energy in the form of heat to liquid within the vessel.