An apparatus for heating water has a tank for storing water and an air conditioning system that defines a refrigerant flow path through which refrigerant flows. The refrigerant flow path passes through a heat exchanger so that refrigerant heat is contributed to the tank. The heat exchanger houses a phase change material. A controller controls operation of the water heating apparatus.

An equipment determination method of a cogeneration system includes the steps of: calculating a total hot water supply load for each day over a predetermined period longer than a specific period based on each unit hot water supply load for hour according to hot water supply use by consumers; setting as a representative period a specific period on which the total hot water supply load becomes at least a low load among the calculated total hot water supply load for each day; determining a capacity of the cogeneration equipment based on the total hot water supply load on the set representative period; and determining a capacity of the plurality of hot water storage tanks based on an amount of hot water supply load exceeding the capacity of the determined cogeneration equipment among each unit hot water supply load for two or more divided periods including the set representative period.

High-efficient central chiller plant system with variable load by phase change material thermal energy storage, comprising a refrigeration unit and a phase change thermal energy storage. The refrigeration unit operates under the highest COP. If the refrigerating output is higher than the demand of cooling load, the phase change thermal energy storage stores energy by the phase change. Contrarily, if the refrigerating output cannot meet the demand of cooling load, the phase change thermal energy storage releases energy to supply the insufficient cooling load of the refrigeration unit. So that users can set the operation strategy of the refrigeration unit according to the usage statistics, and let the refrigeration unit operate efficiently with the cooperation of the phase change thermal energy storage, thereby effectively improving the energy efficiency of the system operation to save energy. Compared with the existing central chiller system, it saves energy more than 40%-70%.

The invention relates to a sensible heat storage apparatus that comprises a core material that can be heated to a high temperature while it has been placed in a heat transfer fluid that absorbs essentially all the heat that is lost by any heat leakages from the core material. Accordingly, there is a very low, or almost absent overall heat loss, even though the sensible heat storage apparatus can store heat at a very high temperature. The gist of the invention is further that the high amount of heat can gradually be transferred to the HTF, which heat can in turn be put to use for domestic applications (e.g. domestic hot water and/or space heating) or for steam generation.

The invention relates to an energy storage system for storing heat and coldness and for providing electrical energy, characterized by an energy converter, wherein the energy converter is designed to produce electrical energy from heat and coldness and to produce heat and coldness from electrical energy, the energy converter being in heat-transferring contact with a hot heat exchanger and with a cold heat exchanger, the hot heat exchanger being connected to a heat reservoir and the cold heat exchanger being connected to a coldness reservoir, and a control unit being provided, which operates the energy storage system in a first operating mode, in which heat and coldness are formed from electrical energy by means of the energy converter, and in a second operating mode, in which electrical energy is produced from heat and coldness.

An instant hot water delivery system includes a thermal storage bin that receives hot water from a water heater via a hot water supply conduit and stores the hot water therein. The thermal storage bin is disposed adjacent a point of demand to deliver the hot water instantly to the point of demand responsive to a demand. The thermal storage bin is configured to retain a thermal energy of the hot water for a prolonged period using a phase change material. When the hot water stored in the thermal storage bin cools down below a threshold temperature, the cooled down hot water is recirculated to the water heater via a cold water supply conduit using a crossover valve. The recirculation is based on thermosiphon. Fresh hot water from the water heater replaces the cooled down hot water that is displaced from the thermal storage bin.

A medium for energy storage includes a plurality of capsules. Each capsule contains a phase changing material (PCM) configured to undergo a liquid-solid phase transition at a solidification temperature, T.sub.S. The PCM undergoes a relative volume change due to the phase transition. A shell is filled with the PCM. The shell contains a first heat-conducting material, and is configured to comply to the relative volume change. The relative volume change is configured to cause a buoyancy force, which acts on the capsule when the capsule is disposed in water at a water temperature, T.sub.W, to be larger than the capsule's weight for T.sub.w>T.sub.s, and equal to or smaller than the capsule's weight for T.sub.w<T.sub.s. The T.sub.s can be within ±5° F. of a design water temperature T.sub.o at the outlet of a water tank. The capsule can be neutrally buoyant in water at T.sub.o.

The present invention presents a thermochemical energy storage system. The system includes a membrane-based thermochemical reactor. The reactor includes a solution channel having an absorbent-containing solution flowing therethrough and a refrigerant channel having a refrigerant flowing therethrough along with first and second fluid channels. A porous membrane is positioned between the refrigerant channel and the solution channel; the porous membrane permits flow of vapor molecules therethrough while restricting flow of absorbent molecules. The system further includes a solution storage repository in fluid communication with the solution channel and a refrigerant repository in fluid communication with the refrigerant channel. The system can be used in high-density, high-efficiency, and low-temperature energy storage systems. The membrane-based reactor offers a large specific surface area and integrates solution/refrigerant flows, which enables formation of a highly compact reactor exhibiting strong heat/mass transfer. In some embodiments, direct diffusion of water molecules through the membrane makes it possible to lower the required charging temperatures.

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.

The present disclosure relates to particle-based thermal energy storage (TES) systems employed for the heating and cooling applications for residential and/or commercial buildings. Particle-based TES systems may store thermal energy in the particles during off-peak times (i.e., when electricity demand and/or costs are relatively low) and remove the stored thermal energy for heating or cooling applications for buildings during peak times (i.e., when electricity demand and/or costs are relatively high).