The disclosed technology relates to a solar water heating system including a tank configured to store heat transfer fluid, a solar collector in fluid communication with the tank, and a pump system in fluid communication with the tank and the solar collector. The pump system can include a first pump, a second pump, and a valve assembly. The valve assembly can direct the heat transfer fluid from an outlet of the first pump to the solar collector when the first pump is operating and can direct the heat transfer fluid from an outlet of the second pump to the solar collector when the second pump is operating. The first pump and the second pump can transfer the heat transfer fluid from the solar collector back to the tank when the first pump and the second pump are not operating.

The present disclosure provides a water heating system for efficient heating of water for immediate use that fits either to industrial applications or household applications. The water heating system is suitable to be combined with a solar heating unit and it can be operated on electric power or on gas-based heating units for providing hot water to multiple consumers for household or industrial utilization. Furthermore, the system can be stand-alone, operating without any additional water heating system and can provide an immediate stream of hot water, e.g. it can be installed within a water supplying appliance. The water can operate in two modes: (1) heating for immediate use of hot water; and (2) heating water to be contained in a reservoir for later use. The system uses a two (bi) directional flow valve.

A control system suitable for use with a bathing unit system having a water receptacle is provided. The control system comprises first and second heating modules and a controller configured for activating a specific one of the first and second heating module at least in part based on whether the bathing unit is in use.

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.

This invention provides a system and process to optimize photovoltaic (PV), grid, and other electricity in powering an electric water heater. The system comprises a photovoltaic (PV) controller coupled to a plurality of power input sources and heating elements wherein the heating elements immersed in an electric immersion heater water tank. The PV controller is further configured with control circuitry having an operating efficiency routine calculating optimal use cases from a variety of installation parameters and learned parameters to determine the appropriate power input source and switch between sources accordingly.

A solar photovoltaic (PV) water heating system includes a tank including at least a first heating unit having at least first and second heating elements, at least one of which is switchable; a PV solar collector; an inverter adapted to convert the output from the PV collector to an alternating power supply; a modulator to modulate the alternating power supply from the inverter; a controller adapted to control the modulator and the switching of the or each switchable heating element; wherein the controller is adapted to control the modulator and the switchable heating elements to maximize the energy drawn from the PV collector.

A solar photovoltaic (PV) water heating system includes a tank (1.020) including at least a first heating unit (1.016) having at least first and second heating elements (1.016.1 . . . 1.016.x), at least one of which is switchable (1.014.1A . . . 1.014.1m); a PV solar collector (1.002); an inverter (1.004) adapted to convert the output from the PV collector to an alternating power supply; a modulator (1.060) to modulate the alternating power supply from the inverter; a controller (1.040) adapted to control the modulator and the switching of the or each switchable heating element; wherein the controller is adapted to control the modulator and the switchable heating elements to maximize the energy drawn from the PC collector.

A solar photovoltaic (PV) water heating system includes a tank (1.020) including at least a first heating unit (1.016) having at least first and second heating elements (1.016.1 . . . 1.016.x), at least one of which is switchable (1.014.1A . . . 1.014.1m); a PV solar collector (1.002); an inverter (1.004) adapted to convert the output from the PV collector to an alternating power supply; a modulator (1.060) to modulate the alternating power supply from the inverter; a controller (1.040) adapted to control the modulator and the switching of the or each switchable heating element; wherein the controller is adapted to control the modulator and the switchable heating elements to maximize the energy drawn from the PC collector.

A solar photovoltaic (PV) water heating system includes a tank including at least a first heating unit having at least first and second heating elements, at least one of which is switchable; a PV solar collector; an inverter adapted to convert the output from the PV collector to an alternating power supply; a modulator to modulate the alternating power supply from the inverter; a controller adapted to control the modulator and the switching of the or each switchable heating element; wherein the controller is adapted to control the modulator and the switchable heating elements to maximize the energy drawn from the PV collector.

A system of capturing waste heat includes a heat recovery unit (20) having a heat exchanger (35) arranged to transfer heat between a fluid circulating in a refrigerant loop (60) and a fluid circulating in a solar loop (70) and another heat exchanger (39) arranged to transfer heat between the fluid in the solar loop (70) and a fluid circulating in a water loop (50). Controllable first, second, and third three-way valves (V1-V3) provide or prevent, depending on fluid temperatures, an A-B, B-C, and A-C flow path through the valve. The first valve (V1) is arranged in the water loop (50) upstream of the second heat exchanger (39). The second (V2) is arranged in the solar loop (70) upstream of the second heat exchanger (39). The third valve (V3) is arranged in the solar loop (70) between the first and second heat exchangers (35, 39).