An adaptor for adapting a solar electric generator and solar heater to a thermal storage device, the adaptor including a first port, a second port, a third port, a fourth port and a pump configured for receiving a fluid through the third port and pulling the fluid through the third port from a thermal storage device to the fourth port, wherein the first port and the fourth port are configured to be supplied on a first surface and the second port and third port are configured to be supplied on a second surface.

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 dual energy gas water heater is described and wherein a square flange, curved resistor style resistive heating element, is secured in a bottom portion of the tank of the water heater spaced above a top wall of the combustion chamber. A gas burner is secured in the combustion chamber and connected to a gas supply line through a gas valve. The curved resistive heating element is a low density, long life, element having a density in the range of about 20 to 80 watts/sq. inches. A switch is secured between the thermostat of the resistive heating element and the voltage supply line. A controller selectively operates the switch and the gas valve to disconnect the voltage supply line from the thermostat and/or shut-off the gas valve secured to the gas supply line depending on the desired source of energy. The controller is adapted to be optionally controlled by a utility/provider through a communication link. Renewable energy source may also be secured to an additional resistive heating element to improve the efficiency thereof.

A storage water heater includes at least one heating device, at least one storage tank wherein water is stored and heated, at least one control and management unit capable of checking at least the heating device, at least one inlet duct through which water may be introduced into the tank, at least one outlet duct through which water may be sent/withdrawn from the tank, wherein there are at least two heating devices, of which at least one main heating device and at least one auxiliary heating device are provided, and wherein the water heater includes a circulator dedicated, via at least one hydraulic connection duct, to the recirculation of the storage water stored in the tank, the circulator being capable of recirculating the water of the storage between the lower part and the top part of the tank, by passing through the auxiliary heating device.

A storage water heater includes at least one heating device, at least one storage tank wherein water is stored and heated, at least one control and management unit capable of controlling the at least one heating device, at least one inlet duct through which water may be introduced into the tank, at least one outlet duct through which water may be sent/withdrawn from the tank, at least two heating devices, of which at least one main heating device and at least one second auxiliary heating device adapted to act as a pre-heater, wherein the water heater includes a by-pass duct capable of deviating, entirely or partially, the water flow entering the tank so as to guide and convey it in a zone of the tank placed at a height higher than the outlet section of the inlet duct.

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 system for solar assisted water heating provides hot water to a user at a lower cost, higher energy efficiency, and with a quicker response time than conventional systems, reducing energy losses, and improving user comfort. The basic architecture includes four main components: a solar collector, a heat exchanger, an in-line heater, and a control system. A transient heat profile of a first temperature in a primary loop is measured while a first flow generator G1 is active for the primary loop. Solar assisted heating of water in a secondary loop is provided based on: a flow of water in the secondary loop; a current first temperature; and the transient heat profile of the first temperature by activating: the first flow generator in the primary loop and an in-line water heater in the secondary loop.

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.

Provided is a method of disinfecting a hot water supply system having a plurality of controllable hot-water outlets and a water heating arrangement including an energy store comprising a phase change material that has a phase transition temperature of less than 60 Celsius, the method comprising: informing an operator of a future disinfection event; increasing a hot water supply temperature from a pre-event temperature of less than 60 Celsius to a disinfection temperature; providing a signal to the operator to cause the operator to open a first of the hot water outlets; providing a signal to the operator to close the first outlet after a disinfection period; providing a signal to the operator to open another hot water outlet; providing a signal to the operator to close the another hot water outlet after a disinfection period; and repeating the signalling to the operator to open and then, after a disinfection period, to close each of the plurality of controllable hot-water outlets; reducing the hot water supply temperature to the pre-event temperature of less than 60 Celsius from the disinfection temperature; and indicating to the operator the completion of the disinfection event. A corresponding hot water supply system is also provided, the system preferably including a heat pump.

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.