Electrical water heater with a dual resistive heating element and a control method for energy management

摘要

An electrical water heater adapted for energy management and a method of controlling the consumption of electrical power from the power supply grid of a utility is described. The bottom resistive heating element of the water heater is a dual element resistive heating element which has a high power rated resistive heating element to heat water and a further low power rated resistive heating element. The power rating of the low power resistive heating element is calculated to be lower than the supply grid diversified mean load. A controller has a communication link with a utility which manages the power supply grid. The utility can control the resistive heating elements of the dual element in such a way, and depending on conditions of the grid, to conserve energy and regulate its frequency thereby resulting in a cost saving to the consumer and the utility. The low power rated resistive heating element is also connectable to an alternative power source.

主权项

1. A three element electrical water heater for energy management, said water heater having a water storage tank, a first resistive heating element secured in a top portion of said tank, a second resistive heating element secured in a mid-portion of said tank, a third resistive heating element secured in a bottom portion of said tank, each said resistive heating elements having a power rating to heat water in their respective portions of said tank, a thermostatic control associated with each said resistive heating elements, a power source connected to said thermostatic controls for supplying current to said resistive heating elements, a fourth resistive heating element in said bottom portion of said tank and having a power rating much lower than said first, second and third resistive heating elements, a controller for selectively operating said third and fourth resistive heating elements, a communication link between said controller and a utility managing a power supply grid from which said power source originates, said utility providing command signals to said controller through said communication link to enable selected ones of said third and fourth resistive heating elements based on grid load conditions.