Control systems for renewable hot water heating systems

Abstract

Provided herein are systems and methods directed to using renewable energy sources with hot water heating systems. The system and method provide for interconnecting a single electrical heating element of a hot water heater to first and second electrical power sources. Typically, these first and second electrical power sources include a utility provided electrical power source (e.g., a fossil fuel AC power source) and a renewable energy power source. A controller selectively connects the first or second power sources.

1 . A method for use with a hot water heater having a first heating element connected to a fossil fuel source and a second heating element connected to a renewable energy source, comprising:
 providing a controller interconnected to the first heating element and the second heating element, wherein the controller is operative to execute logic to selectively operate the first and second element;   operating the second heating element, based on control signals from the controller, when power from a renewable energy source connected to the second heating element is available and a temperature of water in a tank of the hot water heater is below a predetermined threshold level; and   deactivation the first heating element when one of:
 electrical energy from the renewable energy source is above a predetermined level; and 
 a command is received to deactivate the first heating element from a network interface.