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.

1 . (canceled) 
     
     
         2 . A hot water heating system comprising:
 a storage tank having:
 an inlet fluidly connectable to a water supply; 
 an outlet fluidly connectable to at least at least one valve, wherein when the valve is opened, water from the water supply displaces water through the storage tank and out the outlet; 
   an electrical heating element disposed within said storage tank, said electrical heating element having an electrical connector disposed outside of said storage tank;   a renewable electrical power source operative to generate electrical energy;   a junction device having:
 a first electrical connection electrically connected to said electrical connector of said electrical heating element; 
 a second electrical connection electrically connected to said renewable electrical power source; 
 a third electrical connection electrically connectable to an additional electrical power source; and 
 a switch configured to connect one of said first electrical connection to said second electrical connection and said first electrical connection to said third electrical connection, wherein, when said switch connects one of said renewable power source and said additional electrical power source to said first electrical connection the other said renewable power source and said additional electrical power source is disconnected form said first electrical connection and said renewable power source and said additional electrical power source are electrically isolated; and 
   a controller operative to actuate said switch to electrically connect said first electrical connection to one of said renewable power source and said additional electrical power source.   
     
     
         3 . The system of  claim 2 , wherein said controller is configured to connect said first and second electrical connections when an electric energy level of the renewable electrical power source is above a predetermined threshold. 
     
     
         4 . The system of  claim 3 , wherein said controller further comprises:
 a sensor configured to measure the electrical energy level of said renewable energy power source.   
     
     
         5 . The system of  claim 2 , wherein said controller is configured to connect said first and second electrical connections when a temperature of water in said storage tank is below a predetermined threshold. 
     
     
         6 . The system of  claim 5 , further comprising:
 a temperature sensor configured to measure the temperature of the water in the storage tank, wherein said temperature sensor is operatively connected to said controller.   
     
     
         7 . The system of  claim 2 , wherein said controller is configured to disconnect both of said second and third electrical connections from said first electrical connection when a temperature of water in said storage tank is above a predetermined threshold. 
     
     
         8 . The system of  claim 2 , wherein said renewable electrical power source comprises one of:
 a photovoltaic system; and   a wind turbine.   
     
     
         9 . The system of  claim 2 , wherein said controller is configured to connect said first and second electrical connections based on expected usage times of when water passes through the storage tank between the inlet and outlet. 
     
     
         10 . The system of  claim 9 , wherein the controller further comprises:
 a user interface, wherein said user interface is configured to receive said expected usage times from a system user.   
     
     
         11 . The system of  claim 2 , wherein said additional electrical power source comprises one of:
 a utility electrical power source; and   a renewable electrical power source.   
     
     
         12 . The system of  claim 2 , wherein said renewable electrical power source further comprises an inverter, wherein said renewable electrical power source provides AC electrical energy. 
     
     
         13 . A hot water heating system, comprising:
 a storage tank having:
 an inlet fluidly connectable to a water supply; 
 an outlet fluidly connectable to at least at least one valve, wherein when the valve is opened, water from the water supply displaces water through the storage tank and out the outlet; 
   a first electrical heating element disposed within said storage tank;   a renewable electrical power source operative to generate electrical energy, wherein said renewable electrical power source is selectively connectable to said first electrical heating element;   a second heating element connectable to a power source that provides one of combustible gas and electrical energy;   a sensor configured to measure an electrical energy level of said renewable energy power source; and   a controller operatively connected to said first and second heating elements, wherein said controller is operatively connected to said sensor and is operative to disable said second heating element when said electrical energy level is above a predetermined electrical threshold.   
     
     
         14 . The system of  claim 13 , further comprising:
 a temperature sensor configured to measure a temperature of water in said storage tank, wherein said temperature sensor is operatively connected to said controller.   
     
     
         15 . The system of  claim 14 , wherein said controller is further operative to disable said first heating element when the temperature of the water is above a predetermined threshold. 
     
     
         16 . The system of  claim 14 , wherein said controller is further operative to activate said second heating element when the temperature is below a predetermined threshold while said electrical energy level is above the predetermined electrical threshold, wherein said first and second heating element are simultaneously active. 
     
     
         17 . The system of  claim 13 , wherein said controller is further configured to disable said second heating element based on expected usage times of when water passes through the storage tank between the inlet and outlet. 
     
     
         18 . The system of  claim 17 , wherein the controller further comprises:
 a user interface, wherein said user interface is configured to receive said expected usage times from a system user.   
     
     
         19 . The system of  claim 17 , wherein the controller further comprises:
 operating logic configured to determine said expected usage times.