Self sustaining energy system for a building

Abstract

A self sustaining energy system for a building is provided part of which is typically driven by geothermal energy. The energy system typically uses a ground source heat pump for heating and cooling the building airspace and an organic Rankine cycle drive for producing electricity. A solar powered heating system may also serve as a heat source for providing domestic hot water and supplemental airspace heating.

1 . An energy system comprising:
 a heat pump comprising a first earth-coupled heat exchanger;   an electric motor operatively connected to the heat pump;   an organic Rankine cycle drive;   a second earth-coupled heat exchanger which provides a geothermal heat source for the organic Rankine cycle drive; and   an electric generator driven by the organic Rankine cycle drive and in electrical communication with the motor.   
     
     
         2 . The energy system of  claim 1  further comprising a building defining an airspace; an air intake of the heat pump in fluid communication with the airspace; and an air exhaust of the heat pump in fluid communication with the airspace. 
     
     
         3 . The energy system of  claim 1  further comprising a compressor of the heat pump; wherein the electric motor is operatively connected to the compressor. 
     
     
         4 . The energy system of  claim 1  wherein the organic Rankine cycle drive comprises a third earth-coupled heat exchanger configured to reject heat to the ground. 
     
     
         5 . The energy system of  claim 1  further comprising a third earth-coupled heat exchanger configured to release heat energy to the ground to prevent the ground from freezing as a result of the heat energy absorbed from the ground by at least one of the first and second earth-coupled heat exchangers. 
     
     
         6 . The energy system of  claim 5  further comprising a solar powered heating system coupled to the third earth-coupled heat exchanger whereby the solar powered heating system is configured to reject heat to the third earth-coupled heat exchanger. 
     
     
         7 . The energy system of  claim 6  further comprising a domestic hot water system coupled to the solar powered heating system whereby the solar powered heating system is configured to reject heat to water in the domestic hot water system. 
     
     
         8 . The energy system of  claim 7  further comprising a thermal storage tank; a phase change material within the tank; and a portion of the domestic hot water system which extends adjacent the tank whereby the water within the domestic hot water system is configured to reject heat to and melt the phase change material. 
     
     
         9 . The energy system of  claim 5  further comprising a thermal storage tank; a phase change material within the tank; a recirculation loop in fluid communication with the third earth-coupled heat exchanger; a fluid within the recirculation loop; and a portion of the recirculation loop which extends adjacent the tank whereby the fluid within the recirculation loop is configured to reject heat to and melt the phase change material. 
     
     
         10 . The energy system of  claim 5  wherein the organic Rankine cycle drive comprises a fourth earth-coupled heat exchanger configured to release heat energy to the ground. 
     
     
         11 . The energy system of  claim 1  further comprising a domestic hot water system comprising an underground pipe configured to release heat energy to the ground to prevent the ground from freezing as a result of the heat energy absorbed from the ground by at least one of the first and second earth-coupled heat exchangers. 
     
     
         12 . The energy system of  claim 11  further comprising a solar powered heating system coupled to the domestic hot water system whereby the solar powered heating system is configured to reject heat to the domestic hot water system. 
     
     
         13 . The energy system of  claim 1  wherein the second earth-coupled heat exchanger extends into an aquifer. 
     
     
         14 . The energy system of  claim 1  wherein the second earth-coupled heat exchanger extends into the ground to a depth of at least 500 feet. 
     
     
         15 . The energy system of  claim 1  further comprising a first borehole formed in earth beneath a building; wherein one of the first and second earth-coupled heat exchangers is within the first borehole. 
     
     
         16 . The energy system of  claim 1  wherein the organic Rankine cycle drive comprises a third earth-coupled heat exchanger configured to release heat energy to the ground. 
     
     
         17 . A method comprising the steps of:
 operating an electric motor to circulate a working fluid in a heat pump which comprises a first earth-coupled heat exchanger;   providing a geothermal heat source for an organic Rankine cycle drive with a second earth-coupled heat exchanger;   driving an electric generator with the organic Rankine cycle drive to produce electricity; and   using the electricity to power operation of the electric motor.   
     
     
         18 . The method of  claim 17  further comprising cooling a portion of the ground by releasing heat from the portion of the ground to at least one of the first and second earth-coupled heat exchangers; heating a third earth-coupled heat exchanger with a solar powered heating system; and rejecting heat from the third earth-coupled heat exchanger to the cooled portion of the ground. 
     
     
         19 . The method of  claim 17  further comprising rejecting heat from the organic Rankine cycle drive to the ground with a third earth-coupled heat exchanger. 
     
     
         20 . An energy system comprising:
 a first earth-coupled heat exchanger configured to absorb heat energy from soil; and   a second earth-coupled heat exchanger configured to release heat energy to the soil to prevent the soil from freezing as a result of the heat energy absorbed by the first heat exchanger.