District GeoExchange Systems                                                                                Green Building...
District GeoExchange Systems    The earth is a heat source in winterThe temperature of the earth a few meters below the su...
District GeoExchange Systems    A heat sink in summerIn summer, even though the air temperature may be 30C, the temperatu...
District GeoExchange Systems    A ground heat exchanger transfers energy to and from the groundTo move heat to the ground ...
District GeoExchange Systems    Typical geothermal systemsGeothermal systems are typically designed and built for individu...
District GeoExchange Systems    Different methods of building a GHXA GHX can be buried in a horizontal trench or excavatio...
District GeoExchange Systems   District GeoExchange systems in citiesSmall urban building lots prevent many homeowners fro...
District GeoExchange Systems    District GHX for homes and buildings on small propertiesUrban areas often have land areas ...
District GeoExchange Systems    The district GeoExchange system approachThere are about 360 homes in the blocks immediatel...
District GeoExchange Systems    Thinking about energy use while planning a developmentA single ice arena must get rid of 1...
District GeoExchange Systems    Synergies between buildingsDifferent buildings operate differently. Single family homes in...
District GeoExchange Systems    Ambient temperature district geothermal energy system – Gibsons, BCA new housing developme...
District GeoExchange Systems     Looking at the big picture for energyAs the development grows additional commercial space...
District GeoExchange Systems     Connecting to other energy sources / sinksThe storm sewer servicing the development is be...
District GeoExchange Systems      Lot size is limitation for horizontal GHX configuration in GibsonsMany of the building l...
District GeoExchange Systems    Aquifer is limitation for vertical GHX in GibsonsThe Town of Gibsons draws it’s drinking w...
District GeoExchange Systems    Phase oneThe first phase of the development plan includes approximately 133 single familyh...
District GeoExchange Systems    Simplified system schematicGHX modules connect to a header in a central pump house. Fluid ...
District GeoExchange Systems   Pump houseThe pump house connects the distribution lines to the GHX modules. The first thre...
District GeoExchange Systems    Typical home heat pump installationHome owner connects to curb stop valves at the property...
District GeoExchange Systems    Individual homeowner’s installation cost comparisonThe cost of installing the heat pump in...
District GeoExchange Systems    Benefits to the homeownerMonthly energy cost to the homeowner is approximately 35% less th...
District GeoExchange Systems   Responsibility for constructionComponents of the system are the responsibility of different...
District GeoExchange Systems   Responsibility for construction cost • Town installs, owns and operates the GHX and pump ho...
District GeoExchange Systems    Incentives provide start up capitalTo enable this project to move ahead the Town was able ...
District GeoExchange Systems    Economics – Town of Gibsons return on investmentThe Town of Gibsons will be invoicing cust...
District GeoExchange Systems    Optimization of building & GHX is needed to make the economics workA GeoExchange system ca...
District GeoExchange Systems      Finding room for another utilityStreets in new developments are filled with utilities. M...
District GeoExchange Systems    Future expansion of systemAs the development expands additional buildings are easily added...
District GeoExchange Systems  Why district geothermal systems and why Gibsons would want one• Environment: BC mandates tha...
District GeoExchange Systems    Future energy sources – data centersCooling data centers is costly…Waste energy from a dat...
District GeoExchange Systems    Future energy sources - wasteTechnologies are available that convert waste into heat and e...
District GeoExchange Systems    Making full use of systems provides greater benefitsThe Enwave deep water cooling system, ...
District GeoExchange SystemsQuestions or comment?                                                                         ...
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District GeoExchange Systems

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by Ed Lohrenz
District GeoExchange Systems case study (Gibsons, B.C.) including cost benefit analysis and return on investment

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District GeoExchange Systems

  1. 1. District GeoExchange Systems Green Building Festival 2012-10-12 District GeoExchange Systems Ed Lohrenz, B.E.S., CGD 1503 – 220 Portage Avenue Winnipeg, Manitoba 204-255-5959 ed@geoxergy.com Green Building Festival – Evergreen Brick Works, Toronto, ON – October 11 & 12, 2012 Slide 1
  2. 2. District GeoExchange Systems The earth is a heat source in winterThe temperature of the earth a few meters below the surface is very constant. Insouthern Ontario, the temperature of the earth in winter is about 10C even though theair temperature may be -25C.It’s a good heat source for a heat pump. Green Building Festival – Evergreen Brick Works, Toronto, ON – October 11 & 12, 2012 Slide 2
  3. 3. District GeoExchange Systems A heat sink in summerIn summer, even though the air temperature may be 30C, the temperature of the earthis still 10C.It’s a good place to get rid of heat removed from a building…much more efficiently thantrying to reject heat to an air cooled condenser. Green Building Festival – Evergreen Brick Works, Toronto, ON – October 11 & 12, 2012 Slide 3
  4. 4. District GeoExchange Systems A ground heat exchanger transfers energy to and from the groundTo move heat to the ground from a building, or extract heat from the ground, all weneed is a ground heat exchanger (GHX)It’s simply plastic pipe buried in the ground under or around a building. Green Building Festival – Evergreen Brick Works, Toronto, ON – October 11 & 12, 2012 Slide 4
  5. 5. District GeoExchange Systems Typical geothermal systemsGeothermal systems are typically designed and built for individual buildings… onebuilding, one GHX. This can be limiting in urban areas because small properties limitthe size of the GHX and make it more challenging to build.In larger commercial properties the GHX is often built under the footprint of the building. Green Building Festival – Evergreen Brick Works, Toronto, ON – October 11 & 12, 2012 Slide
  6. 6. District GeoExchange Systems Different methods of building a GHXA GHX can be buried in a horizontal trench or excavation, inserted in a deep borehole,or laid into a body of water. Green Building Festival – Evergreen Brick Works, Toronto, ON – October 11 & 12, 2012 Slide 6
  7. 7. District GeoExchange Systems District GeoExchange systems in citiesSmall urban building lots prevent many homeowners from taking advantage ofrenewable energy from the earth on their own property. http://maps.google.ca/maps/mm?q=housing+development&hl=en&gbv=2&ie=UTF8&ll=43.744918,-79.755374&spn=0.000439,0.0012&t=h&z=20 Green Building Festival – Evergreen Brick Works, Toronto, ON – October 11 & 12, 2012 Slide 7
  8. 8. District GeoExchange Systems District GHX for homes and buildings on small propertiesUrban areas often have land areas that can be used to install a GHX including schoolyards, parks and greenbelt areas.This approach requires cooperation between the city, school board and the developer. The area shown on the previous slide is adjacent to large areas of land that can easily accommodate the GHX needed for the homes shown. 27,000 m2 35,000 m2 Green Building Festival – Evergreen Brick Works, Toronto, ON – October 11 & 12, 2012 Slide 8
  9. 9. District GeoExchange Systems The district GeoExchange system approachThere are about 360 homes in the blocks immediately surrounding 62,000 m2 of land(6.5 ha) that can provide the energy needed for these homes.The school, about 4,000 m2 in area, could also benefit from the free, renewable energyavailable from the land. 20 46 23 36 40 27,000 m2 43 52 24 35,000 m2 40 18 42 Green Building Festival – Evergreen Brick Works, Toronto, ON – October 11 & 12, 2012 Slide 9
  10. 10. District GeoExchange Systems Thinking about energy use while planning a developmentA single ice arena must get rid of 1,500,000 to 2,000,000 kWh of energy per year. Ahome withdraws 10-20,000 kWh of energy from a GHX.Synergies between different types of buildings benefit by reducing the size and cost ofthe GHX needed. Understanding energy profiles of buildings and taking advantage ofthem may influence city planning. 20 A single ice arena has to get rid of enough 46 23 energy to heat 75 to 150 homes. 36 40 27,000 m2 43 52 School 24 Ice arena 35,000 m2 40 18 42 Green Building Festival – Evergreen Brick Works, Toronto, ON – October 11 & 12, 2012 Slide 10
  11. 11. District GeoExchange Systems Synergies between buildingsDifferent buildings operate differently. Single family homes in the cold Canadian climatetend to require much more heating than cooling. Large office buildings, stores, schools,multi-family residential and industrial buildings tend to require cooling even in winter.If different types of buildings are connected to the same GHX, it can be much smaller. Green Building Festival – Evergreen Brick Works, Toronto, ON – October 11 & 12, 2012 Slide 11
  12. 12. District GeoExchange Systems Ambient temperature district geothermal energy system – Gibsons, BCA new housing development is being built in the Town of Gibsons, BC, near Vancouver.The community wished to minimize green house gas emissions as much as possibleand wanted to promote the use of geothermal systems.Gibsons Vancouver Green Building Festival – Evergreen Brick Works, Toronto, ON – October 11 & 12, 2012 Slide 12
  13. 13. District GeoExchange Systems Looking at the big picture for energyAs the development grows additional commercial space added to the GHX will helpbalance the heating and cooling loads to the GHX. Heat rejected from coolingcommercial buildings will replace heat extracted by the heating dominant homes.Taking advantage of these synergies reduces the size and cost of the GHX needed fora district GeoExchange system. Future phases Phase 1 Future phasesCommercial Hockey rink &development commercial development Ocean Green Building Festival – Evergreen Brick Works, Toronto, ON – October 11 & 12, 2012 Slide 13
  14. 14. District GeoExchange Systems Connecting to other energy sources / sinksThe storm sewer servicing the development is being rebuilt in the near future. Aconnection to the ocean water can be installed at the same time. The moderatetemperature of the ocean will be used to ensure the temperature of the GHX can bemaintained at efficient operating temperatures. Future phases Phase 1 Future phasesCommercial Hockey rink &development commercial development Ocean Ocean – connection 10-12 C year round Green Building Festival – Evergreen Brick Works, Toronto, ON – October 11 & 12, 2012 Slide 14
  15. 15. District GeoExchange Systems Lot size is limitation for horizontal GHX configuration in GibsonsMany of the building lots are fairly small...some as small as 49’ x 92’. Horizontal GHXconfigurations were not possible...only realistic option was vertical configuration. 13272 80 13266 13266 132 Green Building Festival – Evergreen Brick Works, Toronto, ON – October 11 & 12, 2012 Slide 15
  16. 16. District GeoExchange Systems Aquifer is limitation for vertical GHX in GibsonsThe Town of Gibsons draws it’s drinking water from an aquifer directly beneath theproposed development. The Town was hesitant to allow drilling into the aquifer, or evenpenetrate the 70’ to 90’ silt and clay overburden overlying the sand & gravel aquiferbecause of perceived danger to their drinking water supply. Upper Gibsons development Gibsons drinking water aquifer Green Building Festival – Evergreen Brick Works, Toronto, ON – October 11 & 12, 2012 Slide 16
  17. 17. District GeoExchange Systems Phase oneThe first phase of the development plan includes approximately 133 single familyhomes, duplexes and cluster homes.Green belt and park areas owned by the Town can be used for construction of a GHX. Park & greenbelt areas Homes under construction Phase 1 Phase 2 Green Building Festival – Evergreen Brick Works, Toronto, ON – October 11 & 12, 2012 Slide 17
  18. 18. District GeoExchange Systems Simplified system schematicGHX modules connect to a header in a central pump house. Fluid is circulated throughthe GHX modules by individual pumps in the pump house.Supply and return distribution lines are installed along the street by the developer muchlike water and sewer lines, with shutoff valves at the property lines of each home.The home builder connects the heat pump & pump to the distribution lines. Green Building Festival – Evergreen Brick Works, Toronto, ON – October 11 & 12, 2012 Slide 18
  19. 19. District GeoExchange Systems Pump houseThe pump house connects the distribution lines to the GHX modules. The first threeGHX modules are connected and will serve up to 35-40 homes. An additional 11 GHXmodules can be connected and will serve approximately 250 to 300 homes.Connections to a second pump house and a commercial development will provide loaddiversity and facilitate energy transfer between buildings. Future GHX module connections Distribution lines to homes Green Building Festival – Evergreen Brick Works, Toronto, ON – October 11 & 12, 2012 Slide 19
  20. 20. District GeoExchange Systems Typical home heat pump installationHome owner connects to curb stop valves at the property line. Energy meters allowmonthly energy billing…similar to water meter. Heat pump installations inside thebuilding are almost identical to a typical residential geothermal installation.The cost of the system to the homeowner is similar to installing a gas furnace and airconditioner when the cost of installing the GHX is eliminated. Green Building Festival – Evergreen Brick Works, Toronto, ON – October 11 & 12, 2012 Slide 20
  21. 21. District GeoExchange Systems Individual homeowner’s installation cost comparisonThe cost of installing the heat pump inside the home is almost identical to theinstallation of a gas furnace and air conditioner.The capital investment for the district GHX is made by the Town and amortized over 20years…the homeowner doesn’t have to make the investment for the GHX. Green Building Festival – Evergreen Brick Works, Toronto, ON – October 11 & 12, 2012 Slide 21
  22. 22. District GeoExchange Systems Benefits to the homeownerMonthly energy cost to the homeowner is approximately 35% less than electricresistance heating and 16% less than natural gas. In addition to energy cost savings,there is no outdoor air cooled condenser as with a conventional HVAC system.The homeowner pays the electric utility for the electricity used to run the heat pump aswell as a bill from the Town for the energy withdrawn or rejected to the district GHX. Green Building Festival – Evergreen Brick Works, Toronto, ON – October 11 & 12, 2012 Slide 22
  23. 23. District GeoExchange Systems Responsibility for constructionComponents of the system are the responsibility of different parties: • The Town of Gibsons installs the GHX and pump house. • The Developer installs the distribution piping and curb stop valves. • The home builder / home owner is responsible for connections & heat pump. • The Town maintains the GHX, pump house and distribution system Home builder or home owner Developer responsible to responsible for connect to construction of distribution piping distribution piping to homes The Town built the GHX & pump house Green Building Festival – Evergreen Brick Works, Toronto, ON – October 11 & 12, 2012 Slide 23
  24. 24. District GeoExchange Systems Responsibility for construction cost • Town installs, owns and operates the GHX and pump house. • Developer installs the distribution piping & curb stop valves, & turns it over to town • Home builder / owner is responsible for connections mechanical systemThe total cost of the energy source (GHX, pump house, distribution piping andconnections to home is approximately $8,100…20% to 40% less than individual GHX. DEVELOPER HOMEOWNER Distribution System Connection to system for 75 Homes $500 / home TOWN $178,300 GHX for 133 Homes $2,377 / home $601,300 $4,521 / home TOWN Pump House for 275 Homes $194,900 $709 / home Green Building Festival – Evergreen Brick Works, Toronto, ON – October 11 & 12, 2012 Slide 24
  25. 25. District GeoExchange Systems Incentives provide start up capitalTo enable this project to move ahead the Town was able to take advantage ofapproximately $569,000 of incentives to bridge the gap between the time constructionstarted and the Town could begin collecting enough revenue to service the debt.This is similar to the investment a gas or electric utility must make to build generatingstations and distribution infrastructure. Green Building Festival – Evergreen Brick Works, Toronto, ON – October 11 & 12, 2012 Slide 25
  26. 26. District GeoExchange Systems Economics – Town of Gibsons return on investmentThe Town of Gibsons will be invoicing customers like any other utility. Expectedrevenues from each type of home are shown in the chart below. The chart shows aninvestment of $695,590 for the homes in Phase 1 amortized over 20 years with aninterest rate of 3.5%.Return on investment is positive, but the Town must deal with the gap between buildingthe infrastructure and collecting revenue from it. Number of Monthly Total Annual Annual Loan Homes in Geothermal Utility Repayment Phase 1 Utility Bill Revenue Single 42 $948 $39,816 ---Cluster home 36 $264 $9,504 --- Cottage 55 $372 $20,460 --- Total 133 $69,780 $48,250 Green Building Festival – Evergreen Brick Works, Toronto, ON – October 11 & 12, 2012 Slide 26
  27. 27. District GeoExchange Systems Optimization of building & GHX is needed to make the economics workA GeoExchange system can be designed and built cost-effectively with: • Accurate energy modeling • Taking advantage of synergies between different buildings • Working with contractor resources available in the area • Determining a cost-effective GHX configuration for geology & land area available Green Building Festival – Evergreen Brick Works, Toronto, ON – October 11 & 12, 2012 Slide 27
  28. 28. District GeoExchange Systems Finding room for another utilityStreets in new developments are filled with utilities. Minimum distances must bemaintained from water supply lines and access to lines must be considered for futurerepairs and connections.In heating dominant climates consideration must be given to minimum GHXtemperatures if temperatures are expected to drop below freezing.Curbstop Curbstop box box Geothermal distribution lines Green Building Festival – Evergreen Brick Works, Toronto, ON – October 11 & 12, 2012 Slide 28
  29. 29. District GeoExchange Systems Future expansion of systemAs the development expands additional buildings are easily added to the system.Thoughtful city planning and architectural design can help make a district system moreviable. Green Building Festival – Evergreen Brick Works, Toronto, ON – October 11 & 12, 2012 Slide 29
  30. 30. District GeoExchange Systems Why district geothermal systems and why Gibsons would want one• Environment: BC mandates that communities reduce GHG emissions. When complete the estimated CO2 emissions will be reduced by 1,400 tonnes annually.• Revenue source: The investment in the complete district system is expected to have an internal rate of return of approximately 15% to 20%.• Community development: It is hoped forward thinking and demonstrating concern for the environment will help attract people to the community. Green Building Festival – Evergreen Brick Works, Toronto, ON – October 11 & 12, 2012 Slide 30
  31. 31. District GeoExchange Systems Future energy sources – data centersCooling data centers is costly…Waste energy from a data center could be fed into a GHX. This can be used to balanceenergy loads to and from a GHX reducing size and cost of the system, improve energyefficiency ensure long term sustainability. Green Building Festival – Evergreen Brick Works, Toronto, ON – October 11 & 12, 2012 Slide 31
  32. 32. District GeoExchange Systems Future energy sources - wasteTechnologies are available that convert waste into heat and electricity…helping urbanareas deal with several issues.A GHX can be used to integrate various energy sources and technologies. Green Building Festival – Evergreen Brick Works, Toronto, ON – October 11 & 12, 2012 Slide 32
  33. 33. District GeoExchange Systems Making full use of systems provides greater benefitsThe Enwave deep water cooling system, downtown Toronto, is one of the largest districtGeoExchange systems in the world.But it’s used only for cooling. If used for heating as well the system would be morebalanced and could do more. Green Building Festival – Evergreen Brick Works, Toronto, ON – October 11 & 12, 2012 Slide 33
  34. 34. District GeoExchange SystemsQuestions or comment? Green Building Festival 2012-10-12 District GeoExchange Systems Ed Lohrenz, B.E.S., CGD 1503 – 220 Portage Avenue Winnipeg, Manitoba 204-255-5959 ed@geoxergy.com Green Building Festival – Evergreen Brick Works, Toronto, ON – October 11 & 12, 2012 Slide 34

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