Overview of Geothermal Heat Pump Systems

Transcription

1 Overview of Geothermal Heat Pump Systems

2 Overview of Geothermal Heat Pump Systems Provider: EnLink Geoenergy Course ID: The U.S. Green Building Council (USGBC) has approved the technical and instructional quality of this course for 1 GBCI CE Hours towards the LEED Credential Maintenance Program. EnLink is an USGBC Education Provider committed to enhancing the ongoing professional development of the building industry and LEED Professionals through high-quality education programs. As a USGBC Education Provider, EnLink has agreed to abide by USGBC established operational and educational criteria, and is subject to annual reviews and audits for quality assurance. 1

3 Learning Objectives Determine whether geothermal heat pump systems are a feasible application for a project. Become aware of all system associated environmental benefits for goals towards sustainable design. Learn to have a strong understanding of the economics involved in system installation, and the savings achieved through energy and water conservation. How geothermal heat pump systems can apply towards LEED certification, and what categories of the LEED rating system GHPs will most likely contribute. 2

4 Building Statistics Building sector consumes 39% of U.S. primary energy. Heating, Ventilation, and Air Conditioning (HVAC) systems generally account for 20-60% of a buildings energy consumption Chart courtesy of DOE 3

5 Building Statistics Buildings account for 39% of all CO 2 emissions in the United States Most to all of the emissions are accounted for by the reliance of fossil fuel based energy sources Buildings consume approximately 75% of the electricity load in the U.S. This is the most significant contributing factor to buildings emissions HVAC systems are one of the major water consumers in buildings such as hotels, hospitals, schools, commercial buildings, shopping centers In a typical federal office building HVAC systems consume approximately 810 gallons of water per day. This accumulates to 296,000 gallons per year. Note: Chart courtesy of DOE 4

6 GHPs - A Solution GHPs are an existing technology that can cut energy use, water use, and carbon emissions GHPs are the only renewable technology that is available on-site, at every building s point of use. 5

7 Overview of Geothermal Heat Pump Systems Geothermal Heat Pump Systems Energy efficiency Heating and cooling Demand side renewable Also known as: geoexchange, ground source heat pumps, closed loop vertical geothermal, geothermal heating and cooling Geothermal Energy Hot rocks geysers Deep drilling to harness steam Power generation 6

8 Overview of Geothermal Heat Pump Systems The earth absorbs 50% of the sun s energy and stores it in the top surface layers in the form of constant, stable, moderate year-round temperature Geothermal heat pump (GHP) technology harnesses the constant, stable moderate temperature to heat and cool buildings It is an energy efficient way of heating and cooling buildings utilizing the constant temperature of the earth No Chillers or Boilers are used Ground is a heat source in the winter and heat sink in the summer Moves BTUs in and out of the ground. Demand side renewable Does not generate kilowatts Earth Heat Exchanger Replaces Chiller and Boiler 7

9 Overview of Geothermal Heat Pump Systems Power of GHP GHPs could avoid the need to build 91 to 105 GW of electricity generation capacity, or 42 to 48 percent of the 218 GW of net new capacity additions projected to be needed nationwide by 2030 $33 to $38 billion annually in reduced utility bills (at 2006 rates) could be achieved through aggressive deployment of GHPs GHPs have the potential to offset approximately 35 to 40 percent of the projected growth in building energy consumption between now and 2030 GHPs use the only renewable energy resource that is available at every building s point of use, on-demand, that cannot be depleted, and is affordable in all 50 states GHP infrastructure will outlive the building and many generations of heat pumps, and is similar to utility infrastructure poles, wires, underground natural gas piping, etc. Source: ORNL 8

10 Overview of Geothermal Heat Pump Systems Power of GHP U.S. EPA: Geothermal heat pumps can reduce energy consumption and corresponding emissions up to 44% compared to air-source heat pumps and up to 72% compared to electric resistance heating with standard airconditioning equipment The U.S. Department of Energy Office of Geothermal Technologies cite geothermal heat pumps are among the most energy-and cost-efficient heating and cooling systems available today The U.S. Department of Energy and the U.S. Environmental Protection Agency cite geothermal heat pumps as being ready today to effectively fight climate change, reduce air pollution and increase energy efficiency U.S. DOE: Up to 3-4 times more efficient than standard natural gas & electrical HVAC systems U.S. DOE: GHP can cut HVAC energy demand by 50% and overall energy demand by 35% 9

11 Overview of Geothermal Heat Pump Systems Mechanics/Principles GHP transfers heat in air from the building to the ground in summer & vice versa in winter Two Components Earth heat exchanger (EHX) is buried underground and located outside the building EHX acts much like a car s radiator Geothermal heat pump (GHP) located inside GHP controls air movement inside building to EHX Multiple GHPs may be used to decentralize & minimize heat/cooling losses The geothermal heat pump is easy to service and does not require specialized training Horizontal Units Vertical Units Console Units Vertical Stack Units 10

12 Overview of GeoExchange Systems Heat Pumps Water-Source Heat Pumps are the most versatile and comprehensive in the industry. Configurations include: Vertical stack / high rise Console Vertical water-to-air Horizontal water-to-air Large tonnage horizontal and vertical water-to-air Water-to-water Rooftop water-to-air Dedicated Outdoor Air Systems (DOAS) Source: ClimateMaster 11

13 Overview of Geothermal Heat Pump Systems Types of Systems Traditional HVAC System Generally 4 pipe chiller and boiler system Higher energy use, peak hours/pricing Utilizes fossil fuels Uses large amounts of water High maintenance, operating and replacement costs Generally highest single use of energy in most commercial or institutional buildings 12

14 Overview of Geothermal Heat Pump Systems Types of Systems Vertical Closed Loop Borefields usually near building Wells generally ft Wells usually spaced 20 x 30 Green area or parking lot or other open area usually above borefield Vertical loops typically used for commercial and institutional applications Few moving parts Lower chance of pipe damage versus horizontal Underground portion replaces Chillers and Boilers 13

15 Overview of Geothermal Heat Pump Systems Types of Systems Hybrid System A hybrid system replaces the boiler and chiller with ground loop and heat pumps, and augments ground loop with fluid cooler These often have better first cost economics than a pure GHP system in that they can significantly reduce the size of the EHX (borefield) Hybrids are most effectively employed in buildings with limited footprint for a borefield, severely cooling dominated loading characteristics (like Phoenix, Houston, etc), and high daytime peak power pricing During the day (high cost power time), the system runs off the EHX. Then at night, when the cost of power is usually cheaper and the heat exchange is more efficient, the fluid cooler is used to unload the EHX heat into the atmosphere 14

16 Overview of GeoExchange Systems Types of Systems Hybrid System (cont d) The concept is similar to ice/thermal storage in that you don t necessarily save as much energy, but by buying power offpeak, you can save money on fuel cost The downside of hybrids is that the total energy consumed can be greater than a pure GHP system and the maintenance is increased because of the fluid cooler requirement The primary advantage of hybrids is first cost savings and, as long as power companies use peak pricing schemes, energy (fuel) costs are mitigated 15

17 Overview of Geothermal Heat Pump Systems Benefits of GHP Significant reduction in energy use - up to 70% compared to traditional HVAC Reduces peak demand Base load application; demand side renewable Transmission (electricity, fuel) not required Versatile systems: Can work with any energy plan, including solar, wind, or conventional Significantly reduces power demand and makes renewable systems smaller, reducing costs for such renewables Biggest step toward - Zero Net Energy Buildings - LEED Certification Works the same everywhere; low variability; predictable; stable - Sun doesn t have to shine - Wind doesn t have to blow 16

18 Overview of Geothermal Heat Pump Systems Benefits of GHP Significant reduction in water use can save hundreds of thousands of gallons per year Lower maintenance, operating and replacement costs Systems can often produce domestic hot water as added benefit Durable Product GHP indoors - not subject to weather & vandalism Lower delta-t and fewer moving parts enhance longevity ASHRAE-rated lifespan of 26 years for long-term energy savings benefits Uses no water or natural gas on site No on-site emissions Greenhouse gas legislation home run 17

19 Economics GHP systems generally have a higher first cost than conventional HVAC systems, but the energy, water, maintenance and replacement savings can result in paybacks as little as two years, depending upon several factors Incentives further enhance the economics of the systems GHP systems provide powerful hedge against fluctuations in energy prices as well as utility peak pricing schemes 18

20 Qualifying a GeoExchange Candidate Key Criteria for Evaluation Building Size and Utilization Criteria "First Cost" - mobilization Considerations Sufficient run time to justify CAPEX Building Design /Energy Profile HVAC System Peak Demand Charges/Energy Prices/Current Utility Rates Heating: Natural Gas/Oil/Propane (cost) Cooling: 2 pipe system/central Plant Age and condition of the existing system Current maintenance cost vs. future Footprint and Physical Constraints Availability of parking lots or green space Trees/Existing Utilities Geology Local labor market Financial Customer Motivation Mud Rotary/Downhole Hammer/Sonic Prevailing Wage/Union/Drilling Contractors Federal ITC/Local Utility Incentives or Rebates LEED Qualification School (demonstration technology) Desire to be "Green" 19

21 Qualifying a GeoExchange Candidate Evaluating a Retrofit Candidate Easy (and relatively cheap): A single story finger school with window bangers can be directly replaced using console GHP units using a building perimeter loop tying the GHP units to the central borefield (or even several GHP units to an individual borehole) A 4-pipe system can be converted to GHP by eliminating the boiler and chiller and replacing them with GHP water-to-water units - utilizing the existing hydronic piping system, fan coil units, duct work, and most of the controls. (Montrose County building is an example) A rooftop DX package unit system can be directly replaced by a large GHP unit (or series of large units) specifically intended to mount directly on the existing HVAC curb - tying directly to the existing ductwork An in-floor hydronic heating system can be converted by replacing the gas, propane, oil, or electric boiler with a water-to-water GHP unit Any and all domestic hot water needs for the building can be easily converted to GHP by simply substituting a water-to-water unit for the electric or gas hot water heater(s) 20

22 Qualifying a GeoExchange Candidate Evaluating a Retrofit Candidate More Challenging: All high-rise buildings and complex special requirement buildings Buildings that must be retrofitted without disturbing occupants Converting old historic building with little or no interior space for ductwork or refrigerant drops Multistory concrete/steel building with difficult access for supply/return water lines Buildings with difficult access to the building and/or the drilling area 21

23 Qualifying a GeoExchange Candidate Preliminary Cost Estimate 1 Ton of Heating/Cooling rages from 150 ft (CO) to 600 ft (TX) There are always outliers, so as a rough rule, we assume ft per ton depending on location Utilizing the Regional Map on the following page allows us to estimate a very rough EHX installation cost per foot 300 or 400 ft per ton x estimated peak Heating/Cooling loads x price per foot = the rough EHX installation cost The mechanical portion of the work also ranges in price widely depending on the region- however several of the same factors that influence the price per foot to drill, also affect the mechanical scope (labor) Although it varies, as a general rule the mechanical scope is roughly equal in cost to the EHX portion We have utilized this method with great success in the past- even in predicting the anticipated cost of publicly bid projects 22

24 Qualifying a GeoExchange Candidate Preliminary Cost Estimate U.S. Geo Markets 23

25 Qualifying a GeoExchange Candidate Preliminary Cost Estimate Project Example: Eastside Elementary School, Georgia EHX Project Cost Components Actual Bid Price Mobilization *Drill rigs are costly to mobilize Location Project Name Eastside Eastside Elementary Drill *Drill rigs are costly to mobilize/wage rates can be extremely high/variable drilling conditions Loop/Grout *Labor intensive/ctu Trench *Competent rock and large boulders Header/Manifold *Design is the biggest factor in price/vault vs. Manifold construction Testing Bores 210 Depth 250 Total Feet 52,500 COGS $408, Trenching $25, Project Direct Margin 0.15 $61, Contingency 0.10 $40, Sales Price $535, Price per foot $

26 Incentives Depending on ownership of the systems, it may be possible to take advantage of the strong Federal, State and Local Incentives associated with GHPs Incentives alone could result in a 1-2 year payback Federal Incentives (GHPs are considered a renewable technology) 10% investment tax credit Depreciation deduction using MACRS $0.30-$1.80/ft 2 tax deduction State and Local Incentives Each state offers different incentives, but many offer rebates through utilities which can be applied to equipment or peak kwh saved, energy savings grants, sales tax exemption, and others. 25

27 Who is Using GHP Systems? Traditionally utilized in the U.S. by government and public institutions Military Schools Other public buildings More widespread use in Europe Private sector beginning to embrace GHP technology WalMart Walgreens IKEA JCI Headquarters 26

28 Overview of GeoExchange Systems GHP Market Market is growing Positive factors in marketplace: High profile projects Renewables standards Stimulus and DoE funding State energy efficiency programs Barriers to Entry Still generally low awareness Fragmented market, no industry "voice Higher up front costs Lack of technical expertise Trade organizations both help and hurt cause 27

29 Overview of Geothermal Heat Pump Systems The State of the Geothermal Heat Pump System Industry: 1. A Sizable Market Showing Strong Growth: Total U.S. Market 2008 = ~ $2.5 billion Total U.S. Market 2010 = ~ $4.4 billion 30% growth over last couple years Growth rate expected to continue at ~30% over the next few years Growth rate to increase: Financing and Technical Knowledge aspects Predicted U.S. Market 2014 = ~$12 billion 2. Stable and Predictable Technology Returns on Investment/Costs of System provided by technology and fuel displacement. (This is unlike wind or solar that heavily rely on fed/state incentives) 3. Demand will only increase over the next years 28

30 Overview of Geothermal Heat Pump Systems Systems Work Well for Most Applications Commercial Buildings Statue of Liberty Gift Shop ASHRAE Headquarters - Atlanta, GA Galt House Hotel - Louisville, KY Black Point Inn - Prouts Neck, ME Alta Condos, Washington DC Harvard Library Cambridge, MA French Laundry Rest.- Napa, CA Whistler Village - BC, Canada Yale Art Bld. New Haven, CT Gaillardia Offices Okla. City California University of PA Hirschfeld Towers Denver, CO 29

31 GHPs and LEED Certification Energy And Atmosphere Prerequisite 1 Commissioning process for GHP system Prerequisite 2 Minimum energy performance Option 1 Demonstrate 10% improvement building performance rating for new construction, 5% for retrofits Option 2 ASHRAE advanced energy design guide Option 3 Advanced building core performance guide Prerequisite 3 Fundamental Refrigerant Management Credit 1 Optimize Energy Performance Option 1 Whole building energy simulation (0-19 points) : Demonstrate a percentage improvement in the proposed building performance rating compared with the baseline building performance rating 19 points : 48% improvement on new construction, 44% on retrofits GHPs meet all prerequisites, and are capable of reducing energy consumption by up to 72% compared to traditional HVAC, and total building energy consumption up to 50%, which could result in the maximum 19 points for Credit 1 in the Energy and Atmosphere category 30

32 GHPs and LEED Certification Through their many benefits and environmentally sound designs, GHPs help contribute towards earning points in many other certification categories and credits Water Efficiency: Credit 3 Water Use Reduction: (2-4 points) GHPs are not named specifically as a water saving fixture nor are they outside the scope of water reduction calculations: GHPs reduce potable water consumption and could help meeting water reduction percentages Energy and Atmosphere: Credit 4 Enhanced Refrigerant Management: (2 points) GHPs use water as a working fluid in their earth heat exchanger and a non-toxic refrigerant in the actual heat pump, eliminating ozone contributing emissions Indoor Environmental Quality: Credit 6.2 Controllability Systems Thermal Comfort (1 point): Credit 7.1 Thermal Comfort Design (1 point) GHPs are capable of simultaneous heating and cooling, and the systems can be designed to accommodate separate thermal control for every room in a building GHPs are most suitable to earn points for energy efficiency but have strong potential to earn points in the above credits 31

33 LEED Certified Buildings w/ GHPS Holy Wisdom Monastery Madison, WI LEED platinum, 63/69 points under LEED v2.2 rating system Highest rated LEED platinum building ever (2010) Banner Bank Building Boise, ID LEED platinum First building in ID to receive LEED platinum The Phillip Merrill Center Annapolis, MD LEED platinum recognized as being one of the world s most energy efficient buildings Select EnLink Projects with LEED certification Las Vegas PBS Facility, NV LEED gold This building is estimated to save 45% of normal energy costs RTC Centennial Plaza, NV LEED silver Use of geothermal heating and cooling was in efforts in achieving LEED certification City College of San Francisco Joint Use Facility, CA Goal of LEED platinum the geothermal system for this facility will connect to four other buildings. 32

34 Calculating Savings: Case Study CCSF Case Study 33

35 Calculating Savings: Case Study CCSF Case Study SF City College Life Cycle Cost Estimate Assumptions: C02 is $100/ton, CA C02 electricity emissions factor is 0.8 lbs/kwh, real water inflation rate is 3%, real electricity inflation rate is 1%, real natural gas inflation rate is 4%, cooling load is 369 tons, heating load is 313 tons., average geothermal system efficiency is 17EER (GEER)/4.6 COP, conventional system efficiency is 12.5 SEER (cooling) and 90% (heating). Annual run time is 1548 hours (cooling) and 1274 hours (heating). Electricity is $0.11/kwh, natural gas is $1.50/therm and water/sewage is $0.0038/gallon 34

36 Calculating Savings: Case Study CCSF Case Study SF City College Life Cycle Cost Estimate Annual Costs Costs Over Life of Installation 300,000 14,000, ,000 12,000,000 10,000, , , ,000 Other Water CO2 Emissions Maintenance Energy 8,000,000 6,000,000 4,000,000 Other Water CO2 Emissions Maintenance Installation Energy 50,000 2,000,000 0 Geothermal Traditional HVAC 0 Geothermal Traditional HVAC 35

37 Case Studies: Nevada Northwest Technical and Career Academy (Clark County SD) New Construction 220,000 ft 2 building area 400 ton system capacity 80/20 geo/traditional hybrid system 420 boreholes, 400 ft depth Estimated Energy Savings of 40% compared to a typical school of the same size Confidential and 36 Veterans Tribute Career and Technical Academy (Clark County SD) New Construction 131,000 ft 2 building area 500 ton system capacity 60/40 geo/traditional hybrid system 200 boreholes, 400 ft depth Estimated Energy Savings of 25 35% Estimated 750,000 gallons of water saved annually

38 Case Studies: Nevada Heritage Park Senior Center and Aquatics Complex (Henderson) Retrofit 71,000 ft 2 building area LEED Gold Rating 180 boreholes, 400 ft depth 0.9 million kwh annual energy savings $136,000 annual utility savings Las Vegas PBS Facility (Las Vegas) New Construction 112,000 ft 2 building area 350 ton system capacity LEED Gold Rating 200 boreholes, 300 ft depth Estimated Energy Savings of 45% Local Utility Incentives Confidential Received: and $90,000 37

39 About EnLink 15 years experience in providing turn key geothermal systems Successfully installed projects throughout the U.S. New construction and retrofits All building types Most applications Most geological formations and climates Successful track record in marketplace Specialize in institutional, municipal and federal markets; expanding into commercial Work closely with geothermal designers, energy modelers, mechanical engineers as well as prime contractors/construction management Own outright all equipment; have own crew Demonstrated technological advantages Perform both THM and DLG work, ensuring quality and consistency throughout project Strong private equity backing 38

40 EnLink Geoenergy Services, Inc Homestead Place Rancho Dominguez, CA : Work : Cell Albert Escobedo 39