Overview of Geothermal Heat Pump Systems
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Overview of Geothermal Heat Pump Systems
Overview of Geothermal Heat Pump Systems
Provider: EnLink Geoenergy
Course ID: 0090006198
“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
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
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
Building Statistics
Buildings account for 39% of all CO2 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
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
Overview of Geothermal Heat Pump Systems
Geothermal Heat Pump Geothermal Energy
Systems
Energy efficiency “Hot rocks” “geysers”
Heating and cooling Deep drilling to harness steam
Demand side renewable
Power generation
Also known as: geoexchange, ground
source heat pumps, closed loop vertical
geothermal, geothermal heating and
cooling
6
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. Does not generate kilowatts
Demand side renewable
Earth Heat
Exchanger
Replaces
Chiller and
Boiler
7
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
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 air-
conditioning 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%
9Overview 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
Horizontal Units Console Units
• Geothermal heat pump (GHP) located inside
GHP controls air movement inside building
to EHX
• Multiple GHPs may be used to decentralize & Vertical Units Vertical Stack Units
minimize heat/cooling losses
• The geothermal heat pump is easy to service
and does not require specialized training
10Overview 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 Water-to-water Rooftop water-to-air Dedicated Outdoor Air Systems
vertical water-to-air (DOAS)
Source: ClimateMaster
11Overview 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
12Overview of Geothermal Heat Pump Systems
Types of Systems
Vertical Closed Loop
Borefields usually near building
Wells generally 200 - 500 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
13Overview 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
14Overview 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 “off-
peak”, 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
15Overview 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
16Overview 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’
17Economics
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
18Qualifying a GeoExchange Candidate
Key Criteria for Evaluation
Criteria Considerations
Building Size and Utilization "First Cost" - mobilization
Sufficient run time to justify CAPEX
Building Design /Energy Profile Peak Demand Charges/Energy Prices/Current Utility Rates
HVAC System 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 Mud Rotary/Downhole Hammer/Sonic
Local labor market Prevailing Wage/Union/Drilling Contractors
Financial Federal ITC/Local Utility Incentives or Rebates
Customer Motivation LEED Qualification
School (demonstration technology)
Desire to be "Green"
19Qualifying 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)
20Qualifying 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
21Qualifying 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 300-400 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
22Qualifying a GeoExchange Candidate
Preliminary Cost Estimate
U.S. Geo Markets
23Qualifying a GeoExchange Candidate
Preliminary Cost Estimate
Project Example: Eastside Elementary School, Georgia
EHX Project Cost Components Actual Bid Price
Mobilization Location Eastside
*Drill rigs are costly to mobilize Project Name Eastside Elementary
Drill Bores 210
*Drill rigs are costly to mobilize/Wage rates can be extremely
high/Variable drilling conditions Depth 250
Loop/Grout Total Feet 52,500
*Labor intensive/CTU COGS $408,778.48
Trench Trenching $25,000.00
*Competent rock and large boulders Project Direct Margin 0.15 $61,316.77
Header/Manifold Contingency 0.10 $40,877.85
*Design is the biggest factor in price/Vault vs. Manifold
construction Sales Price $535,973.10
Testing Price per foot $10.21
24Incentives
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/ft2 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.
25Who 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
26Overview 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
27Overview 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 20-30+ years
28Overview 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
29GHPs 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
30GHPs 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
31LEED 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.
32Calculating Savings: Case Study
CCSF Case Study
33Calculating 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
34Calculating 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
250,000
10,000,000
200,000
Other
Other
8,000,000 Water
Water
150,000 CO2 Emissions
CO2 Emissions
Maintenance
Maintenance 6,000,000
Installation
Energy
100,000 Energy
4,000,000
50,000
2,000,000
0 0
Geothermal Traditional HVAC Geothermal Traditional HVAC
35Case Studies: Nevada
Northwest Technical and Veterans Tribute Career
Career Academy (Clark and Technical Academy
County SD) (Clark County SD)
New Construction New Construction
220,000 ft2 building area 131,000 ft2 building area
400 ton system capacity 500 ton system capacity
80/20 geo/traditional hybrid 60/40 geo/traditional hybrid
system system
420 boreholes, 400 ft depth 200 boreholes, 400 ft depth
Estimated Energy Savings of Estimated Energy Savings of
40% compared to a typical 25 – 35%
school of the same size
Estimated 750,000 gallons of
Confidential and water saved annually
36Case Studies: Nevada Heritage Park Senior Las Vegas PBS Facility Center and Aquatics (Las Vegas) Complex (Henderson) New Construction Retrofit 112,000 ft2 building area 71,000 ft2 building area 350 ton system capacity LEED Gold Rating LEED Gold Rating 180 boreholes, 400 ft depth 200 boreholes, 300 ft depth 0.9 million kWh annual Estimated Energy Savings of energy savings 45% $136,000 annual utility savings Local Utility Incentives Received: Confidential and $90,000 37
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
38EnLink Geoenergy Services, Inc.
2630 Homestead Place
Rancho Dominguez, CA 90220
424-242-1219: Work
323 868 5228: Cell
Albert Escobedo
aescobedo@enlinkgeoenergy.com
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