Geothermal Systems - nhjes
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1 Geothermal Heating/Cooling Systems Presented to: NH Joint Engineering Societies 6 th Annual Conference Presented by: David G. Lamothe, P.E. Senior Project Manager GZA GeoEnvironmental, Inc. Manchester, New Hampshire Date: October 4, 2012
Transcript of Geothermal Systems - nhjes
Slide 16th Annual Conference
Senior Project Manager GZA GeoEnvironmental, Inc. Manchester, New Hampshire
Date: October 4, 2012
• Photos and Case Studies
Low temperature thermal exchange (~40-90°F)
Uses renewable energy stored in the
earth to heat and cool
5
6
Why Geothermal?
To do your own comparison based on current fuel prices, your system’s efficiency, etc., go to: www.nhclimateaudit.org/calculators.php
Fuel Type Fuel Unit Cost Fuel Unit of Measure
Efficiency of Heating Unit
Price per Million Btu
No. 2 Fuel Oil 3.661 Gallon 78% 33.84
Natural Gas 1.0556 Therm 78% 13.53
Propane 3.178 Gallon 78% 44.61
Wood 210 Cord 60% 17.50
Electricity 0.13706 kWh 99% 40.56
Wood Pellets 243.86 Ton 80% 18.47
Kerosene 3.968 Gallon 80% 36.74
Geothermal 0.13706 kWh 330% 12.17
Heating Cost Comparison
Note: Fuel Unit Costs are based on average prices in the State of New Hampshire as of September 3, 2012.
0 10 20 30 40 50 60 70 80 90
100
(4 to 6 kW)
GEOEXCHANGE SYSTEM
GEOEXCHANGE SYSTEM
(EXTRACTS BTUs)
Vault/manifold
Hybrid System
• Economic and/or design decision to optimize performance and limit capital costs
• Combine geothermal wells and heat pumps
with: – Chillers or cooling towers to boost cooling – Solar thermal collectors to boost heating – Supplemental fossil fuel for heating
To serve peak demand that occurs only a portion of total operating time
16
0
200
400
600
800
1000
1200
1400
1600
1800
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Lo ad
(M B
17
to water or air distributed to the building
Media: – Water-to-water (hydronic systems) – Water-to-air
Distribution System • Ducted forced air system • Hydronic/Chilled Beams • Radiant floor (hydronic) heating with
ducted cooling
Ground Heat Exchanger (Ground Loop)
Exchanges heat with the ground – Open to Diffusion Wells (ODW) – Standing Column Wells (SCW) – Closed Loops (CL)
• Vertical • Horizontal
19
• Typ. used in highly transmissive aquifers (Cape Cod, Long Island)
• More efficient
• More maintenance than closed loops (water quality can cause fouling)
Extraction Well
Injection Well
Available depth to water for injection
Ratio of injection wells to extraction wells may be 2:1 to 4:1
Open Loop System
• Typically 1,500 feet deep
• Efficiency comes from advective heat transfer
• Performance is dependent upon quality of water encountered and ability to bleed
Typ. 6.5 in. diam. in rock, uncased
20’ (min.) into rock
Drywell, water body
Induces Flow to Well Issues: Responsibly discharged to same aquifer Subject to permitting requirements Environmental Concerns? Foundation Settlement?
23
Deviation
Most projects require 0.01 ft/ft = 15 ft Then there’s reality……
210 feet away from point of entry!
24
Deviation
Stabilizers and low down pressure used to limit deviation.
25
Deviation
NY State – oil and gas regulations require a deviation or verticality survey for all wells (incl. geothermal) > 500 feet deep unless MWD techniques used.
NH, MA – no requirement - yet…..
26
•Ground temperature, thermal conductivity and diffusivity important
•Lower maintenance than open systems
27
29
Disadvantages • Suitable Soils Needed • Thermally Inefficient • Long Lengths Needed
30
Disadvantages • Limited Application • Primarily for cooling • Regulatory Issues • Environmental Impacts
31
Logistics
Closed loop closer spacing but more wells typ. required
Geology Soil, bedrock, and groundwater conditions
Depth to rock, water quantity and quality
Unstable rock – CL recommended
AUR/AUL?
33
Client’s risk tolerance Permitting
O&M / Cost (Estimated payback period)
Water quality issues - Poor water quality (i.e. high Fe, Mn or hard water, low pH) – CL recommended to avoid scaling and fouling issues
(Risk tolerance is often primary factor in selection)
Selection of Ground Loop
(Underground Injection Control)
More rigorous permitting for Open Loop vs. Closed Loop UIC registration for CL Open systems (Open, SCW):
UIC registration
Water Use Registration and Reporting for > 20,000 gpd (~14 gpm) – report monthly use on a quarterly basis
Groundwater Withdrawal Program (>57,600 gpd = 40 gpm) needs large groundwater withdrawal permit
35
Raw Water Quality Testing Required for VOCs Primary inorganics (As, nitrate/nitrite) Radiological (Gross Alpha/Beta, Radium, Uranium) Secondary inorganics (Na, Cl, Fe, Mn) pH, temperature, TDS Bacteria (total coliform [fecal and E. coli]) for discharge
water
36
Propylene glycol Ethanol Also Methanol, Potassium Acetate, Calcium Magnesium Acetate (CMA)
Pipe Materials HDPE Fiberglass
37
(Underground Injection Control)
More rigorous permitting for Open Loop vs. Closed Loop 1 page UIC registration for CL Open systems – UIC registration, water withdrawal
reporting/registration/permitting for > 100,000 gpd (=70 gpm), [determination of non-consumptive use]
38
Selected Organics Primary inorganics (As, nitrate/nitrite) Radiological (Gross Alpha/Beta, Radium, Uranium) Secondary inorganics (Na, Cl, Fe, Mn) pH Bacteria (total coliform [fecal and E. coli]) for discharge
water
Bleed – should return to same aquifer If > 5% to different aquifer, requires justification
39
40
Federal Tax Credits (sunset 2013 comm/2016 res)
State Tax Credits in some states
Utility Rebates
Where to Start? Database of State Incentives for Renewables & Efficiency
(“DSIRE”, www.dsireusa.org) http://energy.gov/savings
7 to 15 years typical
<7 years possible, particularly for older systems in need of replacement due to avoided costs
Look at Life Cycle Costs (Capital, O&M)
42
• Are LEED objectives being met? • System operating instructions/debug
No one should be tied to a certain method or technology
43
“State of the Practice” for Geothermal?
Phase I - Feasibility Study Educate owners Due Diligence to evaluate anticipated conditions and
recommend a ground loop type for the site GZA w/ Energy Modeler, System Designer input Recommend a ground loop type (SCW, CL, ODW) Test well
Phase II - Design Plans and Specifications System Designer w/ GZA input
Phase III - Well Field Construction Driller w/ GZA observation
44
“State of the Practice” for Geothermal?
Phase I - Feasibility Study Educate owners Due Diligence to evaluate anticipated conditions and
recommend a ground loop type for the site GZA w/ Energy Modeler, System Designer input Recommend a ground loop type (SCW, CL, ODW) Test well
45
Test Well
• Test well or “first” well of the geothermal well field for consideration in design of remaining well field
• Obtain site-specific geologic information (soil, depth to and type of rock, groundwater quantity and quality)
• Estimate thermal properties via thermal conductivity test (CL)
• Pump test and water quality testing (SCW or ODW)
46
Installation of Geo-loop
Mud rotary with 12-inch stabilizer to 20’ into rock, set 8” dia. casing
•Drill rig •Auxiliary compressor/ support truck •Booster compressor •Two rolloff dumpsters •Two open weir tanks and one frac tank
47
(Credit: Water Energy)
20’ (min.) into rock
6.5” dia. air rotary to 1,500 ft.
48
Drilling 6-inch borehole
6-inch mud rotary bit used to set temp./perm. casing into rock, then air rotary to bottom of hole
49
Installation of Geo-loop
51
GZA and Geothermal – 3-Phase Approach
Phase I - Feasibility Study Due Diligence to evaluate anticipated conditions and
recommend a ground loop type for the site GZA w/ Energy Modeler, System Designer input Recommend a ground loop type (SCW, CL, ODW) Test well
Phase II - Design Plans and Specifications System Designer w/ GZA input
Phase III - Well Field Construction Driller w/ GZA observation
52
• Circuit Piping Configuration
Main supply and return
Electrofusion
61
T ot
al S
ys te
m C
os t (
$0 00
Case Studies and Cost Comparisons
Consider Life-Cycle
Costs! 30 year cost includes O&M, Monitoring and Reporting
62
Mission To educate and advocate for the advancement of
the Geothermal Heat Pump industry in New England to increase energy efficiency and reduce
dependency on fossil fuels
• Information on NEGPA [email protected]
603-232-8716 [email protected]
Open Loop System
Slide Number 20
Standing Column Well
What is “Bleed?”
Test Well
Well Field Construction
Well Field Construction
Well Field Construction
Well Field Construction
Well Field Construction
Well Field Construction
Well Field Construction
Well Field Construction
Well Field Construction
Questions?
Senior Project Manager GZA GeoEnvironmental, Inc. Manchester, New Hampshire
Date: October 4, 2012
• Photos and Case Studies
Low temperature thermal exchange (~40-90°F)
Uses renewable energy stored in the
earth to heat and cool
5
6
Why Geothermal?
To do your own comparison based on current fuel prices, your system’s efficiency, etc., go to: www.nhclimateaudit.org/calculators.php
Fuel Type Fuel Unit Cost Fuel Unit of Measure
Efficiency of Heating Unit
Price per Million Btu
No. 2 Fuel Oil 3.661 Gallon 78% 33.84
Natural Gas 1.0556 Therm 78% 13.53
Propane 3.178 Gallon 78% 44.61
Wood 210 Cord 60% 17.50
Electricity 0.13706 kWh 99% 40.56
Wood Pellets 243.86 Ton 80% 18.47
Kerosene 3.968 Gallon 80% 36.74
Geothermal 0.13706 kWh 330% 12.17
Heating Cost Comparison
Note: Fuel Unit Costs are based on average prices in the State of New Hampshire as of September 3, 2012.
0 10 20 30 40 50 60 70 80 90
100
(4 to 6 kW)
GEOEXCHANGE SYSTEM
GEOEXCHANGE SYSTEM
(EXTRACTS BTUs)
Vault/manifold
Hybrid System
• Economic and/or design decision to optimize performance and limit capital costs
• Combine geothermal wells and heat pumps
with: – Chillers or cooling towers to boost cooling – Solar thermal collectors to boost heating – Supplemental fossil fuel for heating
To serve peak demand that occurs only a portion of total operating time
16
0
200
400
600
800
1000
1200
1400
1600
1800
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Lo ad
(M B
17
to water or air distributed to the building
Media: – Water-to-water (hydronic systems) – Water-to-air
Distribution System • Ducted forced air system • Hydronic/Chilled Beams • Radiant floor (hydronic) heating with
ducted cooling
Ground Heat Exchanger (Ground Loop)
Exchanges heat with the ground – Open to Diffusion Wells (ODW) – Standing Column Wells (SCW) – Closed Loops (CL)
• Vertical • Horizontal
19
• Typ. used in highly transmissive aquifers (Cape Cod, Long Island)
• More efficient
• More maintenance than closed loops (water quality can cause fouling)
Extraction Well
Injection Well
Available depth to water for injection
Ratio of injection wells to extraction wells may be 2:1 to 4:1
Open Loop System
• Typically 1,500 feet deep
• Efficiency comes from advective heat transfer
• Performance is dependent upon quality of water encountered and ability to bleed
Typ. 6.5 in. diam. in rock, uncased
20’ (min.) into rock
Drywell, water body
Induces Flow to Well Issues: Responsibly discharged to same aquifer Subject to permitting requirements Environmental Concerns? Foundation Settlement?
23
Deviation
Most projects require 0.01 ft/ft = 15 ft Then there’s reality……
210 feet away from point of entry!
24
Deviation
Stabilizers and low down pressure used to limit deviation.
25
Deviation
NY State – oil and gas regulations require a deviation or verticality survey for all wells (incl. geothermal) > 500 feet deep unless MWD techniques used.
NH, MA – no requirement - yet…..
26
•Ground temperature, thermal conductivity and diffusivity important
•Lower maintenance than open systems
27
29
Disadvantages • Suitable Soils Needed • Thermally Inefficient • Long Lengths Needed
30
Disadvantages • Limited Application • Primarily for cooling • Regulatory Issues • Environmental Impacts
31
Logistics
Closed loop closer spacing but more wells typ. required
Geology Soil, bedrock, and groundwater conditions
Depth to rock, water quantity and quality
Unstable rock – CL recommended
AUR/AUL?
33
Client’s risk tolerance Permitting
O&M / Cost (Estimated payback period)
Water quality issues - Poor water quality (i.e. high Fe, Mn or hard water, low pH) – CL recommended to avoid scaling and fouling issues
(Risk tolerance is often primary factor in selection)
Selection of Ground Loop
(Underground Injection Control)
More rigorous permitting for Open Loop vs. Closed Loop UIC registration for CL Open systems (Open, SCW):
UIC registration
Water Use Registration and Reporting for > 20,000 gpd (~14 gpm) – report monthly use on a quarterly basis
Groundwater Withdrawal Program (>57,600 gpd = 40 gpm) needs large groundwater withdrawal permit
35
Raw Water Quality Testing Required for VOCs Primary inorganics (As, nitrate/nitrite) Radiological (Gross Alpha/Beta, Radium, Uranium) Secondary inorganics (Na, Cl, Fe, Mn) pH, temperature, TDS Bacteria (total coliform [fecal and E. coli]) for discharge
water
36
Propylene glycol Ethanol Also Methanol, Potassium Acetate, Calcium Magnesium Acetate (CMA)
Pipe Materials HDPE Fiberglass
37
(Underground Injection Control)
More rigorous permitting for Open Loop vs. Closed Loop 1 page UIC registration for CL Open systems – UIC registration, water withdrawal
reporting/registration/permitting for > 100,000 gpd (=70 gpm), [determination of non-consumptive use]
38
Selected Organics Primary inorganics (As, nitrate/nitrite) Radiological (Gross Alpha/Beta, Radium, Uranium) Secondary inorganics (Na, Cl, Fe, Mn) pH Bacteria (total coliform [fecal and E. coli]) for discharge
water
Bleed – should return to same aquifer If > 5% to different aquifer, requires justification
39
40
Federal Tax Credits (sunset 2013 comm/2016 res)
State Tax Credits in some states
Utility Rebates
Where to Start? Database of State Incentives for Renewables & Efficiency
(“DSIRE”, www.dsireusa.org) http://energy.gov/savings
7 to 15 years typical
<7 years possible, particularly for older systems in need of replacement due to avoided costs
Look at Life Cycle Costs (Capital, O&M)
42
• Are LEED objectives being met? • System operating instructions/debug
No one should be tied to a certain method or technology
43
“State of the Practice” for Geothermal?
Phase I - Feasibility Study Educate owners Due Diligence to evaluate anticipated conditions and
recommend a ground loop type for the site GZA w/ Energy Modeler, System Designer input Recommend a ground loop type (SCW, CL, ODW) Test well
Phase II - Design Plans and Specifications System Designer w/ GZA input
Phase III - Well Field Construction Driller w/ GZA observation
44
“State of the Practice” for Geothermal?
Phase I - Feasibility Study Educate owners Due Diligence to evaluate anticipated conditions and
recommend a ground loop type for the site GZA w/ Energy Modeler, System Designer input Recommend a ground loop type (SCW, CL, ODW) Test well
45
Test Well
• Test well or “first” well of the geothermal well field for consideration in design of remaining well field
• Obtain site-specific geologic information (soil, depth to and type of rock, groundwater quantity and quality)
• Estimate thermal properties via thermal conductivity test (CL)
• Pump test and water quality testing (SCW or ODW)
46
Installation of Geo-loop
Mud rotary with 12-inch stabilizer to 20’ into rock, set 8” dia. casing
•Drill rig •Auxiliary compressor/ support truck •Booster compressor •Two rolloff dumpsters •Two open weir tanks and one frac tank
47
(Credit: Water Energy)
20’ (min.) into rock
6.5” dia. air rotary to 1,500 ft.
48
Drilling 6-inch borehole
6-inch mud rotary bit used to set temp./perm. casing into rock, then air rotary to bottom of hole
49
Installation of Geo-loop
51
GZA and Geothermal – 3-Phase Approach
Phase I - Feasibility Study Due Diligence to evaluate anticipated conditions and
recommend a ground loop type for the site GZA w/ Energy Modeler, System Designer input Recommend a ground loop type (SCW, CL, ODW) Test well
Phase II - Design Plans and Specifications System Designer w/ GZA input
Phase III - Well Field Construction Driller w/ GZA observation
52
• Circuit Piping Configuration
Main supply and return
Electrofusion
61
T ot
al S
ys te
m C
os t (
$0 00
Case Studies and Cost Comparisons
Consider Life-Cycle
Costs! 30 year cost includes O&M, Monitoring and Reporting
62
Mission To educate and advocate for the advancement of
the Geothermal Heat Pump industry in New England to increase energy efficiency and reduce
dependency on fossil fuels
• Information on NEGPA [email protected]
603-232-8716 [email protected]
Open Loop System
Slide Number 20
Standing Column Well
What is “Bleed?”
Test Well
Well Field Construction
Well Field Construction
Well Field Construction
Well Field Construction
Well Field Construction
Well Field Construction
Well Field Construction
Well Field Construction
Well Field Construction
Questions?
