CERM3 Presentation

1
Geothermal Research Opportunities at CERM3 Mory
Ghomshei and John Meech Department of Mining
Engineering University of British Columbia

• Overview of geothermal energy
• Opportunities for Canada
• Opportunities for BC
• Case studies

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Concept

• ? Earth is a hot planet. It appears cold on
  the surface but the temperature increases rapidly
  with depth to reach 5000 oC at the center.
• Geothermal Energy is the extractable portion of
  the heat stored in the ground.
• The total accessible heat energy beneath the
  populated areas of Canada is 10 25 Joules (i.e.
  3 kW for each Canadian for 4 million years)

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Geothermal Quality

• Wide-spread geothermal resources are at low to
  medium temperature. They can be extracted for
  direct-use applications (heat exchangers and/or
  heat pumps).
• A small portion of geothermal energy is at
  high-temperature capable of generating electric
  power
• Three components of a geothermal resource are
• - heat,
• - water, and
• - permeability
• One of the readily accessible resources
  of low-grade
• geothermal energy is groundwater using
  a heat pump .

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Availability

• Known high- and medium-temperature geothermal
  resources are available along the coastal
  range
• Most Canadian cities are located on extensive
  groundwater aquifers with relatively constant
  temperature ( 9 to 15 C )
• Medium-grade geothermal resources are found in
  some areas from coast to coast (especially in
  B.C., Yukon and Alberta), where the temperature
  gradient is higher than normal. These
  resources can be tapped into by deep drilling.
• Aquifers are capable of storing extra heat from
  summer for use in winter (aquifer
  thermal energy storage, ATES).

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Applications

• Near surface aquifers can supply municipalities
  with energy
• and potable water
• Extracted geothermal heat from near-surface
  aquifers can be
• used for space heating, aquatic centers, and
  municipal waste
• treatment
• A system can also be designed for cooling
  (reverse cycle),
• using the ground water as a heat sink.
• Medium-grade geothermal resources accessible by
  deep drilling
• in high-temperature gradient areas can be used
  for waste water
• treatment, and other direct applications (e.g.
  space heating)
• High-grade geothermal resources can be
  used to generate
• electric power
• Abandoned underground mine workings are
  excellent
• geothermal heat-exchangers

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Geothermal Regions in Canada
Canadian Sedimentary Basin and Shield Deep-circula
ting waters
Young volcanics
Hot dry rock
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Basic Geothermics of Heat Mining Canadian
Resource Base
The Earth has a positive outward heat
flow Average Canadian temperature gradient is 30
C/km T (C) 10 0.03 Z (m) ?T 0.03
?Z ?Q mc ?T c 0.3 cal/g ?Q 0.009m
?Z for ?Z 4000m over the lower 500 km of
Canada ?Q 2 x 1022 cal 10,000 billion
barrels of oil considering 5 recovery of 5
of the land ?Q 25 billion barrels of oil
500 billion
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Low grade heat mining Green energy is available
from coast to coast
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Open Loop Systems Groundwater Geothermal Heat
Pump Advantages High efficiency
System reliability Heat storage Disadvantage
s Drilling/Pumping/ Re-injection/Water
management
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Fire and Water at peace Mercury and Mars in dance
Water provides the best heat storage among all
common substances
1 lb Lead 74 F 1 lb Lead 40 F 1 BTU
1 lb water 74 F 1 lb water 40 F 34 BTU
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Efficiency of a GHP depends on the resource
temperature and the supply water temperature
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Geothermal drilling at the Lynn Valley Care Centre
Rotary 90 deep 12 ft screen
in water bearing sand
North Vancouver, British Columbia
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Geothermal production well (Lynn Valley Care
Centre) 28 GPM continuous production _at_ 11 oC 25
kWt net capacity
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Lynn Valley Care Centre Geothermal Project Cost
analysis for a single well
Continuous production
28 GPM Resource temperature
11 oC Return from heat
pump 6
oC Supply water temperature
45 oC Coefficient of performance
4.2 Total heat capacity
of the well 37.0
kWt Electric power requirement for heat pump
8.8 kWe Electric power requirement for water
pump 0.4 kWe Total electric power
requirement 9.2 kWe Net
thermal power generated
27.8 kWt Capacity factor
70 Price of electricity
5
/kWh Net saving
12,200/year Total capital
cost
25,000
15
Britannia Mine (a classic site of Acid Rock
Drainage)
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Britannia Mine Effluent at the 2200 level prior
to plug
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Power supply (1MWe)
District heating supply (5 MWt)
15 oC
50 oC
13.5 oC
Geothermal Source
Heat pump
Heat exchanger
8 oC
Waste water
35 oC
6 oC
20 oC
Disposal/re-injection
Makeup water
10 oC
Geothermal District Heating Conceptual case
similar to the Britannia Beach resource
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Britannia Beach Geothermal plan Turning a
liability into asset
Mine effluent (combined flow at 4100 level)
Average yearly peak flow
1000 m3/h Average yearly low flow
400 m3/h Conservative yearly average
600 m3/h Effluent temperature
15 oC
Heat pump return
7 oC Supply water temperature
50 oC Total heat recovered
5.6 MWt Heat pump
COP
4.5 Electric power requirement for heat pump 1.25
MW Net thermal power generation
4.35 MWt Capacity factor
70 Net potential income
1,330,000/y Estimated
capital cost
2,200,000
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Gold Under Your Land (energy stored
in a home-based aquifer) Aquifer thickness
20 m Surface Area 450
m2 Porosity
15 Reservoir temperature 12 C Rejected
water 5 C Total
recoverable stored heat 50, 000 KWh 1/6 of the
energy is stored in the water 5/6 of the energy
is stored in the rock Energy is renewed
each summer

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Costs / Savings 70 savings in heating 50
savings in cooling Additional capital costs
recovered in 2 to 3 years for medium/large
systems 4 to 8 years for small
systems Capital costs Small size systems (2
kW)10,000 Medium size systems (100 kW) 200,000
Geothermal heat pump is one of the
fastest-growing alternative energy
technologies in Canada coast to coast
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High-grade Geothermal Energy An alternative for
B.C.
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Three components of geothermal energy 1- heat
2- water 3- permeability
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Cal-Energy Navy 1 flash steam - Coso Geothermal
field, California
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Geysers produces the cheapest and
cleanest electricity in the United States In
operation since 1960 at a capacity of 1500 to
2000 MW
A typical geothermal well-head (Geysers
California)
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Geothermal Energy accounts for 1/5th of
the total electric power generation in the
Philippines
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Flash Steam Geothermal Power Plant
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Binary geothermal cycle (for medium temperature
resources)
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Environmental Benefits No GHG emissions
No Acid Rain gas emission Totally renewable
and sustainable
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• Economic Benefits
• Environmental cost saving
• Diversification
• Local generation

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Electricity from renewable energy sources in 1998
(compiled from data in WEA 2000)
Geothermal is the leading renewable energy in
the world
31
Status of electricity production from
renewable data compiled from WEA 2000 (for 1998)
Geothermal is the most economical renewable energy
32
Location of the two high-enthalpy geothermal proje
cts in Canada
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South Meager Creek Deep Exploration
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Meager Creek reservoir and plan for production
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Opportunities for advancing the technology Heat
mining in areas with high geothermal
gradient (Hot Dry Rock) good for Atlantic
Provinces Enhancing reservoir permeability by
hydro-fracturing Heat recovery from abandoned
and operating mines Reservoir simulation for low
and high grade reserves Underground heat storage
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Conclusion
Geothermal is a renewable clean energy resource
It can be economically extracted at different
grades Low-medium grade is available from coast
to coast. Some old mine working can provide
cheap heat Canadian high-grade geothermal
resources in BC can contribute significantly
to the growing energy market in the Pacific
North West Geothermal energy is a true clean
alternative for Canada CERM3 is presently
engaged in RD on several
geothermal and heat mining projects in B.C.
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Oil fields will tumble Coal and gas will
crumble But heat from mother earth is here to
stay