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Developing Geothermal Energy in
the Pacific Northwest
The Energy Under Our Feet
2
Geothermal Energy
The deeper you go the hotter
it gets.
AltaRock Confidential
Using the Earth’s Heat TodayHydrothermal Sources – On line now
• Drill wells into fractured or porous rock• Pump or self-flow water to surface• Direct use of heat
– Heating and cooling
– Industrial processes – food drying, washing
– Aquaculture
• Power Generation– Flashed Steam
– Binary
– Dry Steam
Combined heat and power at Chena Hot Springs, Alaska
4
Binary vs. Flash
Flashed Steam Plants- Most geothermal power plants operating
today are "flashed steam" power plants.
� Hot water is passed through one or two separators � Released from the pressure of the deep reservoir, part of it flashes (explosively boils) to steam. � The force of the steam spins the turbine generator. � The geothermal water and condensed steam are directed down aninjection well back into the periphery of the reservoir, to be reheated and recycled.
Navy I dual flash plant at Coso
AltaRock Confidential
5
Binary vs. Flash
Binary Power Plants -
� Geothermal water is passed through one side of a heat exchanger
� Heat is transferred to a second (binary) liquid, called a working fluid
� The fluid boils to vapor which, like steam, powers the turbine generator.
� Then condensed back to a liquid and used over and over again.
Binary plant at Empire, NV
AltaRock Confidential
Altarock Confidential6
Environmental Impact of EGS• Plant emissions
– No plant emissions with binary plants
– With flash plants, plant emissions extremely low, can be mitigated
• Drilling and site preparation– Relatively small land disturbance – Several wells drilled from one 100
ft x 300 ft pad– Plant is small, one story high– Rock cuttings and reservoir fluids
benign with EGS resources
• Transmission line routing– Projects can be located near
transmission lines– Projects can be located away from
scenic areas
AltaRock Confidential7
The Future of Geothermal EnergyThe Future of Geothermal Energy: Impact of Enhanced Geothermal Systems(EGS) on the United States in the 21st Centuryhttp://geothermal.inel.gov/publications/future_of_geothermal_energy.pdf
– 12 member panel lead by Dr. Jeff Tester through MIT
– Includes preliminary assessment of US resource
• Conclusions:
– Technically feasible today
– Best resources economic today
– Resource extends across US
– 50,000 MW of EGS power could be on line by 2050 with no federal investment
– 100,000 MW by 2050 ~$350,000,000 net federal investment
Next Generation Geothermal Technology
Enhanced Geothermal Systems• Benefits
– Like hydrothermal – Renewable, baseload, low cost to operate, low cost volatility
– Uses same plant technology and drilling infrastructure as hydrothermal
– Scalable – modular development to very large projects
– Small footprint– Less site specific– Low to no resource risk – technology
based– Technically feasible today
• Challenges– High up front cost – 75%-80% in
wellfield
EGS TechnologyHow it works
Where Do We Find It?
• Volcanic areas
• Thin crust
• Deep sedimentary basins
• Deep faulting
Volcanic Areas – The Cascades
Magmatic heat source
Mt. Jefferson
Thin Crust – Basin and RangeCrustal thinning brings heat close to the surface in the Basin and Range, the Rhinegraben in Europe.
Geothermal well test in the Basin and Range of Nevada
Deep Sedimentary Basins
Radioactive decay of isotopes in graniticbasement rocks is trapped by insulating sediments.
Geopressured geothermal power plant test at Pleasant Bayou, LA
Deep Faulting
Faults extending deep in the earth bring high temperature fluids near the surface.
Test of new well for district heating system, Boise, Idaho. Deep faulting brings hot water to shallow depths in Boise, other areas of Idaho.
Geothermal Potential of the Pacific Northwest
EconomicsHigh Temperature System
300°C at 4 km
• With current technology ~12.5¢/kWh• With improved technology 9.5¢/kWh
• Areas for technology improvement– Conversion cycle efficiency– Drilling cost reduction/risk reduction
• Fewer casing strings• Higher hard rock ROP• Better measurement while drilling for HT
(risk↓)
– Improved stimulation technology• Better zone isolation
• Better reservoir understanding– Stress measurement– Fracture ID– Higher flow per producer
– Single well test methods
AltaRock Confidential16
EconomicsLow Temperature System
150°C at 5 km• With current technology ~21.5¢/kWh• With improved technology 10.4¢/kWh• Areas for technology improvement
– Conversion cycle efficiency• Improved HT pumping• More efficient binary cycle
– Drilling reduction/risk reduction• Fewer casing strings• Higher hard rock ROP• Better measurement while drilling for HT
(risk↓)
– Improved stimulation technology• Higher flow per producer!• Better zone isolation• Better reservoir understanding
– Stress measurement– Fracture ID– Single well test methods
% of LCOE, Baseline System
Other w ellf ield-Pipes, pumps, stimulation
Wells
Contingency
Exploration
Royalty
Pow er Plant
% of LCOE, Improved System
Other w ellf ield-Pipes, pumps, stimulation Wells
Contingency
ExplorationRoyalty
Pow er Plant
AltaRock Confidential17
Available EGS Power at Cost
AltaRock Confidential18
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0 500,000 1,000,000 1,500,000 2,000,000 2,500,000
Co
st in
¢/k
W/h
Developable Power Assuming 30 Year Project Life in MWe
Supply Curve for EGS Power in the United States
Current Technology
Near Term Incremental Improvements
GETTING POWER ON LINE
• Increase capacity at 10% per year• Develop hydrothermal first
• EGS at best sites starting in 2013
• EGS expands at 20% per year until 2025
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MW
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Geothermal Development to Reach 20% of US Electric Power
Geothermal MW on Line
Cum EGS on line
CO2 Displaced in metric tons
WHAT DO WE NEED TO GET POWER ON LINE?
• Land– Exploration– Development
• Investment
• Equipment– Rigs– Steam turbines– Binary power plants
• People– Technical – Resource– Technical – Plant – Rig crews– Plant operations
0
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2005 2010 2015 2020 2025 2030 2035 2040 2045 2050
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What We Need - EGS 20% of US Electric Power Supply
New Wells
Rigs
People (Plant Ops)
Rig Crews
Technical-Resource
Technical-Plant
Construction
$0
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Land and Investment - Geothermal as 20% of US
Power Supply
Acres of Developable Land Acres of land needed for exploration Investment Private
How Do We Make This Happen?
• Risk reduction• Drilling cost reduction• Improved stimulation –
greater flow per producer• Increased conversion
efficiency• Longer reservoir life
QuickTime™ and aYUV420 codec decompressor
are needed to see this picture.
Geothermal Energy In A Carbon-Constrained Future
AltaRock Confidential25
• Using EGS technology we can achieve:• 10 percent growth per year in geothermal power on line• Reach >100,000 MW by 2045 in the US alone• Displace 1.4 billion metric tons per year of CO2• Based on incremental improvements in existing technologies • Uses existing infrastructure
• Future technology improvements could achieve:• Major CO2 offsets • CO2 sequestration while generating power• Significant improvements in efficiency• Reductions in cost to less than half cost with current
technology
