LESSON LEARNED: COSO

Andrew E. Sabin, PhD, PG Geothermal Program Office, US Navy

California Geothermal Forum: A Path to Increasing Geothermal Development in

California October 20, 2016

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Coso geothermal field, NAWS China Lake

What is Coso?

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Coso geothermal field, NAWS China Lake

What is

GPO?

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GPO exploration sites

Salton Sea

region, CA

Hawthorne Army Depot, NV

NAS Fallon, NV

Guam

Tularosa Basin, NM, DOE Play Fairway

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NEPA

•Environmental and cultural

•Expandable

•Long-lived

•Locally archived

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Sundry notice process

•Non-revocable

permit

•Tiered off EA/EIS

•Rapid turn-

around

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Sensible royalty structure

•Consider both parties interests

• Ideal is staged royalty structure

• Incentivizes contractor

•Long-term viability of project

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Injection strategy

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Geologic map/geologic model

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Plan for water augmentation

•Assume it will be required

•Have infrastructure in place

•Permitting well ahead of time

•Make sure injection capacity exists

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Drill deep early

•Drill deep early

•All steam

production as

long term

strategy is not

sustainable

•Larger capital

investment up

front

•But drilling costs

go up

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Drilling and development

• Injection v. production well design. Pinpointing injection to

specific depths needs to be a consideration in injection well design.

•Develop in stages. Understand the chemistry and productivity of

the field before making huge investments in large facilities. Without

this approach, it is easy to overbuild beyond sustainable levels, and

one may become subject to constant retrofits and high capital outlays

after the projects have been built.

•Enthalpies and gas Weren’t really considered useful as

management tools initially. The better understanding of these

characteristics has informed decisions on injection, HP to LP well

conversions, and turbine configurations.

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Efficiency thoughts

Consider sooner than later:

–bottoming cycles (esp. when brine

levels are high)

–Solar augmentation for parasitic load

–Solar hybrid

–Meq

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Partnering/relationships, Pt. 1

•Partner with experience

personnel with a proven

track record.

•Geothermal tends to fail

the elevator speech test

(subsurface and plant

operations)

• It should not be treated

as a “science project

(e.g., EGS, some binary,

etc.).”

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Partnering/relationships, Pt. II

•Develop synergistic

relationships

•Focus on resource

•Have a GPO

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Collaboration and communication

“The art of communication is the language of

leadership.”

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Andrew E. Sabin, PhD, PG

Geothermal Program Office, US Navy

andrew.sabin@navy.mil 760.939.2700

719.373.3531

Thank you