Potential Improvements to Existing Geothermal Fields in California

1
Potential Improvements to Existing Geothermal
Fields in California

• GRC 2006 Annual Meeting
• San Diego, California, 12 September 2006

Presented by Jim Lovekin GeothermEx, Inc.
2
Authors

• Jim Lovekin GeothermEx Inc.
• Subir Sanyal GeothermEx, Inc.
• Adil Caner Sener George Washington University
• Valentino Tiangco California Energy Commission
• Pablo Gutiérrez-Santana California Energy
  Commission

3
Acknowledgements

• California Energy Commission
• Public Interest Energy Research (PIER) Program
• San Francisco Public Utilities Commission
• Hetch Hetchy Water and Power
• Ronald DiPippo
• Geothermal Power Plants (2005)
• Ray Dracker
• Center for Resource Solutions

4
CEC Reports

• 2004 - New Geothermal Sites
• Focus on California and western Nevada
• Provide realistic estimates of MW available
• Estimate capital costs to bring power on line
• 2006 - Improvements at Existing Facilities
• Focus on existing geothermal plants within
  California
• Describe and quantify potential improvements in
• Resource supply
• Surface facilities
• Estimate capital costs and OM costs

5
GEOTHERMAL FACILITIES

• 45 geothermal power plants in California
• 7 geothermal fields
• Coso
• East Mesa
• Heber
• Honey Lake
• Mammoth Pacific (Long Valley)
• Salton Sea
• The Geysers

6
CAPACITY DEFINITIONS

• Terminology to provide basis for comparisons
• Original capacity (rated, nameplate)
• Electro-mechanical capacity (capability)
• Allows for conditions better than design
• Accounts for turbine modifications, if known
• 2005 capacity (gross and net MW)
• Accounts for limitations of resource supply
• Actual annual average power (net MW)

7
CAPACITY AMOUNTS

• Totals for Seven California Fields
• Original capacity 2,680 MW gross
• Electro-mechanical capacity 2,640 MW gross
• 2005 capacity 1,830 MW gross
• 1,600 MW net
  
• Actual annual average power 1,500 MW net
• Most-Likely Resource Capacity 3,900 MW
  gross
• (2004 CEC Report)

8
POTENTIAL FROM IMPROVEMENTS INRESOURCE SUPPLY

• Electro-mechanical capacity
• minus
• 2005 capacity (gross)
• Total 810 MW gross
• Geysers alone 760 MW gross
• This is the amount of power that existing
  California geothermal plants could generate if
  there were no limitations of resource supply.

9
POTENTIAL FROM IMPROVEMENTS INSURFACE FACILITIES

• Most-likely resource capacity
• minus
• Electro-mechanical capacity
• Total 1,600 MW gross (excluding Geysers)
• Salton Sea alone 1,400 MW gross
• This is the the amount of incremental power
  
  
  
  that could be achieved by improvements in
  existing plants (assuming no increase in resource
  supply) or by constructing new plants in
  currently producing fields.

10
GEYSERS SPECIAL CASE

• Electro-mechanical capacity exceeds most-likely
  resource capacity
• Surplus in plant capacity is concentrated in
  certain areas other areas remain underdeveloped
• Potential for new capacity at The Geysers that
  would not interfere excessively with existing
  plants 100 to 150 MW (Calpine)

11
EXAMPLE OF RESOURCE SUPPLY IMPROVEMENT
Effect of injection augmentation in southeast
Geysers
12
EXAMPLE OF SURFACE FACILITY IMPROVEMENT
Advanced direct-contact condenser at Calpine Unit
11
13
FRAME OF REFERENCE FORCOST COMPARISONS

• Capital costs for new geothermal plants
• 2,900 to 3,500 per kW installed
• (2005 dollars)
• OM costs for existing geothermal plants
• 2.0 to 2.5 /kWh

14
OM DEFINITION

• Includes
• Labor and benefits
• Services and supplies
• Property taxes
• Royalties and lease payments
• Insurance
• Workovers
• Administrative costs at plants
• Excludes
• Financing costs
• Depreciation
• Ongoing capital expenditures

Note Financing typically adds several /kWh to
effective cost of operating geothermal facilities
needs to be considered in determining price at
which operators can sell power.
15
CONCLUSIONS

• Improvements to existing geothermal facilities
  are worth considering if less than the cost of a
  new plant, i.e. capital costs less than about
  2,900 per kW improvement.
• OM savings of a fraction of a cent per kWh can
  be significant in comparison to total OM in the
  range of 2.0 to 2.5 /kWh.