GEOTHERMAL PROJECT COST ESTIMATING

1. GEOTHERMAL PROJECT COST ESTIMATING By Lorie M. Dilley

2. Flow-Chart Flow-Chart Geothermal Projects Geothermal Projects Construction Management Civil, Geotechnical & Transportation Design & Engineering Construction Management Civil, Geotechnical & Transportation Design & Engineering EXPLORATION EXPLORATION Geochemistry Geology Hydrology Prefeasibility Studies Environmental Feasibility Geochemistry Geology Hydrology Prefeasibility Studies Environmental Feasibility $200+/kW Drilling success rate<25% $200+/kW Drilling success rate<25% Confirm Size of the Project Temperature and Depth of Resource Confirm Size of the Project Temperature and Depth of Resource Project Management Planning Cost Estimating Permitting Project Management Planning Cost Estimating Permitting PRODUCTION PRODUCTION Drilling success rate 70 – 80% Generating Plant ~ $1300-$6000/kW Transmission Line, Access Roads, piping, etc add to costs... Drilling success rate 70 – 80% Generating Plant ~ $1300-$6000/kW Transmission Line, Access Roads, piping, etc add to costs... CONFIRMATION CONFIRMATION Drilling success rate ~60% Costs per well can easily exceed 2M$ Drilling success rate ~60% Costs per well can easily exceed 2M$ HDL HDL HDL HDL Go / No Go Decision Go / No Go Decision

3. Exploration – chemical, geophysical, aerial photos

4. Drilling Costs • Wells – Determine # of wells based on temperature, flow rate, and production required. • MW/well = F/50 – 3.5 (temp. > 175 F) • 200 F: 0.5 MW • 400 F: 4.5 MW • Low temperature 0.1 to 0.4 MW/well • Drilling success rate 25% to 80% increase as knowledge of field increases

5. Temperature “Gradient” holes

6. Drilling Costs • Slim hole/temperature gradient Drilling: 3 to 4 inch • 3,000 ft: $1.5 to $2 M • Production Drilling: 9 to 12 inch • 3,000 ft : $3.9 to $4.3 M • 5,000 ft: $4.5 M – 30 to 40 days of drilling • 8,000 ft: $7.5 M • Alaska Factor: 1.25 to 2 times

7. Infrastructure Needs • Construction – camp, access, skilled workforce • Plant – power generation, piping, geothermal wells, waste fluid disposal – trained operators • Support Facilities – transmission line, road, living quarters, water supply & storage, wastewater treatment, maintenance shop, drilling equipment/ core shop, • Facilities: greenhouses, pools, rooms

8. Power Production

9. Plant Costs UTC System : 200 to 250 kW is about $1,300 per KW $260,000 Binary System: $1,600 to $2,400 per kW : 1 MW to 5 MW -$1.6M to $2.4M Steam Plants: $1,500 per kW 5 MW to 25 MW - $7.5M to $37.5M

10. Support Facilities • Roads – equipment, access wells,: gravel sources estimated cost is $30 to $250 per cubic yard depending upon material source location and quality – route selection critical • Site Development – pads for plant, shops, living quarters, greenhouses – gravel, placement • Transmission line – route selection – closer to village – power use $200,000 to $400,000+ per mile

11. Costs • < 1 MW: UTC - $7M to $30M • 1 MW to 10 MW : Binary - $40M to $100M • Greater than 10 MW: Steam - $100M to $400M Based on drilling depths, gravel costs, temperature of resource, flow, size of project.