GEOTHERMAL PROJECT COST ESTIMATING

By

Lorie M. Dilley

Exploration – chemical, geophysical, aerial photos

Drilling Costs

• Wells – 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

Temperature “Gradient” holes

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

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

Power Production

Plant Costs

UTC System : 200 to 250 kW is about $1,300 per KW UTC System : 200 to 250 kW is about $1,300 per KW $260,000 $260,000Binary System: $1,600 to $2,400 per kW : Binary System: $1,600 to $2,400 per kW :

1 MW to 5 MW -$1.6M to $2.4M1 MW to 5 MW -$1.6M to $2.4MSteam Plants: $1,500 per kWSteam Plants: $1,500 per kW

5 MW to 25 MW - $7.5M to $37.5M5 MW to 25 MW - $7.5M to $37.5M

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

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.