Hybrid and Advanced Air Cooling Geothermal Lab Call Project

From Open Energy Information

Last modified on July 22, 2011.

Project Title Hybrid and Advanced Air Cooling
Project Type / Topic 1 Laboratory Call for Submission of Applications for Research, Development and Analysis of Geothermal Technologies
Project Type / Topic 2 Air-Cooling
Project Description Many geothermal power plants in the U.S. are air-cooled because of water limitations. NREL has worked with industry to explore various strategies for boosting the performance of air coolers in hot weather. Computer modeling and experimental measurements have been done on the use of evaporative media upstream of the air-cooled condensers at the Mammoth Lakes Power Plant. NREL has also analyzed the use of an air-cooled condenser in series with (i.e., upstream of) a water-cooled condenser and found that this can be beneficial for power cycles requiring desuperheating of the turbine exhaust vapor. Recently, the conventional power industry has developed an interest in operating water- and air-cooled condensers in parallel. This arrangement allows a small water cooler to reduce the heat transfer duty on the air cooler on hot summer days thereby allowing the condensing working fluid to make a much closer approach to the air dry bulb temperature.
State Colorado
Objectives Identify and analyze advanced cooling strategies that allow air-cooled geothermal power plants to maintain a high electric power output during periods of high air dry bulb temperatures while minimizing any water consumption.
Awardees (Company / Institution) National Renewable Energy Laboratory

Funding Opportunity Announcement DE-PS36-09GO99017
DOE Funding Level (total award amount) $875,000.00
Total Project Cost $875,000.00

Principal Investigator(s) Charles Kutscher

Targets / Milestones - Perform an hour-by-hour cost/performance simulation of cost-optimized 50 MW binary-cycle geothermal power plant at resource temperatures of 125C and 175C for three different heat rejection systems; water-cooled, air-cooled, and cost-optimized hybrid cooling system.

- Identify an appropriate binary-cycle plant to conduct a field test of the performance of the hybrid cooling system.
- Demonstrate advanced air-cooling through field testing.

Location of Project Golden, CO

Funding Source American Recovery and Reinvestment Act of 2009
References EERE Geothermal Technologies Programs[1]


  1. EERE Geothermal Technologies Programs