Geothermal handbook: PlanninG and Financing power Generation t e c h n I c a L r e p o r t 2 / 2

F I g u r E 1 . 1 4
Concept of Condensing Geothermal Power Plant
Source | Modified from Dickson and Fanelli 2004.
Turbine
Generator
Steam
Separator
Water
Reinjection Well
Production Well
Condenser
Cooling Water Pump
Cooling Tower
Steam
Water
A double flash steam cycle differs from a single flash cycle in that the hot brine is passed through 
successive separators, each at a subsequently lower pressure. The steam is directed to a dual-entry 
turbine in which steam at different pressures flow to different parts of the turbine. This increases overall 
cycle efficiency and better utilizes the geothermal resources, but at an overall increase in capital 
cost. The decision as to whether or not a double flash plant is worth the extra cost and complexity 
can only be based on a thorough economic evaluation of the cost of developing and maintaining the 
geothermal fluid supply, the power plant costs, and the value of the electricity to be sold (Bloomquist 
and Knapp 2002).