Patent ID: 8667799

Claim:
A method for operating a plurality of independent, closed cycle power plant modules, each having a closed motive fluid circuit including at least one vaporizer, an expander and a condenser, comprising the steps of: supplying a medium or low temperature source fluid to a vaporizer of a first one of said power plant modules to vaporize the motive fluid in the motive fluid circuit of said first power plant module, and expanding the vaporized motive fluid in the motive fluid circuit of said first power plant module to produce power; supplying the medium or low temperature source fluid exiting said vaporizer of the first one of said power plant modules to a vaporizer of a second one of said power plant modules to vaporize the motive fluid in the motive fluid circuit of said second power plant module, and expanding the vaporized motive fluid in the motive fluid circuit of said second power plant module to produce power; supplying the medium or low temperature source fluid exiting said vaporizer of the second one of said power plant modules to a secondary preheater in the motive fluid circuit of said first power plant module, wherein said secondary preheater is provided in the motive fluid circuit of said first power plant module at a location such that preheated motive fluid exiting said secondary preheater is supplied to said vaporizer of said first power plant module; supplying the medium or low temperature source fluid exiting said secondary preheater in the motive fluid circuit of said first power plant module to a vaporizer of a terminal one of said power plant modules to vaporize the motive fluid in the motive fluid circuit of said terminal one of said power plant modules, whereby the medium or low temperature source fluid becomes a heat depleted source fluid, and expanding the vaporized motive fluid in the motive fluid circuit of said terminal power plant module to produce power; and supplying the heat depleted source fluid in parallel to a primary preheater for the closed motive fluid circuit of each one of said first, second and terminal power plant modules, wherein the primary preheater of the first one of said power plant modules is provided in the motive fluid circuit thereof at a location such that preheated motive fluid exiting said primary preheater is supplied to said secondary preheater of said first power plant module.