How It Works

Organic Rankine Cycle Process

The Organic Rankine Cycle (ORC) converts thermal energy into electricity. It does this using a process similar to a steam turbine, but it uses refrigerant instead of water. This allows the ORC to extract energy from low temperature sources.

  1. The heat source transfers thermal energy into the refrigerant causing it to vaporize.
  2. High pressure refrigerant vapor flows into the turbine.
  3. The refrigerant vapor pushes against the turbine and causes it to spin.
  4. The turbine turns the generator producing electrical power.
  5. Cooling water extracts thermal energy from the low pressure refrigerant vapor.
  6. The refrigerant is condensed back into liquid.
  7. Liquid refrigerant is pumped into the evaporator.

Organic Rankine Cycle Terminology

Binary Cycle

A geothermal power plant that allows cooler geothermal reservoirs to be used with dry steam or flash steam plants.

Carefree® Integrated Power Module (IPM)

Core of the Thermapower® and Hydrocurrent™ systems, which consists of a high-speed turbine expander and high-efficiency generator supported by frictionless magnetic bearings and enclosed in a hermetically sealed housing.

Closed-Loop System

The process of waste or liquid being treated and returned for reuse (recycled).


A mechanism that condenses vapor into liquid.


Recovering heat from brine and gas produced by oil and gas wells.

Energy Recovery

The process of converting non-recyclable waste into accessible heat, electricity or fuel.


An apparatus used to turn liquid chemicals into their gas form, which is evaporated or vaporized into a gas.

Extra Low Temperature

The 125 XLT optimal heat source temperature is 95.6⁰C (204⁰F).

Geothermal Power

Recovering heat from hot springs and brine produced by geothermal drilling to produce electricity. A geothermal Organic Rankine Cycle system is often used to convert the heat into power.

Heat Exchanger

An instrument that transfers heat from one medium to another.

Hermetically Sealed Unit

The outer packaging used to maintain a seal against the flow of gases, liquids or chemicals.

Medium Temperature

The 125 MT optimal heat source temperature is 135⁰C (275⁰F).

Organic Rankine Cycle (ORC)

Is a heat recovery process that converts thermal energy into mechanical power.

Renewable Energy

Energy from an inexhaustible source, such as wind or solar power.

Solar Thermal Power

Using energy from the sun to generate thermal energy.

Thermodynamic Cycle

A sequence of thermodynamic processes that involve transfer of heat and work into and out of the system.


Centrifugal or axial flow turbine through which a high pressure gas is expanded to produce work.

Utility Interconnection

Connection to public utility electrical grid.

Waste Heat Recovery

Converting wasted heat into useable electric power.

Working Fluid

A fluid, such as R245Fa, that has a particular set of physical properties essential for the operation of a thermodynamic cycle.