Our customers are facing a challenging future. They want a flexible and viable partner to support them in a world of changing expectations. EthosEnergy turns on potential to deliver services and solutions globally for rotating equipment to make energy affordable, available and sustainable. A unique combination of partnership and service quality, backed by a track record of tailored solutions, for the power, oil & gas, industrial and aerospace markets. EthosEnergy operates in over 100 countries to consistently improve performance across the value chain.

Geothermal steam turbine retrofit

Due to the continued steam decline of the geothermal reservoir, the single operating turbine at Tiwi Geothermal Plant (TGP) operated at approximately half capacity and resulted in inefficient steam consumption.


  • Increase Steam Production
  • Life Extension
  • Increase Power Output


  • Power generation


  • Steam turbines


  • Tiwi, Philippines

Project Overview

Due to the continued steam decline of the geothermal reservoir, the single operating turbine at Tiwi Geothermal Plant (TGP) operated at approximately half capacity and resulted in inefficient steam consumption.

Key Challenges

  • Operator faced with a decreased amount of flow from the geothermal resource
  • The turbine which was designed for 60MW was producing less than 30 MW
  • The operator was also faced with a steam path which was deteriorated
  • Customer keen to minimize cost by using as much of the components that were fit for service as possible
  • Unexpected discoveries such as discrepancies in the design of various units caused complications in both the steam path as well as stationary components

The EthosEnergy Solution

EthosEnergy performed a thermodynamic and mechanical analysis of the existing unit and assessed what improvements could be made. From this analysis the turbine diaphragms and blades for three of the six stages were redesigned by reducing the blade height. Since new blades and diaphragms were required, EthosEnergy changed the design to an integral covered configuration with replaceable tip spill strips in the diaphragm. This change eliminated one of the biggest issues on geothermal steam turbine blades which is tenon erosion. The integral cover design eliminates the tenon and allows for improved sealing.

The analysis indicated that six stages were still the best design but the nozzle mouth heights had to be reduced on stages 4 & 5. Even though the steam specific volume went up, the flow required to make the target output of 32.2 MW was lower than the original design volume flow. Nozzle and blade flow passing areas were also changed to account for the change in total volume flow and to distribute the loading optimally across each stage.

Project Highlights

Key highlights of the project

Collaboration between EthosEnergy and Aboitiz Power

Ensured the most cost-effective results by minimizing costs and using as many of the existing components that were fit for service.

Redesign and Modifications

A method of redesign and modifications assured that test results exceeded performance guarantees.

Key Results

The test results exceeded the performance guarantees. The result was a mix of new components for stages 1, 2 & 3 and modifications to stages 4 & 5 to reach a balance between cost and performance gains.

The new steam path was analyzed for the new conditions and material selected to provide improved reliability. The asset now has an extended life due to the well thought out program and execution.


After completion AP Renewables saw an increase in both steam rate and efficiency. The unit steam rated improved by 10% and efficiency by 14%

Connect Now

This question is for testing whether or not you are a human visitor and to prevent automated spam submissions.

Other Articles

What future-proofing looks like for the energy market

EthosEnergy’s suite of life extension and emissions compliance solutions aims to make energy affordable, available, and sustainable for its clients.

EthosEnergy nominated for Optimisation Award at the EIC Awards 2022

EthosEnergy has been shortlisted for the Optimisation category in the Energy Industries Council (EIC) Awards 2022, which recognizes companies who focus on improving internal decision-making, costs, processes, agility, structures, and enhancing competitiveness.

Chlorine compressor upgrade

A large chemical company contacted our Hengelo, Netherlands operation for a new titanium impeller for a chlorine compressor and upgrade.

Gas turbine rotor overhaul

EthosEnergy was contracted to provide gas turbine rotor overhaul for a European refinery.

Reduced outage and costs on a D-11 steam turbine

Patented leading edge restoration process on L-0 titanium blades for a D-11 steam turbine for a large utility company in the southeast US. 

Turnkey water injection upgrade on frame 9EA units

A simple-cycle peaking facility in the arid desert of northern Chile was facing strict emissions regulations that required modifications to their two Frame 9EA, 126 MW Gas Turbines

EthosEnergy promotes innovative and sustainable solutions for the energy industry in Israel

One of the significant trends in the formulation of Israel's energy policy is the adoption of a circular model that offers efficient use of resources in industrial plants and power plants, to slow down the effects of the climate crisis and accelerate the transition to sustainable energy.

EthosEnergy Union Field Services wins silver at Safety Excellence Awards

EthosEnergy Union Field Service team from the Gulf Coast was awarded the silver award for Safety Excellence at the 35th annual Houston Safety Excellence Awards Gala.

EthosEnergy awarded multi-million dollar operations and maintenance contract extension by TexGen Power

Houston, TX – EthosEnergy has secured a multi-million dollar operations and maintenance (O&M) contract extension by TexGen Power for the operation of three power generation assets in Texas.

EthosEnergy Announces Patricia Gonzalez as Executive Vice President, West Hemisphere

Houston, TX – EthosEnergy, a global independent service provider for critical rotating equipment, announces the appointment of Patricia Gonzalez as Executive Vice President for the West Hemisphere.

EthosEnergy Keeps Telfer Site Operational During Cyclone

Telfer, Australia – On Thursday, April 13, the Western Australian coast witnessed Isla, a Category 5 cyclone which left the Telfer mine in its direct path. The site was predicted to receive the force of a Category 3 cyclone around midday on April 14, leaving the site owners, Newcrest, with a difficult decision to make.

EthosEnergy Appoints Former ItalPresseGauss CEO, Mario Cincotta as New East Hemisphere Executive Vice President

Aberdeen, United Kingdom--(Newsfile Corp. - March 14, 2023) - EthosEnergy has appointed Mario Cincotta, former CEO of ItalPresseGauss and Senior Vice President of Norican Group, as its new Executive Vice President of East Hemisphere. Mario will have strategic and operational leadership for the East Hemisphere. He will be based in Italy and report into the CEO, Ana Amicarella.