Re-rate your steam turbine for an improved bottom line

Re-rates are one of the most powerful tools in a plant owner’s toolkit. 

Whether you’re dealing with changing steam conditions, excessive use of PRVs, or needing an increase in power, a re-rate can boost the profit of your plant. 

But what exactly does a re-rate involve? When is the right time to consider one? And how can you make sure you’re not just putting a band-aid over a problem, but actually boosting the long-term value? 

In this article, we’ll take a closer look at steam turbine re-rates – what they are, when to act, and how EthosEnergy helps you reimagine what your turbine is capable of. 

What is a re-rate?

Put simply, a steam turbine re-rate involves re-engineering a turbine to change its ideal design condition. 

That could mean:

• Flowing more steam (and generate more power)
• Adjusting for changed steam conditions, and restoring power output
• Changing the extraction pressure or backpressure to balance plant steam flows and maximize efficiency

It’s not a full replacement, but rather a retrofit or engineering redesign that adjusts your turbine’s performance. It’s about bringing your turbine in line with your plant’s current operating realities, not outdated steam conditions from the original plant design. 

But a re-rate doesn’t mean pushing your turbines harder. Sometimes, it’s about working smarter. 

By matching your unit to lower pressures or improved flow, you can cut waste, avoid overengineering, and make sure every cent spent on generating steam counts. 

Re-rates can include any or all of the following:

• Power updates: Increasing the megawatt output
• Flow modifications: Adjusting the steam flow to better match new operating conditions. 
• Efficiency upgrades: Improving heat rate or performance.
• Backpressure modifications: Reconfiguring exhaust pressure for better integration with downstream processes. 

Why should you re-rate?

So when does it make sense to consider a re-rate? 

While every plant is different with specific needs, there are a few common triggers that will spark the conversation of a re-rate. 

Whether it’s steam conditions, changing plant steam demands, or needing more power, a re-rate can be a smart strategic move. 

Here are a few reasons why operators may choose to re-rate:

• Your steam conditions have changed: If you’ve got new boilers,  depleting geothermal wells, or even an upgraded combined cycle gas turbine, your steam turbine might be mismatched– and a re-rate will help get things back on track.
• You’ve got more steam to work with:  When a steam host is lost or a boiler is upgraded, you want to make the most of it. That means re-rating your turbine to handle the increased load.
• Your operations have shifted: Plants often slowly shift their steam loads over time.  Without realizing it, PRVs end up open to cover the flow demands that the turbine can’t handle.  At this point, it’s time to re-rate and stop wasting money through PRVs.
• You want to avoid a full-blown upgrade: When CapEx is tight, re-rates let you extend life and boost output without having to replace the whole unit.

It’s a classic case of fixing your roof while the sun is shining, as smart operators don’t wait until things start to go wrong. Instead, they plan their re-rates in advance so they can make sure they’re getting the best results. 

The engineering behind a re-rate

A re-rate starts with a thermodynamic model and performance simulation. It’s a calculated process that’s rooted in thermodynamics, mechanical insight, and decades of expert field experience. 

Engineers examine every aspect of the unit, from flow dynamics and blading geometry to heat balance and mechanical integrity. 

From there, they redesign the steam path. This might mean:

• New blading and nozzle profiles
• Longer or removed stages
• Upgraded seals
• Machining the case to match redesigned stages
• Adding or removing extractions
• Validating the rotor for new loads   

For more complex re-rates, computational fluid dynamics (CFD), finite element analysis (FEA), or advanced material upgrades might be brought in to handle high stress or thermal variation. 

Why choose EthosEnergy for your re-rate?

As one of the world’s largest independent service providers, we work across OEM platforms to rethink, reimagine, and re-engineer your turbines. 

This means you’re not locked into one manufacturer’s approach. Instead, you get:

• A solution built around you: We don’t go for any cookie-cutter fixes, instead opting for unique performance strategies that fit the specific needs of your plant. 
• Expert input from day one: We use your operating data to design smarter upgrades that perfectly fit your requirements. 
• Speed and quality: EthosEnergy prides itself on its ability to work efficiently and performs both the engineering and manufacturing in-house, giving us full control over the project.
• More value with less hassle: Our re-rates boost output, cut your heat rate, and extend unit life, so you can be confident that your steam turbines are operating at peak efficiency. 
• Installation cost-effectiveness: EthosEnergy can provide as much or as little of the field installation as the customer needs, avoiding subcontractor markups when necessary. If desired, we can offer field services, component manufacturing, and post-upgrade performance validation all under one roof. 

From feasibility studies to final commissioning, EthosEnergy gives you a re-rate that delivers without delays, detours, or high traditional pricing. 

When you re-rate smarter, you run stronger

If your turbine isn’t delivering like it used to, or isn’t built for where your operations are headed in the future, a re-rate could be the strategic move you need. 

At EthosEnergy, we make re-rates work harder for more power, better efficiency, and a future-proofed plant. 

Want to learn more? 

Explore our steam turbine services and let’s start rethinking what your turbine can do.