Rotating Grid Stabilizer Conversion Solutions

Keep it Spinning

We cannot be caught blind sighted. As the share of renewables share continues to grow, grid stability is at riskWhy? With more wind and solar power, less rotating masses of turbines spin in fossil power plants. And with fewer of these providing system inertia, grid frequency is threatened. In turn, the risk of black-outs due to fast frequency and voltage drops increases. So, while it is good fossil power plants stop emitting greenhouse gases, we need their inertia.


Luckily, there is a solution for that: Rotating Grid Stabilizer Conversion Solutions (RGS) for existing power plants. They provide necessary system inertia to the grid – and that’s why today, we’re witnessing a renaissance of RGS solutions throughout the world. And what better place to do that than in power plants that may otherwise become stranded assets. This way, the share of renewables can continue to rise – and black-outs don’t threaten us any longer. Beyond this, rotating grid stabilizer conversions is a repurposing approach to give existing plants threated by shutdown a second life option with new revenue streams among others within the brownfield transformation decarb journey.

Power transmission used to be a linear chain – electricity got distributed from a centralized fossil fired power plant based on power demand to a network of consumers. But with its high greenhouse emissions it is not a viable model for the future.

Today, the grid is changing to a complex network of distributed power generation and consumption with a rising share of renewables and other smaller power infeed sources that goes hand in hand with a decreasing share of rotating mass that turbine trains used to supply.

Increased share of renewables requires new grid control and stabilization equipment

Brownfield Transformation: Building a bridge to a new energy future

Here’s a power plant. There’s the decarbonized future we aim for. Check our new white paper to explore the options to repurpose existing plants to achieve our goals.

Rotating grid stabilizer free webinar by Siemens Energy

Webinar: Brownfield Transformation – A decarbonization journey for your power assets

A Brownfield Rotating Grid Stabilizer conversion not only enables a rising share of renewable infeed on the grid but also provides a significantly reduced carbon footprint compared to a new build. Watch our webinar recording to learn more!


Potential Benefits

Compared to RGS greenfield projects, the brownfield transformation approach has various benefits.

No matter whether you choose to build new RGS solution as a greenfield approach or reuse existing infrastructure in a brownfield conversion approach, each strategy has its own advantages. In consultation with our experts, you can choose which option suits you best. Now, if you choose a brownfield RGS conversion, there are several obvious advantages like significantly shorter lead time and reduced Capex due to the possibility to reuse existing plant assets, grid connection and permits.

Do you want to learn more about Siemens Energy greenfield grid stabilization solutions?​

Interactive map

Growing potential for RGS conversions worldwide

Interactive map to check wheater typical trigger for a need of rotating grid stability services are valid in your region. Klick on the colored buttons to find out more:

The data is based on preliminary evaluations performed by Siemens Energy without being claimed to be exhaustive.


What is the best solution for you?

We provide turnkey Rotating Grid Stabilization Conversion Solutions – based on broad experience, all tailored to your specific needs.

The combination out of both worlds, providing active and reactive power as dual mode, having the flexibility to serve the power and grid stability market with the very same power plant is our so called “hybrid solution”. Here a self-synchronizing clutch connects and reconnects the turbine from the generator depending on the actual grid demands. 


Whereas a typical RGS system consists of a synchronous generator permanently synchronized with the grid. In order to increase the rotating mass and thus system inertia a flywheel can be added. The rotating mass stores kinetic energy. Then, as soon as the grid frequency changes, the RGS responds, stabilizing the grid frequency. In the same fashion, it supplies short circuit power as well as reactive power compensation for voltage control, all being key parameters for grid stability.

Turning concepts into reality

Grid Stability Conversion Projects around the world

It’s clear that as rotating mass from fossil fired power plants goes off-line, the need for grid stability services such as RGS conversions increases as well.

Today, we see this particularly happening in Europe. There, you find a perfect combination of a fierce political push concerning the energy transition, the wish to repurpose many sites of fossil power plants, and a deep and rich expertise by companies such as Siemens Energy to undertake such projects.

Grid stability running engagements

Running Engagements located in many countries: Siemens Energy has a large track record of Basic, Hybrid as well as RGS conversions with Flywheel implementations. Our Technical Consultancy Services (TCS) approach is the key to define an optimized tailor made solution which fulfills your demands: We typically start the project with a RGS Feasibility Assessment. As a next step we step into the phase of a Front End Engineering Design (FEED) study as Basis together to achieve a successful Rotating Grid Stabilizer conversion project.


Grid stability is in any nation’s interest in order to keep its economy running and its people safe. And that’s why Britain’s National Grid ESO (Electricity System Operator) pursues a Stability Pathfinder program to ensure its grid stays stable despite of declining synchronous energy generation. One of the first projects to be realized can be found at Killingholme in Lincolnshire, where the global energy company Uniper has two steam turbine generators repurposed by Siemens Energy to enable synchronous condenser operation. 


How to achieve grid stability?

Grid Stability can be defined by 3 major parameters:

Frequency Stabilization

Response: instantaneous - milliseconds

  • System inertia inherently responses to sudden load imbalances
  • System inertia delays the Rate of Change of Frequency (RoCoF) so downstream grid stability controls can execute
  • Inherent system Inertia can be increased by SynCons & Flywheels

Short Circuit Power

Response: instantaneous - milliseconds

  • Indicator for Grid Fault to execute downstream stability controls
  • Short Circuit Contribution ensures power system resilience

Voltage Control

Response: milliseconds - seconds

  • Reactive Power Compensation for Voltage Stability and Load Flow control

Peaked your interest?

If you have any questions, or if you'd like to learn more about our Rotating Grid Stabilizer solutions, please send us a message.