Rotating Grid Stabilizer Conversion

Provide grid inertia with a synchronous condenser

How renewable energy trends affect grid stability

With the rising adoption of renewable energy, traditional power generation methods are utilized less, and generators are being shut down.

Once these generators are shut down, their role in providing rotational inertia, short circuit power and voltage control, to help balance the grid system disappears with them also. Grid stability is therefore a vital consideration for power plant operators and transmission and distribution network operators, with increasing renewable penetration.

How can Rotating Grid Stabilizers contribute to grid resilience and stability?

How is grid stability maintained?

Traditionally, grid stability is achieved through the dependence on the system strength and system inertia.

System strength refers to the ability of the electricity grid to recover intact from major disturbances and it is provided by the short-circuit power of the generator or synchronous condenser. The same generator also provides system inertia which is critical to maintaining a steady frequency in the grid. And no matter the source of generated power, electrical grid systems rely on both for grid security, safety, and reliability.

In a quest to reduce the carbon footprint, renewable energy sources will continue to be widely adopted. Wind and solar power are non-synchronous and provide no system inertia. It's, therefore, necessary to find solutions to curb the reducing system inertia. 

Interactive map

The need for grid stability solutions is growing

In order to ensure the stability of the grid, there are four key triggers to look out for. Click each icon to see how your region is affected.

*The data is based on preliminary evaluations performed by Siemens Energy and is not meant to be exhaustive.

Convert a generator to a synchronous condenser

With the Rotating Grid Stabilizer (RGS) Conversion solutions, you can repurpose your existing power plant assets to achieve grid stability.

By utilizing power plants that may otherwise become stranded assets, RGS conversions provide necessary system inertia, short circuit power and reactive power to the grid for that balance. 


Inherent frequency response, the result of system inertia, is the ability of an electrical machine to absorb and store or inject energy in order to manage frequency. One way to do this is to use technology with a rotating mass, like flywheels and synchronous condensers, to store energy for short-term frequency support. This helps to prevent blackouts, due to a rapid change of frequency and maintains a stable grid, within its frequency limits. 


 You can also generate additional revenue streams by providing additional active power with our dual-mode turbine solution.

Siemens Energy is helping companies achieve grid stability

Britain’s National Grid ESO launched the Stability Pathfinder program to look for the most cost-effective way to address stability issues in the electricity system. One of the first projects supported by this program was the RGS Conversion project at Uniper’s Killingholme power station in Lincolnshire. Our team repurposed two steam turbine generators into synchronous condensers.


More than synchronous condenser

Your generator can be converted to a Rotating Grid Stabilizer (RGS) in three ways

By spinning continuously, a Rotating Grid Stabilizer provides inertia, dampening fluctuations in the grid frequency. We also offer the hybrid conversion that allows the dual-mode operation to alternate between generation and grid stabilizer modes.

How can a Rotating Grid Stabilizer help you generate new revenue streams while stabilizing the grid?

Watch this webinar recording to find the answers!

What are the benefits of Rotating Grid Stabilizer Conversion (RGS)?

Converting your power plant into a Rotating Grid Stabilizer gives your equipment a second life, saving you from owning stranded assets. Additionally, you can expand your revenue stream with the Hybrid RGS Train Conversion.

Our conversion approach is tailored to meet your needs. Building new infrastructure is one option, but the infrastructure that is already in place can be repurposed as well. Typically, we begin the project with a feasibility assessment to determine whether your assets can be converted to a Rotating Grid Stabilizer (RGS). The next step is to initiate a Front End Engineering Design (FEED) study in order to achieve a successful RGS conversion.


Learn more about our RGS conversion solutions

With our Rotating Grid Stabilizer (RGS) conversion, you can maintain your competitive edge while avoiding stranded assets. Have we piqued your interest? Get in touch with us today to learn more.

FAQ about grid stabilization

Grid stability is what keeps the challenges to power systems, such as the spikes or lulls in demand, power line, or even generator failure, in check. Since power is produced on demand, it's critical to ensure that the power system frequency and voltage remain within normal ranges. Maintaining this balance is necessary to keep the power grid stable and efficient. 

To ensure the grid remains stable and secure, it is essential to balance the electricity grid through frequency stabilization, short circuit power, and voltage control. Flexibility stabilization happens when system inertia responds to sudden load imbalances. The inertia delays the Rate of Change of Frequency (RoCoF), so downstream grid stability controls can be executed. 

Grid inertia is the ability of a power grid to absorb changes in frequency without destabilizing the system. It is the key factor for maintaining grid stability.

Short circuit power contribution is the ability of an electrical machine to inject high levels of current during a grid short circuit event, to ride through the fault and maintain a stable grid. 

Voltage control is the ability to inject and absorb reactive power to ensure a stable system voltage. This helps to reduce the voltage drop caused by the short circuit, limit the short circuit current, and quickly restore the power system's stability. It also enables keeping the system voltage within an acceptable range.