Wind turbines do offer some inertia capabilities. Fixed speed wind turbines provide real passive inertia as the rotating element of the turbine is directly coupled with the grid. However, the magnitude of this inertia per unit capacity is significantly less than of that of a traditional power plant synchronous generator with a much lower inertia constant. Most modern wind turbines are variable speed, either doubly fed induction generator type or full converter type. In both cases, the wind turbine is decoupled from the grid and utilises power electronics.
The power electronics can provide synthetic inertia, however unlike a fixed speed wind turbine this would be active inertia which has some inherent delay, as this is implemented using sophisticated control methods within the power electronic systems. By using control techniques to provide synthetic inertia, there is a benefit of further flexibility on the wind turbines response during a frequency event. However, with this flexibility comes the challenge of coordinating the response of multiple wind turbines to ensure system stability.
Solar photovoltaic systems do not have any rotating components that can provide inertia. Some advanced modern inverters within solar photovoltaic systems can provide synthetic inertia by adjusting their power output in response to frequency changes. However, this can only be achieved if the solar farm providing the energy is somewhat curtailed and will only provide a small amount of inertia with a very low inertia constant. This approach to leaving reserve capacity on solar farms is uneconomical and could lead to increased levelized cost of energy for the solar farm with little frequency support.
So, in general, yes, renewable energy can provide inertia to the grid, but significantly less in comparison to traditional power plant synchronous generators.
How can we ensure sufficient grid inertia with high renewable penetration?
Utility scale battery energy storage facilities can offer fast acting frequency response services to help manage frequency events on the grid either at the transmission or distribution level. These facilities have the capability to absorb and deliver energy in milliseconds of an event. However, this comes with some challenges. Firstly, having sufficient capacity on the grid to connect such systems is a rising concern with grid constraints becoming increasingly common. Secondly, managing these facilities as they are distributed across the grid becomes a complex challenge. Furthermore, although milliseconds is a fast response, it is not instantaneous like the response of a synchronous generator.
This means as we reduce the natural instantaneous inertia on the grid, the rate of change of frequency (RoCoF) during a frequency disturbance event will be increased until the battery storage systems respond. If the RoCoF is too high, there is the potential that protection systems may trip and inhibit the response of the battery energy storage system before it comes online. A further challenge with respect to protection schemes as we increase the battery energy storage capacity on the grid is fault level, as these systems have much lower fault level contribution compared to synchronous generators. If the fault level of the grid is low due to high battery energy storage system penetration, there is the potential that faults may not be detected by overcurrent and distance protection schemes with the possibility of severe and prolonged voltage disturbances on the network. Having to install these facilities also comes at a cost, so the levelized cost of energy for renewables suddenly looks much higher when considering these systems are required in conjunction.
Synchronous condensers are large synchronous generators with rotating mass that can also help support the grid in managing the system frequency by providing reactive power and inertia into the grid. For maximum effectiveness in providing inertia during a frequency disturbance event a synchronous condenser must be located near to the disturbance. They are also disadvantaged in that their response cannot be controlled, giving grid operators less flexibility in the controlling of inertia response. As traditional power plant generators come offline, there is the potential for the synchronous generator of the system to be re-purposed as a synchronous condenser, giving the plant a second life. Again, these systems come at a cost further increasing the cost of integrating renewable energy on the grid.
Demand side management is another tool which helps reduce the amount of inertia needed on the grid by reducing load during frequency disturbance events.
Other technologies such as super capacitors can also help support the frequency of the grid, providing an ultra-fast response. However, these technologies are considered expensive.
Can microgrids help support grid inertia?
Microgrids are localised energy systems comprising of various generation technologies which generate, distribute and manage energy independently with or without a grid connection. Large energy consumers such as data centres can help support the grid by implementing microgrids. This support could be via demand side management, decoupling the micro grid from the grid to create an islanded system. On the other hand, the micro grid can provide support with the addition of grid forming inverters, synchronous generators and battery energy storage systems, to enhance the grid during frequency disturbance events. Although, this does not provide substantial inertia in comparison to traditional power plants, it does contain the required technology to effectively support the grid. These services can provide an additional source of income to the micro grid operator.
Conclusions
As the presence of renewable energy technologies continue to rise on grids, the necessity to increase the inertia on the grid is essential to ensure the stability of our energy supply. Historically, traditional power plant synchronous generation has provided substantial inertia to the grid, ensuring stability during frequency disturbances. However, as wind and solar penetration has increased, the grids inertia has been significantly reduced.
There are potential solutions to increase the grids resilience to frequency disturbance events, however finding the optimum solution is a complex problem with significant control system co-ordination and response challenges. All potential solutions come at a cost which will ultimately result in increased energy bills. This leads to the question of do we need to take our foot off the pedal on the rapid deployment of renewable energy schemes and focus on grid enhancement and stability? Also, should critical power industries such as hospitals and data centres consider microgrids to reduce their exposure to the stability risk of the grid?
AVK has extensive experience supporting data centre operators in enhancing energy resilience through advanced on-site power solutions, including grid-forming systems and microgrids. Our teams work end-to-end—from early feasibility studies to detailed design, commissioning, and operational support—to help developers and operators navigate the complexities of grid stability and inertia in a high-renewables future.
As the energy landscape evolves, on-site power is no longer just a backup—it’s a critical tool to safeguard operations and support the wider grid. With AVK’s expertise, data centres can play an active role in stabilising tomorrow’s energy systems.
