The issue of grid stability is becoming critical as the energy landscape transforms. A recent report by the US Department of Energy (DoE) highlights the potential for a drastic increase in power outages, warning that blackouts could increase by 100 times in 2030 if the US continues to retire 104GW of reliable power sources while also failing to add additional firm capacity.[i]
The report goes on to suggest that outage hours could rise to more than 800 hours per year, putting millions of households and businesses at risk of blackouts. In a foreshadowing of these risks, in June of 2025 the DoE was forced to issue an emergency order to address potential electricity shortages in the southeastern US. It was caused by surging in demand in response to extreme weather conditions across the country.[ii]
The situation is exacerbated by rising electricity demand, driven by the electrification of transport and heating, as well as the increasing use of AI. The rapid growth of data center electricity consumption is set to more than double to around 945 TWh by 2030, according to a special report by the IEA, published in April.[iii]
According to GlobalData, the global power mix in electricity generation will, over the next ten years, be driven primarily by sustainable and renewable energy sources. Reliance on fossil fuels will continue to decline, due to both regulatory pressures and the advantages of alternative energy sources. In Europe, many countries such as the UK, France, Germany, Poland and Spain already have targets to decommission coal plants from 2024.[iv]
The Middle East and Africa are forecasted to decarbonize most slowly, with thermal power still contributing to 73% of its power mix by 2035. The Middle East’s economic reliance on fossil fuels, and Africa’s need for affordable energy, are the driving factors. Thermal power will also continue to play a key role in Asia-Pacific’s power mix in 2035, accounting for a 47% share. Contrastingly, South and Central America will have a much cleaner energy mix, driven by a strong base of hydropower generation (50% share of its power mix in 2024) and supplemented by increasing solar PV and wind generation.[v]
Growing reliance on renewables, while beneficial for reducing carbon emissions, creates a supply-demand imbalance that grid operators must manage. The intermittent nature of renewable energy means that there are times when power generation does not meet demand, especially during unfavorable weather conditions. The transition to a more renewable-based power grid presents significant challenges that must be met head on.
Challenges to grid stability
Rising electricity demand and deeper renewable integration are straining grid infrastructure. Existing grids, primarily designed for centralized power generation, are being pushed to their limits. This necessitates investments in grid modernization, including the development of smart grids, advanced metering infrastructure and demand-side management systems. As the grid evolves, it faces several challenges.
First, reduced inertia. Traditional power plants, particularly those based on fossil fuels, provide a crucial stabilizing effect – inertia. This inertia helps maintain the grid’s frequency during fluctuations in supply and demand. However, as these plants are retired in favor of renewable energy sources, which typically do not provide the same level of inertia, the grid becomes more susceptible to voltage fluctuations and instability. In regions with high penetration of renewables, such as the EU and California, the absence of sufficient inertia has led to incidents of frequency instability that could result in outages if not managed correctly.
Second, weaker voltage control. The integration of variable renewable energy sources, like wind and solar, complicates voltage control. These energy sources are inherently intermittent, and output can fluctuate significantly due to weather conditions or time of day. This variability makes it challenging to maintain consistent voltage levels across the grid. Without adequate voltage regulation, power quality can suffer, leading to outages. Advanced technologies, such as power transformers with monitoring systems, are necessary to manage these fluctuations effectively.
Third, growing instability: The shift towards decentralized energy resources and bidirectional power flows introduces additional complexity into electric distribution networks. As more households install solar panels and battery storage systems, the flow of electricity can become unpredictable. Power grid operators must implement sophisticated grid management technologies to handle these new dynamics effectively. The National Renewable Energy Laboratory (NREL) has noted that existing distribution infrastructure in some areas may lack capacity to manage increased power flow from these distributed generation sources, further exacerbating stability issues.[vi]
The transition to a more renewable-based power grid presents significant challenges, requiring innovative solutions, as well as upgrades to existing infrastructure, to ensure reliable and stable electricity delivery.
Groundbreaking solutions
To address the challenges faced by power grids, plant owners are turning to a diverse portfolio of solutions. These include converting existing turbines into synchronous condensers, deployment of Flexible AC Transmission Systems (FACTS), High Voltage Direct Current (HVDC) systems, and digital automation. Each of these technologies plays a crucial role in enhancing grid stability, flexibility and the longevity of existing infrastructure.
Rotating Grid Stabilizer conversion (RGS), a Siemens Energy innovation, represents an easy-to-implement and practical solution to the complex challenges of integrating renewable energy sources into power grids. Mechanical devices help maintain grid stability by providing inertia, able to absorb and release energy quickly, which helps in balancing supply and demand fluctuations. This is particularly useful in grids with a high penetration of renewable energy sources, which can be intermittent. These systems can maintain grid frequency and voltage without traditional power generation constraints. The technology offers a transformative approach, allowing existing power infrastructure to be adapted rather than completely replaced.
Flexible AC Transmission Systems (FACTS) increase the reliability of AC grids by ensuring stability and boosting transmission efficiency. FACTS are generally power electronics-based systems that can quickly respond to changes in the grid, thus improving the reliability and efficiency of power transmission. Modular, customizable and flexible, AC transmission systems provide a solution to high voltage fluctuations, preventing power failures. Additionally, network assets can be optimally utilized, and load-induced disturbances mitigated.
High-voltage direct current (HVDC) transmission systems are becoming increasingly important in a global energy landscape characterized by rising digitalization, accelerated decarbonization and the unprecedented uptake of distributed energy resources. HVDC cables, for instance, provide a more efficient means of transmitting electricity over long distances compared to traditional AC cables. They are particularly useful for subsea power transmission, where they can connect offshore wind farms to onshore grids, facilitating the integration of renewable power resources and stabilizing the grid, alongside FACTS and energy storage solutions.
Digital automation involves the use of advanced technologies such as smart meters, SCADA systems (for monitoring automated processes) and Ethernet switches to enhance grid operations. These technologies enable real-time monitoring and control of the grid, allowing for more efficient management of electricity distribution and consumption.
By integrating these technologies, power plant operators can not only bring balance back to the grid but also ensure power systems are more resilient, efficient and capable of meeting future energy demands.
Siemens Energy: Experts in energy transition
The transition to a more renewable-focused energy grid presents both opportunities and challenges, but the DOE’s warning underscores the urgency of addressing grid stability within the next decade. The integration of innovative solutions such as FACTS and HVDC transmission systems, alongside comprehensive digital automation and improved grid management technologies, will be essential to ensure a reliable and resilient power supply for the future, and for keeping the lights on.
Siemens Energy is at the forefront of this effort. For example, when a gas plant is slated for retirement, its rotating generators can still provide grid stability services if decoupled from continuous power generation by utilizing a Siemens Energy Rotating Grid Stabilizer (RGS) conversion. This turns a conventional generator into a synchronous condenser with optional flywheel attachments, enabling it to act as a stabilizer for the grid without burning fuel. As Siemens Energy’s RGS conversion solutions range from basic conversions, using existing turbine-generators with minimal changes, to enhanced versions with flywheels for maximum inertia and dual-mode operation, it highlights how RGS can open up new business models for gas plant owners as grid support. And there are solutions for plants still operating too; hybrid conversions provide maximum flexibility via dual-mode operation, alternating between power generation mode and grid stabilization mode. They are perfect for plant owners looking to expand revenue streams by providing grid services.
Increasing electricity demand and integration of renewable energy sources are significant trends impacting the power industry, requiring substantial investments in grid infrastructure and technology to ensure a reliable and sustainable future. The focus on smart grid projects and modernization efforts is crucial to addressing these challenges and supporting the transition to a more resilient and efficient energy system.
Download the whitepaper below to learn more about Siemens Energy’s grid stability solutions.
[i] https://www.energy.gov/articles/department-energy-releases-report-evaluating-us-grid-reliability-and-security
[ii] https://www.energy.gov/articles/secretary-wright-issues-emergency-order-secure-southeast-power-grid-amid-heat-wave
[iii] https://www.iea.org/reports/energy-and-ai
[iv] GlobalData: Key Power Sector Trends and Outlook, December 2024
[v] GlobalData: Global Power Mix in Transition 2022 – 2035, May 2025
[vi] https://docs.nrel.gov/docs/fy16osti/65331.pdf
