energy storage

Maximizing Grid Stability: How Supercapacitors are Shaping the Future of E-STATCOM

In the domain of power transmission and distribution, the integration of renewable energy sources has prompted the development of more sophisticated grid stabilization technologies. One such advancement is the Enhanced Static Synchronous Compensator or E-STATCOM, a complex electrical installation in the Transmission System Operator (TSO) power grid to compensate for short-term load fluctuations and provide the grid with inertial response by employing energy storage systems to absorb and supply short bursts of high active power. 

Features of E-STATCOM: 

  • Fast voltage frequency support
  • Synthetic Inertia
  • Fault current generation
  • System Strength Support Capabilities
  • Grid-forming control
  • Scalable energy storage capacity in the hundreds of MWs 

E-STATCOM installations are substantial in size, even spanning the equivalent of a football field. Alongside the energy storage unit, E-STATCOMs incorporate various components such as High-Voltage AC transformers, AC/DC converters, AC circuit breakers, disconnectors, earthing switches, instrument transformers, control rooms, protection and monitoring systems. They also accommodate auxiliary systems like cooling devices. 
Optimizing Energy Grids with Supercapacitors 
Given the oscillating operation profile and fluctuating demands of the grid, supercapacitors are an unparalleled energy storage technology for E-STATCOMs. Other relevant energy storage technologies suffer from low efficiency, low versatility, high maintenance, large footprint, problematic life time and/or impose safety concerns. Supercapacitors, on the other hand, offer high power and efficiency, long cycle life, low maintenance, and importantly, no risk of thermal runaway—an exothermic uncontrolled reaction that occurs in Li-ion batteries, particularly concerning when dealing with high voltage. A supercapacitor-based energy storage solution has a significantly smaller footprint and cost compared to battery solutions with the same rated power. Furthermore, it can be easily customizable according to future needs thanks to its modular structure – with supercapacitors, there will be no need to redesign the solution if the power rating changes. 
An E-STATCOM can generate any desired voltage shape. Need voltage regulation? The energy storage remains idle, and the inverter alone can handle the task. Need frequency regulation, blackout prevention, or damping grid disturbances? Supercapacitors are always ready, perpetually connected, and capable of “emulating” any machine on the grid. They offer the benefits of spinning generators without their disadvantages. such as emissions. The grid stabilization characteristics achieved without the use of a rotating mass are the reasons why the application that supercapacitors are addressing is called “virtual inertia”. 
Supercapacitors and SkelGrid 2.0 

SkelGrid 2.0 is engineered to raise the bar for power management in infrastructure environments, addressing the need for short-term backup power and enhanced power quality. Its modular architecture allows for tailored configurations to meet the diverse requirements of our customers, ranging from compact, space-efficient setups to extensive container-sized systems capable of delivering power at the megawatt level. Traditionally, generating three megawatts of power brings to mind large containers filled with batteries. However, SkelGrid 2.0 disrupts this perception by achieving such significant power output from a single 19-inch rack unit, occupying just slightly more than a quarter of a square meter. Considering the expansive size of E-STATCOM, using batteries for active power supply is not feasible due to their footprint. 


  • Impressive Power Density: 3MW in a single cabinet.
  • 15+ Years Lifetime: With minimal impact on efficiency after one million cycles.
  • Field-tested: Over 10,000 installed modules and systems, covering applications in grid, transportation, and industry.
  • Easy integration: Connects directly to DC bus system, DC-DC converter, or AC bus system through DC-AC inverter.
  • Advanced CMS: The market’s most advanced Capacitor Management System (CMS) with numerous functions, including resistive balancing, State-of-Health estimation, and prediction of remaining useful life.
  • Made in Germany: Utilizing a sustainable European supply chain for materials, components, and production. 

Roundtrip efficiency is a critical measure of an energy storage system's performance, quantifying the usable energy returned as a percentage of the energy initially stored. Notably, supercapacitors boast up to 99% efficiency, enabling SkelGrid 2.0 to utilize nearly all stored energy with minimal losses. This efficiency is important for enhancing operational cost-effectiveness and minimizing environmental impacts across various applications. 

The reduced internal resistance of supercapacitors translates to lower energy dissipation as heat. This decrease in heat production is important for maintaining the integrity of system components and prolonging the operational lifespan of the system. In scenarios involving 300, 400, or 500 energy storage cabinets, managing heat can pose a significant challenge. However, with SkelGrid 2.0, this concern is already mitigated. 

Expanding on its technical superiority, with the SkelGrid 2.0, Skeleton Technologies offers a system developed to address critical infrastructure projects, contained within a fully European value chain.

Best energy storage solutions with


Ready to revolutionize your energy strategy? Our experts are at your service, offering personalized guidance to navigate the complex world of energy storage. Discover how our solutions can power your success.

Connect with an expert now

Ready to become energy storage expert? Join our newsletter!