In many regions, modern grids and power systems are dominated by power electronics with a reduced role for synchronous machines; they are therefore affected by increasing stability and reliability problems. In addition, large loads such as data centres and electrolyser plants are connected to the grid via power converters, and often they operate as non-programmable loads, harming grid stability.

Synchronous Condensers (SynConds) provide an effective and largely proven solution for enhancing grid robustness by supplying voltage regulation, reactive power support, short‑circuit power, and rotational inertia. They contribute to improved voltage quality, optimised power‑factor control, and enhanced system reliability.

Hybrid System for additional grid services

The ongoing evolution of national grid codes and electricity market frameworks is creating new opportunities for hybrid power systems, in which multiple generation technologies, such as inverter-based renewable (IBR) energy sources and conventional synchronous units, are integrated.

The presented project is based on a hybrid energy‑storage architecture that combines a SynCond with a Battery Energy Storage System (BESS), adopting a Grid-Forming Inverter. The synchronous condenser, coupled to a flywheel, enables the provision of stored rotational inertia, utilised to dampen frequency deviations and reinforce overall grid stability.

In parallel, the BESS is designed to store excess active power, for instance generated from renewables (RES), and discharge it when required. The combined deployment of these two technologies enhances the reliability and operational flexibility of power systems.

The two components, SynCond and BESS, are integrated and optimally managed by an in-house developed Smart Integrated Control tool (Plant Integrator). The hybrid system delivers significant advantages in the provision of grid‑support services, such as frequency and voltage control.

In combination, these technologies enhance system stability by increasing short‑circuit strength, improving frequency support, augmenting overall system inertia, reducing the rate of change of frequency (ROCOF), and enabling precise reactive‑power regulation. Furthermore, the hybrid configuration is capable of supplying black‑start functionality, further strengthening grid resilience.

Economic analysis and business case

An economic profitability analysis has been performed to evaluate the business case for the deployment of the hybrid system in the German grid scenario, where RES role is quite relevant, and a new inertia market is starting in 2026 (momentanreserve).

The combined SynCond and BESS optimise, in addition, the CAPEX by sharing part of the plant's electrical items. The hybrid system is able to catch larger revenue streams by providing the grid with a wider portfolio of services. This scenario reduces the business risk and increases the project's bankability.

Conclusion

The future of the Synchronous Condenser market looks promising, driven by the increasing integration of renewable energy sources and the need for grid stability. As countries worldwide continue to transition towards cleaner energy, the demand for Synchronous Condensers is expected to grow. These machines will play a crucial role in ensuring the reliability and stability of power grids, supporting the seamless integration of renewable energy.