From Grid-Scale Batteries to Household Flexibility: Storage Reshapes Balancing Markets

Battery energy storage infrastructure is becoming a defining element of power system design across South-East Europe. What was once treated as a project-level optimisation tool is now increasingly recognised as a system-level solution.

Across the region, this transition reflects a deeper shift in how power systems are being redesigned under pressure from renewables, volatility and geopolitical risk.

From Assets to Infrastructure

Historically, infrastructure meant grids, pipelines and power plants. Batteries sat outside this definition, treated as merchant assets or ancillary technologies.

That distinction is now breaking down.

As balancing costs rise, congestion intensifies and interconnectors reach their limits, storage is increasingly performing core system functions traditionally delivered by networks and thermal generation.

Storage as a System Function

Evidence from across South-East Europe points clearly to this shift.

Battery storage is now being deployed to stabilise weak grids, absorb renewable surpluses, manage congestion and reduce the need for emergency interventions.

In several markets, storage is already lowering system-wide imbalance costs, effectively acting as virtual transmission capacity.

A New Framework for Investment and Regulation

This reclassification has major implications.

Infrastructure assets are planned, regulated and financed differently from merchant projects. They prioritise reliability, system value and long-term cost reduction over short-term arbitrage.

As regulators and TSOs begin to recognise the structural role of storage, new models are emerging that combine market revenues with system service contracts and public support.

A Faster Path to System Stability

For the Balkans, this evolution is particularly important.

Grid expansion timelines remain long, permitting is complex and cross-border capacity is constrained. Battery energy storage infrastructure offers a faster, modular alternative that can be deployed where and when system stress appears.

The key question is no longer whether storage belongs in the system, but how quickly policy and regulation can align with its real function.

From Deployment to System Design

Balkan Battery Day sits at this inflection point.

The conversation is moving beyond individual projects toward system architecture, and batteries are increasingly at the centre of that design.