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

Energy storage is rapidly reshaping balancing markets across Europe. At Energy Week Black Sea 2026, discussions highlighted how storage is no longer limited to utility-scale batteries but increasingly includes distributed and residential flexibility.

Grid-Scale Batteries Enter the Mainstream

At the transmission and distribution level, Alexandru Chiriță, CEO of Electrica, outlined how battery storage is becoming embedded across the power system.

Romania is targeting more than 1 GWh of installed battery capacity in the near term, while market expectations point toward 5–6 GWh within the next 18 months if current projects move forward as planned.

By 2030, overall storage needs could reach 10–20 GW, reflecting the growing role of storage in stabilising renewable-heavy power systems.

Battery projects are attractive partly because they are comparatively fast to deploy. Unlike new transmission lines, batteries can be installed quickly once permitting and grid access are secured.

However, regulatory timelines remain a bottleneck. According to Tatiana Fiodorov of Fiodorov & Partners, even standalone battery projects can take up to two years to secure permits despite their limited land footprint and technical simplicity.

Residential Storage and Aggregated Flexibility

Alongside grid-scale batteries, residential storage is emerging as a new flexibility resource.

Jan Hicl of Delta Green presented a real-world example of residential batteries providing system services. By aggregating approximately 300 households equipped with batteries, EVs and solar PV, Delta Green successfully delivered aFRR services to the Czech TSO, with revenues distributed directly to participating consumers.

This model demonstrates how distributed storage can contribute directly to balancing markets.

Unlocking Flexibility Already Inside the System

Decentralised storage models address several systemic challenges simultaneously. They reduce reliance on expensive peaking assets, lower balancing costs and activate flexibility already present within the power system.

In Romania alone, grid balancing costs reached approximately 5 billion lei, driven partly by rapid solar deployment and limited control of prosumer output.

Delta Green’s analysis suggests that an average household equipped with a battery, EV and PV system could generate up to 12,000 lei per year by participating in energy and balancing markets.

When aggregated at scale, residential flexibility could exceed industrial flexibility potential by six to seven times.

Storage as a System-Level Solution

What connects grid-scale batteries and household storage is their ability to restore controllability in increasingly decentralised energy systems.

As renewable penetration rises, the ability to store, shift and modulate electricity becomes as valuable as generation itself.

Across the Balkans and South-East Europe, energy storage is no longer a single technology category. Instead, it is becoming a spectrum of solutions, from GW-scale batteries to virtual power plants built from everyday homes.

Together, these technologies contribute to a common objective: maintaining reliable and flexible energy systems while the energy transition accelerates.