Battery Storage’s Biggest Challenge May No Longer Be Technology, But Market Design

Battery storage market design is becoming one of the defining challenges for Southeast Europe’s energy transition. At Balkan Battery Day 2026, a panel moderated by Michał Motylewski, with Daniel Vlasceanu and Emmanuel Karapidakis, explored how regulation, permitting, grid access and revenue models are evolving alongside battery deployment.

The discussion highlighted an important shift. Building battery projects is no longer simply about securing land, hardware and a grid connection. Success increasingly depends on navigating electricity markets that continue to evolve while projects are being developed.

Battery Storage Is Challenging Traditional Regulation

One of the panel’s recurring themes was that battery storage does not fit neatly into conventional electricity market structures.

Unlike solar and wind generation, batteries can simultaneously behave as generation, consumption and flexibility assets.

According to Emmanuel Karapidakis, this operational complexity has required regulators and transmission system operators to rethink permitting frameworks, balancing market participation and grid connection rules.

In Greece, dedicated regulation for standalone battery storage has only begun to emerge over the past three years, despite discussions around energy storage dating back nearly two decades.

Romania is following a similar trajectory, with standalone storage regulation only recently reaching greater maturity.

The broader conclusion was clear: battery markets are currently evolving faster than regulation itself.

Grid Access Is Becoming More Sophisticated

The discussion also highlighted how the concept of grid access is changing.

Historically, developers focused primarily on whether capacity existed at a given transmission node. Today, the quality and operational flexibility of that connection are becoming equally important.

Daniel Vlasceanu explained that Romanian developers can generally obtain grid access permits, but the commercial outcome increasingly depends on the technical conditions attached to those permits.

These may include:

• grid reinforcement requirements
• curtailment exposure
• operational limitations
• dispatch constraints
• connection sequencing dependencies

As a result, two projects with identical connection capacity may ultimately deliver very different financial performance depending on the operational restrictions imposed by the grid operator.

The panel also discussed the growing importance of dynamic grid management. According to Karapidakis, static substation limits will gradually give way to more intelligent infrastructure capable of managing batteries, renewable generation and demand response simultaneously, allowing existing grid capacity to be used more efficiently.

Revenue Models Are Becoming More Difficult to Predict

While permitting and grid access remain critical, the discussion repeatedly returned to one topic: revenue visibility.

Battery projects generate income from multiple sources, including wholesale electricity markets, balancing services and ancillary services. Predicting how these revenue streams will evolve over time, however, is becoming increasingly difficult.

Karapidakis argued that many current financial models still fail to capture the complexity of real market behaviour.

On paper, batteries appear capable of generating attractive returns through price arbitrage. In practice, actual market dynamics often differ substantially from theoretical assumptions.

As more battery capacity enters the system, competition across balancing markets and arbitrage opportunities is expected to compress revenues further.

This requires operators to continuously optimise participation across multiple markets while adapting to changing system conditions.

Several speakers noted that battery investment increasingly resembles a sophisticated trading business rather than a conventional infrastructure asset.

Battery Optimisation Is Becoming a Game Theory Challenge

One of the panel’s most distinctive observations came when Karapidakis compared battery optimisation to game theory.

Rather than solving purely technical engineering problems, battery operators increasingly compete against other market participants making simultaneous strategic decisions.

Battery performance therefore depends not only on technical specifications but also on:

• competitor behaviour
• balancing market evolution
• storage deployment rates
• transmission system constraints
• changing electricity demand patterns

This makes long-term revenue forecasting considerably more uncertain than in previous renewable technologies.

Capacity Mechanisms Could Play a Larger Role

The discussion concluded with a broader debate about how battery storage should be valued within future electricity markets.

Karapidakis argued that batteries should not be viewed solely as merchant assets competing for trading revenues. Instead, they should increasingly be recognised as critical infrastructure supporting grid stability and energy security.

That distinction has important implications for future market design.

Several speakers pointed to capacity remuneration mechanisms as one possible solution—not as subsidies, but as compensation for providing flexibility and maintaining system reliability.

As electricity systems become increasingly dependent on intermittent renewable generation, flexibility itself is emerging as a strategic resource that markets may need to value more explicitly.

Operational Sophistication Will Define the Next Phase

The panel ultimately described a battery sector entering a much more mature phase.

The industry’s first chapter focused on deployment targets and technology costs. The next chapter will increasingly revolve around market integration, operational sophistication and risk management.

Developers now need to understand not only battery technology, but also grid architecture, balancing markets, optimisation algorithms, regulatory evolution and long-term revenue stacking.

The conclusion was optimistic.

Battery storage is now widely recognised as essential infrastructure for Europe’s energy transition. But as the sector matures, success will depend less on building projects quickly and more on understanding how increasingly complex electricity markets operate in practice.