Reliability May Become the Most Undervalued Factor in Battery Storage

Battery storage reliability is becoming an increasingly important topic as Europe’s energy storage market matures. At Balkan Battery Day 2026, Luca Pasqualini’s presentation, “Reliability Redefined”, shifted attention away from deployment volumes and battery capacity toward a question that developers, operators and investors are beginning to ask more frequently: how do you ensure a battery system remains operationally reliable over 10, 15 or even 20 years?

According to the presentation, the answer may depend as much on service structure, operational support and long-term partnerships as on the battery hardware itself.

The Industry Is Moving Beyond Deployment Metrics

Battery storage markets across Europe continue to expand rapidly, but the conversation is evolving.

Early market growth was driven by deployment targets, CAPEX reductions and improvements in energy density. While those factors remain important, operators are now beginning to experience the operational realities of managing large-scale battery assets.

As Pasqualini noted, every battery project eventually encounters failures, operational disruptions and maintenance challenges.

The critical issue is not whether problems occur, but how effectively they are managed throughout the asset lifecycle.

This distinction matters because battery systems are not passive infrastructure. They are highly active operational assets interacting continuously with grid conditions, software platforms, market signals and thermal management systems.

In practice, reliability is increasingly becoming an operational strategy rather than simply a technical specification.

Why the Bathtub Curve Matters

One of the most practical concepts introduced during the presentation was the “bathtub curve”, a reliability model commonly used across engineering industries.

The model illustrates how failure rates typically evolve throughout the lifecycle of a technology.

Problems tend to cluster during two key periods:

• the early commissioning phase
• the late wear-out phase near end of life

Between these periods, systems often operate relatively consistently.

For battery storage developers and operators, this has important implications.

Early-stage failures may result from site integration challenges, configuration mismatches, software interactions or operational unfamiliarity. Later in the lifecycle, degradation, component fatigue and ageing infrastructure introduce a different set of operational risks.

The presentation highlighted that long-term project economics are heavily influenced by how these two critical phases are managed.

Reliability, therefore, is not simply about technology quality. It is about operational preparedness.

Service Models Are Becoming Strategically Important

Another major theme of the presentation was the growing importance of after-sales support within the battery storage sector.

As storage systems become larger and more integrated into critical energy infrastructure, response times, monitoring capabilities and local technical expertise become increasingly valuable.

LONGi ESS outlined an approach focused on proactive monitoring, local engineering partnerships and rapid response capabilities.

This reflects a broader trend visible across the industry.

Battery projects are no longer assessed solely on equipment costs. Operators increasingly evaluate:

• monitoring systems
• EMS and BMS integration
• local technical support availability
• incident response capability
• spare parts strategies
• long-term supplier stability

These factors directly influence operational uptime, maintenance costs and project bankability.

The issue becomes even more important as battery assets participate simultaneously across multiple electricity markets, where downtime can immediately impact revenues.

Bankability Is Expanding Beyond Finance

The presentation also explored an increasingly important concept within Europe’s storage sector: bankability.

Historically, bankability referred primarily to financial stability and access to project financing. In battery storage, that definition is broadening.

Developers and investors increasingly want confidence that suppliers will remain both operationally and financially capable of supporting projects throughout their full lifecycle.

This is particularly important in a sector where technology evolves rapidly and many market participants still have limited long-term operating track records.

Pasqualini argued that developers should evaluate not only product specifications, but also whether suppliers are likely to remain active and capable of supporting systems 15 or 20 years into the future.

As competition intensifies and market consolidation accelerates, this consideration is becoming increasingly relevant.

Europe Is Entering an Operational Maturity Phase

The presentation reflected a broader shift taking place across the battery industry.

The sector is gradually moving from deployment expansion toward operational maturity.

Future competitiveness may depend less on who can manufacture larger batteries and more on who can operate them reliably, support them effectively and maintain performance throughout increasingly long project lifecycles.

This is especially relevant in Europe, where battery systems are expected to become critical infrastructure supporting renewable integration, balancing services and grid resilience.

As operators begin managing fleets of utility-scale battery systems across multiple markets, reliability is becoming a commercial issue as much as an engineering one.

In a market where revenues increasingly depend on continuous optimisation and market participation, even relatively small operational disruptions can have significant financial consequences.

The message from LONGi ESS was straightforward: the industry may still be focused on growth, but the next phase of the market is likely to reward those capable of delivering stability over time.