Europe has built battery storage at remarkable speed over the past few years. In 2025 alone, the continent added a record 27.1 GWh of storage capacity. Germany, Italy and the United Kingdom now account for around 10 GW of Europe’s 66 GW of installed BESS capacity, and the German pipeline is expected to reach 15 GW by 2030. It is a compelling infrastructure story, and one I have followed closely for the better part of a decade.
Capacity is the first metric everyone tracks because it is what gets financed and announced. The metrics that show whether an asset actually performs emerge only once it is running, and that is where much of the market still has a blind spot. The next phase of Europe’s BESS market must now move from scaling up to operational maturity.
The operational reality is harder than it looks
When I sit down with operators across Europe, I hear the same story in almost every conversation, phrased differently each time. They can tell you what their fleet did yesterday, but not why, and not what it will do next month. After years of rapid expansion, many operators now run fleets that mix manufacturers, technology generations and system architectures, and that diversity comes at a cost in complexity. Many run several monitoring platforms, with different data formats and key performance indicators (KPIs) that cannot be compared. This fragmentation slows down day-to-day operations and makes scaling harder.
Our BESS Pros Survey 2026, conducted among more than 100 professionals actively managing these systems, puts some numbers behind these conversations:
- 50 percent of operators struggle with performance and availability problems.
- 41 percent report regular revenue losses due to technical issues.
- 59 percent describe investigating incidents and conducting root-cause analysis as a significant time sink.
These figures show that operational reality is not keeping up with the pace of market expansion.
The reason is straightforward. A 100 MWh system that looks uniform on paper behaves in practice like a patchwork of subsystems. Hundreds or thousands of battery modules each generate dozens of data points and signals. Without the right tools, anomalies go undetected. Operators are paying attention, but with so much data, the signal gets lost in the noise.
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Pure Energie, a Dutch renewable energy company operating its first grid-scale BESS, has experienced this first-hand. Over several months, a state-of-charge imbalance crept in, minor in summer and significant by autumn, and the existing monitoring setup could not catch it. Once proper analytics were in place, the progression was clear in the data. The team could see exactly when the issue started, how it evolved and what was needed to fix it. Instead of fixing problems after the fact, they could now manage performance ahead of time. What stayed with me about Pure Energie’s case is that the imbalance was not hiding. It was visible in the data the whole time. It just was not visible on a dashboard built to track uptime, not degradation. Most of the market, I think, has yet to draw that distinction between data that exists and data that can be read.
The stakes have risen
Over the past two years, the problem has grown, and so has its cost. Revenue streams are more competitive and less forgiving. When a system underperforms or goes offline unexpectedly, operators miss revenue they were counting on. A system delivering 90 percent of its planned output is a financial problem as much as a technical one.
Beyond operations, data has become a financing question. Investors and lenders now scrutinise operational track records before committing to projects. If the data is missing or unreliable, risk premiums go up and bankability suffers. I will go further: within two to three years, I expect operational data quality to matter as much to a financing decision as the technical specifications of the battery itself. Lenders are already asking about it informally in due-diligence calls and site visits. It is only a matter of time before that informal ask becomes a formal requirement in term sheets.
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The consequences are familiar to many operators: lower-than-expected system availability, less usable energy and power, recurring unplanned maintenance and constant back-and-forth with suppliers over unresolved issues. All of these can be addressed, but only if operators can turn system data into reliable insights. This is where the European market is falling short. Operators lack a data structure that moves them beyond basic monitoring towards proactive maintenance.
Data analytics closes the gap
BESS analytics addresses this by turning fragmented raw data into usable insight. It lays the groundwork for detecting technical anomalies early, avoiding unplanned downtime and cutting on-site maintenance. Analytics also gives a far more precise picture of degradation, usable energy and power, safety-related KPIs and performance parameters such as imbalances and thermal trends. Above all, it turns capacity testing from a once-a-year snapshot into a daily or even hourly view, showing operators how much capacity is missing and why. Often the cause is something other than degradation, such as imbalances or state-of-charge (SOC) errors, and these can be fixed. Operators who have that information can recover usable energy, keep asset availability high and plan dispatch and market participation with more confidence.
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Analytics also pays off well beyond operations. Olana, a Finnish utility-scale operator, has found that a clear, historical data log provides leverage well beyond the control room. When the team needs to make a warranty claim, that data log is the proof they bring to the original equipment manufacturer (OEM). By giving insurers clear evidence of monitoring, alarms and historical performance, they have also been able to reduce insurance premiums. Yet most operators still think of analytics as a way to fix problems faster. Olana used it to change the terms of the conversation with people who were not in the control room at all, namely insurers and OEMs. That is the shift I think is underpriced right now. Data is a source of leverage as well as a diagnostic tool.
Collecting more data will not achieve this on its own. The data has to be easy to compare, tracked over time and accessible enough for every stakeholder to use in their daily work.
From building to running
Europe has achieved a great deal in building out storage. The hard work now is running its assets well. If I had to name one habit that will separate the operators who thrive in this next phase from those who do not, it would be this: the good ones track how many hours their team spent on root-cause analysis for their last five incidents. Most operators cannot answer that yet. That is the number I would start with.
Construction sites delivered the first phase of Europe’s storage build-out. The next will be won in control rooms, with the right work orders, smart dashboards and trusted data pipelines. (Stephan Rohr/hcn)
