TECH

The new race for batteries could completely change how the power grid operates

Europe’s energy transition is creating a power grid increasingly dependent on a technology that, until recently, seemed to be merely part of the solution. Thousands of batteries already store electricity generated from renewable sources, helping to balance periods of surplus and shortage. However, as these systems multiply, a counterintuitive situation arises: under certain circumstances, they could all act simultaneously, placing additional strain on the grid precisely when it needs stability most.

The growth of solar and wind power has raised an issue that cannot be resolved simply by installing more panels and turbines. The sun does not generate electricity throughout the night, while the wind can die down just as demand rises.

This is where battery energy storage systems—known as BESS—come into play.

During periods of high output, these batteries can absorb and store surplus electricity. When consumption rises or renewable generation drops, they can feed some of that energy back into the grid.

This expansion is already proceeding at a rapid pace. In 2025, Europe added approximately 36 GWh of new capacity—a 48% increase over the previous year. With this, the continent surpassed the 100 GWh mark for operational storage capacity for the first time.

More than half of the new installations that year consisted of large-scale projects connected directly to the power grid.

The advantage is clear. Storing surplus energy allows for greater utilization of power generated from renewable sources and reduces instances where electricity availability is so high that prices turn negative.

According to estimates by Ember, by 2030, European solar and wind generation could exceed domestic demand during certain periods, accumulating a surplus of up to 183 TWh over the course of a year.

This scenario could lead to significant savings, including a reduced need to purchase gas to meet demand. However, an issue arises precisely when these batteries move from being few in number to existing by the thousands.

The most critical moment may be precisely when the grid calls for help... The warning came from the United Kingdom, where the Panel of Technical Experts—a body that reviews analyses regarding electricity supply security—examined a specific situation involving batteries participating in the capacity market.

Imagine grid operators realizing that electricity supplies might run tight. Before that happens, a warning known as a "Capacity Market Notice" may be issued.

For certain batteries, this notice serves as a crucial signal.

These units need to be sufficiently charged to supply electricity if called upon during a period of grid stress. Consequently, some operators might want to charge their batteries before the situation worsens.

Individually, this does not appear to be a major problem.

The difficulty arises when thousands of systems make a similar decision at virtually the same time.

Instead of easing the strain on the grid, the batteries could temporarily increase electricity consumption by drawing power to replenish their own reserves.

It is a paradox: equipment installed to provide system flexibility could, under certain conditions, drive up demand right before a critical moment.

The British report does not claim that this behavior is currently causing blackouts, nor does it recommend halting the expansion of battery storage.

The warning is more specific: the models used by operators need to account for this additional demand and the collective behavior of these devices.

The challenge now is to get thousands of batteries to act as one... The issue becomes even more intriguing when considering who controls these batteries.

Some belong to large, grid-connected projects, but many others may be distributed across homes, businesses, and small facilities. Each unit may respond to different incentives and make decisions independently.

For grid operators, however, what matters is the combined effect.

One possible solution lies in so-called aggregators and virtual power plants. Instead of allowing thousands of batteries to operate in isolation, these systems can coordinate their charge and discharge cycles as if they were a single large storage unit.

Thus, when there is a surplus of electricity, they will be able to absorb energy. When demand rises, they can feed some of it back into the grid. And, crucially, they can prevent thousands of units from simultaneously making a decision that disrupts the system's balance.

The expansion in Europe is far from over. SolarPower Europe projects that new annual installations could exceed 50 GWh by 2026 and reach 138 GWh by 2030.

This means the challenge will not simply be installing enough batteries.

The real issue will be coordinating them.

The greater the number of connected systems, the more important it becomes to predict when they will charge, when they will discharge, and how their individual decisions will affect the grid as a whole.

Ultimately, Europe may discover that the future of storage depends not just on having millions of batteries available, but on getting them to act—at the right moment—like a single, massive power plant.

 

mundophone