Southeast Europe’s next major power-market entrant may look very different from a traditional utility. It may own no turbine, dam, solar park or battery fleet. Instead, its core assets could be software, customer contracts, telemetry and access to flexible electricity consumption, allowing it to coordinate thousands of small production and consumption decisions.
This is the emerging model of the independent aggregator, and its commercial potential is growing as Southeast Europe confronts a problem that new generation alone cannot solve: a shortage of flexibility.
ACER’s 2026 assessment of Southeast Europe identifies limited flexible resources during the evening solar ramp as a structural contributor to regional price stress, alongside cross-border transmission constraints. The implication is increasingly clear. The power market is moving beyond the question of how many megawatts can be built toward how effectively existing megawatts can be controlled and shifted.
An aggregator brings together flexible loads and distributed energy assets into a portfolio large enough to participate in electricity markets. Individual resources may be relatively modest: industrial pumps, refrigerated warehouses, HVAC systems, EV chargers, behind-the-meter batteries, backup generators or prosumer installations.
Their value comes from coordination. A portfolio capable of reducing 20 MW of demand within minutes, increasing consumption during periods of oversupply or shifting electricity use from evening to midday can provide services traditionally associated with conventional balancing resources.
The critical advantage is that the aggregator does not necessarily need to finance the underlying assets. Instead, it monetises flexibility that is already embedded across the economy.
Where the market opens first
The opportunity is developing unevenly across the region. Greece already has dynamic retail pricing linked to smart-meter capabilities, making changes in customer consumption increasingly visible from a commercial perspective.
EU markets such as Romania, Bulgaria, Croatia, Slovenia and Hungary are also becoming more deeply integrated into European balancing platforms and active-customer frameworks.
Serbia and other Energy Community markets are still translating the rights of active customers into practical rules covering market participation, metering and settlement. This regulatory gap does not necessarily have to be a disadvantage. It gives regulators an opportunity to adopt market models already tested elsewhere, while giving regional suppliers and trading companies time to build customer portfolios before competition becomes more intense.
The first major addressable market is likely to be industrial and commercial rather than residential.
Supermarket chains can coordinate refrigeration systems across hundreds of stores. Water utilities can optimise pumping stations and reservoirs. Cement producers can shift selected auxiliary loads, logistics companies can manage EV charging and data centres can adjust cooling and backup systems within carefully defined limits.
Individually, these resources may be too small or operationally complex to participate directly in electricity markets. Aggregation converts that fragmentation into scale while also diversifying operational risk.
If one customer is unavailable, another may still be capable of responding. The portfolio can therefore provide a more reliable flexibility product than any individual customer.
The commercial model
The revenue opportunity extends well beyond balancing markets. A sophisticated flexibility portfolio can reduce supplier imbalance exposure, optimise customer capacity charges, capture value from dynamic electricity prices, participate in ancillary services and eventually provide local congestion-management services to distribution system operators.
This diversification is important because individual markets will not necessarily offer attractive returns for every asset at all times.
The most resilient aggregator will therefore operate more like an asset manager, continuously directing available flexibility toward the highest-value application while respecting the operational limits of each customer.
Contract design will be central. Customers need clearly defined boundaries covering maximum activation frequency, minimum notice periods, temperature or pressure limits, battery state-of-charge requirements and compensation for production interruptions.
The aggregator, meanwhile, needs reliable measurement and dispatch rights. Suppliers and balance-responsible parties need protection against uncoordinated deviations.
Revenue-sharing models can include fixed payments, performance-based compensation or flexibility provisions embedded within broader electricity-supply agreements. The strongest proposition may ultimately be one where the customer never interacts with the balancing market directly and simply receives a lower overall energy cost in exchange for making part of its consumption controllable.
What could stop the model?
The largest barriers are likely to be regulatory and operational.
Baseline methodologies must be credible. If they are poorly designed, markets risk paying for artificial reductions rather than genuine flexibility. Smart-meter data must also be available with customer consent, while prequalification requirements should verify real capabilities without imposing rules designed primarily for large conventional generators.
Clear balance-responsibility rules are equally important. Market participants must not be able to receive multiple payments for the same deviation, while cybersecurity will become increasingly critical as aggregator platforms gain the ability to control equipment across hundreds or thousands of sites.
Capital requirements represent another challenge.
An aggregator may own very few physical assets but can still face collateral requirements, technology costs and significant customer-acquisition expenses. A small software company may therefore struggle to compete with utilities and established trading houses that already have wholesale-market access, credit lines and 24/7 dispatch capabilities.
This makes partnerships increasingly attractive. Software companies, electricity suppliers and industrial-service providers could combine technology, customers, market access and balance-sheet strength to build portfolios at scale.
SEE outlook
The strategic implication is significant. Ownership of generation will no longer be the only route to influence in electricity markets.
A company controlling 500 MW of flexible demand could materially influence procurement and balancing positions without owning any of the equipment behind that capacity.
As European balancing integration develops through platforms such as MARI and PICASSO, flexible resources will increasingly be exposed to wider competition. This will place greater value on portfolio quality, availability, geographical distribution and response speed.
Southeast Europe’s flexibility market is therefore likely to develop in stages: industrial optimisation first, formal balancing-market participation next, followed by wider retail aggregation and local DSO services.
The company that builds the region’s first large cross-border portfolio of flexible customers could ultimately become a power-market platform in its own right.
The next phase of Southeast Europe’s energy transition may therefore produce a new kind of market leader—one that owns little physical infrastructure but controls a large amount of flexible capacity.
In that market, the most valuable megawatt may not be the one a company owns on paper, but the one it can reliably switch on or off when the power system needs it.
