The Energy Agency of the Republic of Serbia, AERS, is consulting until Sept. 30 on new rules covering supplier switching, collective supplier switching and aggregator switching for electricity customers with full-supply contracts. The consultation focuses on how customers can change the company responsible for monetising their flexible consumption or distributed energy assets. Regulators say the move supports a more competitive market for electricity aggregation.
Serbia’s electricity Market Code already includes aggregators in the market framework. In practice, an aggregator’s role is distinct from electricity supply: it combines flexible demand, generation or other controllable resources from multiple customers and offers the resulting portfolio into electricity markets. EMS allows an aggregator to submit a single balancing bid for its aggregation group.
Eligible balancing-service providers can include generators, aggregators, storage operators and final customers, subject to technical qualification. This structure underpins a market for electricity services that runs alongside supply arrangements. A factory could continue purchasing power from one supplier while another specialist manages flexible loads such as pumps, compressors, heating and cooling equipment.
Aggregator switching and competition over customer flexibility
Under the proposed approach, creating a defined mechanism for changing an aggregator begins to separate aggregation from the traditional supplier relationship. For industrial consumers, this could eventually affect competition over who manages their flexibility. If multiple aggregators pursue the same portfolios, customers may compare revenue-sharing arrangements, optimisation services and contractual terms.
The model also relies on aggregators building portfolios rather than owning generation assets. An aggregator can contract with electricity consumers to control agreed parts of their demand, then combine hundreds of smaller resources into a single market-facing portfolio. For Serbian industry, unused operational flexibility could become an additional revenue stream.
Energy companies could use aggregation as a customer-acquisition channel, including by adding aggregation to existing electricity contracts. Independent firms could specialise in demand response, industrial optimisation or virtual power plants, while technology providers can supply forecasting, telemetry and automated control systems. The commercial value depends on whether customers can exit aggregation arrangements when needed.
Switching rules are therefore central because flexibility contracts can otherwise become sticky. Industrial customers may be reluctant to grant operational access to equipment unless exit procedures, data responsibilities and switching arrangements are clearly defined. Standardised switching is intended to reduce some of that friction and support more competitive behaviour among aggregators.
ADEX integration targets common intraday trading limits
Power traders active across Serbia, Hungary and Slovenia are preparing for a new common intraday trading environment designed to improve management of trading limits and working capital across the three markets. Under the ADEX integration, continuous intraday markets run through SEEPEX, HUPX and BSP SouthPool are expected to move into a shared M7 trading environment with launch planned for October 2026. The visible change is a common trading interface.
The commercial change is linked to how limits are handled after integration. European Commodity Clearing, ECC, plans to replace existing market-specific trading limits with a single ADEX trading limit covering participating markets. A trading company active on several exchanges typically has to manage operational limits separately by market.
Under the new setup, participants still need admission to each market they want to trade, while physical settlement, financial settlement, margining, products and reporting remain market-specific. The reform does not create one fully pooled clearing system; instead it makes trading-limit management common across markets. A regional desk could manage available limit capacity across Serbia, Hungary and Slovenia through one ADEX framework rather than maintaining separate market-specific limits.
The development also highlights collateral and treasury management as part of trading capacity constraints. Trading opportunities require sufficient limits and collateral to execute positions, and collateral requirements can become a major constraint during volatile periods. ECC has told participants to coordinate with their clearing banks before migration because existing limits will not transfer automatically.
Romania introduces financial guarantees for scarce grid capacity allocation
Romania is increasing the financial cost of holding speculative projects by turning access to scarce grid capacity into a more capital-intensive element of energy development. Transmission operator Transelectrica has launched infrastructure for allocating available grid capacity through competitive procedures. Regulator ANRE has also increased financial guarantees required from developers.
For the 2026 allocation process, applicants must provide a guarantee of €20,000 per MW of requested capacity. A 100-MW project would therefore need a €2 million participation guarantee simply to enter the allocation process. Transelectrica’s platform accepts capacity applications, validates financial guarantees and prepares eligible projects for auction.
The first 2026 application round ran from July 1 to July 14. The stated objective is to allocate scarce network capacity to projects with sufficient financial commitment rather than allowing large volumes of speculative applications to occupy the connection queue. ANRE has also tightened other parts of the connection regime.
For qualifying projects, the financial guarantee tied to securing a connection approval increased from 5% to 20% of the connection tariff excluding VAT. Developers seeking establishment authorisations face an additional guarantee of €30/kW of installed capacity subject to applicable regulatory conditions. Developers may therefore need bank guarantees, credit lines or equity commitments earlier in the development cycle.
Croatia shortens balancing reserve products into four-hour blocks
Croatia has shortened the time commitment required to sell balancing capacity as part of changes introduced by transmission operator HOPS. HOPS launched a new balancing platform on Sept. 15, along with revised procurement rules for aFRR and mFRR balancing capacity and energy. The key procurement change moves away from offering reserve capacity for an entire day.
Instead of day-long products, providers can bid into six four-hour blocks through day-ahead procurement. The product structure is intended to be more compatible with flexible electricity demand patterns that vary within shorter windows than 24 hours. An industrial site may be able to guarantee flexibility from midday to 1600 hours, while other resources may only be available at specific times.
The resource still needs to satisfy HOPS qualification and contractual requirements before it can target periods when flexibility is available. HOPS also changed balancing-energy bidding so bids can be submitted for individual Market Time Units and modified until 25 minutes before the relevant MTU begins . Providers can communicate via a graphical interface or machine-to-machine connectivity.
Croatia prepares for PICASSO and MARI balancing integration in 2027
The new platform supports Croatia’s preparation for connection to European balancing systems. HOPS expects connections to PICASSO for aFRR and MARI for mFRR during 2027. While integration steps are planned for next year, the immediate market impact remains domestic due to changes in how balancing capacity can be procured in shorter time slices .
The shift creates potential opportunities for aggregators, industrial consumers and EV fleets where flexibility availability aligns with four-hour blocks. It also increases reliance on automated processes as gate closure moves closer to real time and products become more granular . Aggregators and balancing-service providers need software capable of forecasting asset availability continuously and updating market positions automatically.
EU data-centre policy links grid connections with flexibility participation
The European Commission proposed on Sept. 21 a common EU rating system for data centres and opened consultation on possible minimum performance standards, with legislation planned for 2027. The policy emerges as Europe seeks both expanded computing infrastructure and management of its effect on electricity networks . The EU aims roughly triple data-centre capacity by 2035.
The Commission’s policy framing shifts the commercial question toward whether data centres should receive large firm grid connections or participate more actively in system flexibility . Data centres have traditionally been treated as highly reliable baseload consumers because computing services cannot simply shut down when constrained . However, some consumption components may be shiftable in time or geography through workload adjustments or thermal storage in cooling systems.
The policy also points to backup electricity infrastructure that can provide controllability under carefully managed conditions . It further notes that facilities can coordinate on-site generation, electricity procurement and other energy systems . In this context, future data-centre projects may need to demonstrate how much load is genuinely firm versus how much can respond to system conditions.
A new contracting approach around flexible megawatts instead of only megawatt-hours
The Commission argues that sustainable and flexible data centres able to adjust consumption based on grid conditions can lower system costs, improve grid stability and help integrate renewable electricity . For Southeast Europe’s digital investment plans across Romania, Greece, Bulgaria, Croatia and Slovenia, network capacity constraints can make flexibility commercially relevant when grid stress occurs . Projects able to reduce demand during rare stress periods may be easier and cheaper for the system than projects requiring maximum consumption under all conditions .
The trend also creates opportunities beyond data-centre operators themselves through third-party aggregation and optimisation services . Aggregators could manage flexible data-centre loads while energy-management companies could optimise power use across computing workloads, cooling systems and auxiliary equipment . Electricity suppliers could combine procurement with flexibility services while grid operators could potentially contract controllable demand rather than treating data centres entirely as passive load .
The Commission’s policy emphasises reuse of waste heat from data-centre cooling systems where suitable district-heating or industrial demand exists . It links this approach with power-to-heat developments under sector coupling trends . Site selection could therefore depend not only on fibre connectivity and electricity supply but also on whether nearby energy systems can use waste heat .
The Commission indicates that future contracting may extend beyond pricing megawatt-hours consumed toward pricing megawatts that data centres agree not to consume when needed most by the power system . Large customers may increasingly require an energy strategy covering how much electricity they need, when they need it, how quickly demand can change and what the grid pays for that flexibility . This framing reflects an expectation that contracts will incorporate both consumption profiles and controllability commitments .
