The Energy Agency of the Republic of Serbia, AERS, is consulting until Sept. 30 on new rules for supplier switching, collective supplier switching and aggregator switching for electricity customers with full-supply contracts. The consultation covers how customers can change the company responsible for monetising their flexible consumption or distributed energy assets. The agency’s proposal addresses switching procedures that could affect how flexibility is contracted and managed.
Aggregator switching rules for full-supply customers
Serbia’s electricity Market Code already recognises aggregators within the market framework. EMS allows an aggregator to submit a single balancing bid for its aggregation group, while eligible balancing-service providers can include generators, aggregators, storage operators and final customers, subject to technical qualification. The rules being consulted are intended to define a mechanism for changing aggregator arrangements.
An aggregator’s product is not electricity supply itself. It combines flexible demand, generation or other controllable resources from multiple customers and offers the resulting portfolio into electricity markets. Creating a defined mechanism for changing an aggregator therefore begins to separate aggregation from the traditional supplier relationship.
For industrial consumers, the ability to change aggregator could create competition over who manages their flexibility. A factory could continue buying power from one supplier while another specialist company manages flexible loads such as pumps, compressors, heating and cooling equipment capable of temporarily altering consumption. If multiple aggregators compete for customer portfolios, customers can compare revenue-sharing arrangements, optimisation services and contractual terms.
The portfolio-based model does not require owning generation to expand aggregation activity. An aggregator can build a portfolio by contracting with electricity consumers and controlling agreed parts of their demand, combining hundreds of smaller resources into a single market-facing asset. For Serbian industry, that could turn operational flexibility into an additional revenue stream, while energy companies could use aggregation as a customer-acquisition route.
Switching rules are commercially relevant because flexibility contracts can otherwise become sticky. Industrial consumers may be reluctant to grant third parties operational access to equipment unless contractual exit procedures, data responsibilities and switching arrangements are clearly defined. Standardised switching is intended to reduce friction and could also encourage more competitive behaviour among aggregators for customer portfolios.
Serbia remains at an early stage for demand response market liquidity despite the existence of rules. Customers still need controllable loads, adequate metering and communications infrastructure, while balancing resources must meet technical requirements. The next competitive dynamic in Serbia’s electricity market may therefore extend beyond pricing of megawatt-hours toward control of flexible megawatts and the revenue that can be extracted from them.
ADEX integration targets common intraday trading limits
Power traders active across Serbia, Hungary and Slovenia are preparing for a common intraday trading environment under the ADEX integration. Continuous intraday markets operated through SEEPEX, HUPX and BSP SouthPool are due to move into a common M7 trading environment, with launch planned for October 2026. The visible change is a common trading interface.
European Commodity Clearing (ECC) plans to replace existing market-specific trading limits with a single ADEX trading limit covering the participating markets. A trading company active on multiple exchanges typically manages operational limits market by market, which can fragment available trading capacity even when the same clearing structure supports positions across markets. Under the new setup, admission to each market remains required.
Physical settlement, financial settlement, margining, products and reporting remain market-specific under ADEX. The reform therefore does not create one fully pooled clearing system; instead it standardises trading-limit management across markets. A regional trading desk could manage available limit 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 electricity trading operations. Trading opportunities depend on sufficient limits and collateral to execute trades, with collateral requirements becoming a major constraint during volatile periods for smaller trading houses. Companies increasingly compete on how efficiently they use credit lines, guarantees and clearing-bank capacity as well as on price forecasting.
ECC has told participants to coordinate with their clearing banks before migration because existing limits will not transfer automatically. That creates work for treasury departments, clearing members and banks in addition to traders. ADEX’s shared M7 environment will also support harmonised connectivity and a new WebSocket API intended to reduce operational friction from maintaining separate trading infrastructure across neighbouring markets.
Romania introduces financial guarantees for scarce grid capacity
Romania is turning access to scarce electricity-grid capacity into an increasingly capital-intensive element of energy development as connection capacity becomes a balance-sheet issue. Transmission operator Transelectrica has launched infrastructure allocating available grid capacity through competitive procedures, while regulator ANRE has 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 processing. The first 2026 application round ran from July 1 to July 14.
The 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 by increasing the financial guarantee associated with securing a connection approval 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 need additional bank guarantees, credit lines or equity commitments earlier in the development cycle because weakly capitalised developers cannot reserve large volumes of connection capacity at minimal financial cost. This also affects renewable-energy M&A by expanding technical due diligence into grid-rights due diligence.
Croatia shortens balancing products into four-hour blocks
Croatia has shortened the time commitment required to sell balancing capacity as transmission operator HOPS launched a new balancing platform on Sept. 15. The platform was accompanied by revised procurement rules for aFRR and mFRR balancing capacity and energy. The most commercially important change concerns how reserve capacity is procured.
Instead of offering reserve capacity for an entire day, providers can bid into six four-hour blocks through day-ahead procurement. The product structure is designed to be more compatible with flexible electricity demand than long reserve products requiring availability across 24 hours. Once qualified under HOPS’ requirements, providers can target periods when flexibility is genuinely available.
Bids can be submitted for individual Market Time Units and modified until 25 minutes before the relevant MTU begins under HOPS’ revised balancing-energy bidding rules. Providers can communicate through either a graphical interface or machine-to-machine connectivity. As gate closure moves closer to real time and products become more granular, manual bidding becomes less efficient.
The platform is also part of Croatia’s preparation for connection to European balancing systems expected during 2027: HOPS expects to connect to PICASSO for aFRR and MARI for mFRR during that year.
The European Commission proposes data-centre performance standards
The European Commission on Sept. 21 proposed a common EU rating system for data centres and opened consultation on possible minimum performance standards, with legislation planned for 2027. The policy comes as Europe tries to expand computing infrastructure while managing its effect on electricity networks; the EU aims to roughly triple data-centre capacity by 2035. The commercial question raised in the proposal concerns whether data centres should remain large firm load users or become more active participants in power-system flexibility.
The Commission describes data centres traditionally treated as highly reliable baseload consumers because computing services cannot simply shut down when grids are constrained. It also notes that not all parts of data-centre consumption are necessarily equally inflexible: some computing workloads can potentially be shifted in time or geographically, cooling systems contain thermal flexibility, backup electricity infrastructure can provide additional controllability under carefully managed conditions, and facilities can coordinate on-site generation with electricity procurement and other energy systems.
The policy links grid connection design with data-centre operation by indicating that future projects may need to demonstrate how much load is genuinely firm versus how much can respond to system conditions. It also states that network capacity cannot always expand at the same speed as new demand in EU-member markets including Romania, Greece, Bulgaria, Croatia and Slovenia seeking renewable generation connections alongside electrification efforts.
The Commission also emphasises waste heat reuse in relation to data centres rejecting substantial quantities of heat through cooling systems where suitable district-heating or industrial demand exists nearby. It links this approach with power-to-heat and sector coupling trends by indicating that site selection could depend not only on fibre connectivity and electricity supply but also on whether nearby energy systems can use facility waste heat.
The policy indicates that large customers may need an energy strategy covering how much electricity they need, when they need it, how quickly demand can change and what the grid will pay for that flexibility. It states that sustainable and flexible data centres able to adjust consumption to grid conditions can lower system costs, improve grid stability and help integrate renewable electricity.
The Commission’s framing indicates that future data-centre electricity contracts may price both megawatt-hours consumed and megawatts agreed not to consume when the power system needs them most.