Dynamic Line Rating at the Distribution Edge
The use of DLR by DSOs and the challenges of regulations and wide scalable deployment.
João Galamba
Paulo Monteiro
Felipe LooseText of the opening pages
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G R I D S I G H T ® W H I T E P A P E R · D Y N A M I C L I N E R A T I N G · E U R O P E Dynamic Line Rating at the Distribution Edge The use of DLR by DSOs and the challenges of regulations and wide scalable deployment. A U T H O R S €40–85 bn EU distribution investment DLR could defer by 2030 47% of Portuguese HV nodes already saturated ~2% of the cost of reconductoring the same lines Felipe Loose Head of Technical Sales & Solutions Architect @ Enline João Galamba Head of Regulatory Affairs @ Enline Paulo Monteiro Head of Business Delivery @ Enline
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W H I T E P A P E R · D Y N A M I C L I N E R A T I N G A T T H E D I S T R I B U T I O N E D G E 0 1 — C O N T E X T Introduction The distribution grid, the layer closest to consumers and producers, now absorbs most of the pressure for grid capacity. It hosts distributed and variable generation, increasing volumes of variable loads, and increasingly faces the same challenges as the transmission system: more variable and bi- directional flows, tighter margins and less real-time visibility. Once treated as a purely radial, one- directional network, the distribution grid has been redefined by the penetration of renewable generation, battery energy storage systems, large-scale charging stations, and other variable loads that now push power, bidirectionally, across widely ramified networks. At the same time, distribution system operators DSOs across Europe are entering tariff periods that, for the first time, tie remuneration to how efficiently existing network capacity is used rather than only to how much new capacity is built. Dynamic Ratings – Dynamic Line Rating DLR) and Dynamic Transformer Rating DTR –, the real-time calculation of ampacity from actual weather and loading conditions, instead of fixed, conservative assumptions, is the operational tool that makes this efficiency visible and actionable. Focussing on DLR, two questions still stand in the way of large-scale adoption: (i) which regulatory incentives actually make that deployment worthwhile? And (ii) how to cover thousands of kilometers of lines without inflating CAPEX? This article addresses both, the first through the reforms now under way, the second through how DLR is deployed using Enline's technology to surpass the high scale challenge. 0 2 — R E G U L A T I O N The regulatory shift: new opportunities ahead Distribution tariff frameworks across most of Europe were built to remunerate capital deployment, and not the operational use of capacity that already exists. For example, a DSO investing in reinforcement earns an allowed return through its regulatory asset base RAB. In other words, using the existing line more intelligently has, historically, earned it nothing. Fortunately, recent European reforms are beginning to correct that bias. Both the EU Electricity Market Design reform of 2024 and the forthcoming Grids Package are strengthening the economic case for non-firm and flexible capacity connections and for treating the existing grid as a resource to be optimized rather than merely expanded. The Market Design reform creates the legal entitlement, helping connect more renewables1 and storage in congested areas and those awaiting reinforcement through non-firm, flexible connection agreements, while entitling grid users with a Power Control System to a flexible connection offer and mandating quarterly publication of granular grid capacity data. The Grids Package, building on the 2023 EU Action Plan for Grids, extends this logic further, pushing operators to optimize the existing network rather than default to costly expansion. Together with parallel national reforms, these instruments are reshaping the incentives around how grid capacity is EU electricity market design reform of 2024 Regulation EU 2024/1747 (amending Regulations EU 2019/943 and EU 2019/942) and Directive1 EU 2024/1711 (amending Directive EU 2019/944, which reinforce system flexibility, non-fossil flexibility support and grid-connection rules. See also Cuatrecasas, "Key points: reform of European electricity market design under Regulation EU 2024/1747" 2024. For the Grids Package see European Commission, Communication on the European Grids Package, COM2025 1005 final, 10 December 2025 enline.energy 2
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W H I T E P A P E R · D Y N A M I C L I N E R A T I N G A T T H E D I S T R I B U T I O N E D G E allocated and used. The Netherlands, home to Europe's most congested grid , is the clearest2 example. The regulator ACM) and DSOs, such as Liander and Enexis, now offer capacity-limitation contracts and non-firm connection agreements, letting industrial consumers and solar developers accept variable capacity in exchange for faster grid access and lower tariffs, and letting operators safely "oversell" firm capacity. Therefore, this is the environment in which DLR moves from a nice-3 to-have to a core operational lever. Portugal is following the same path. Its distribution operator, EREDES, has taken the first steps toward a flexibility market and now publishes a quarterly reception-capacity map, signaling to the market where capacity is scarce. Additionally, ERSE provides financial incentives for both ERedes and REN to provide flexible, non-firm grid access to the grid, thus promoting a financial incentive for increased asset utilization. The National Energy and Climate Plan is pushing for quick growth in renewable energy, even though we are facing longer wait times for connections. Hence, it was the regulator's encouragement to trial innovative solutions that prompted EREDES's own DLR evaluation.4 Moreover, EU distribution operators must raise grid investment by 5070% this decade, over €375 425 billion by 2030, with roughly 455 GVA (giga volt-amperes, taken in apparent power values) of battery-storage projects alone stuck in distribution connection queues. In this context, deploying DLR could defer 1020% of that bill, on the order of €4085 billion, by unlocking capacity already in the ground Figure 1. F I G U R E 1 The distribution investment bill and the slice DLR defers: a conservative 1020% uplift postpones €4085 bn of the €375425 bn distribution gap to 2030. Sources: Eurelectric; IRENA and Energy Transitions Commission DLR deferral). Illustrative. Additionally, every euro of network reinforcement enters the regulated asset base and is recovered, with a return, through the tariffs that households and businesses pay. So the conventional answer to congestion, to build more infrastructure, quietly raises the bill for the very consumers the energy On the Netherlands facing Europe's most acute grid congestion, see IEA, "Grid congestion is posing challenges for energy security and2 transitions" 2024; and Regulatory Assistance Project RAP, "Gridlock in the Netherlands" 2024. ACM Netherlands Authority for Consumers and Markets), "ACM and system operators make binding arrangements on offering flexible3 contracts, the use of congestion management, and increased insight into grid utilisation" 2024. On Portugal: EREDES, "First steps in the flexibility market in Portugal" 2022, and its quarterly Reception Capacity map; Portugal's National4 Energy and Climate Plan PNEC 2030; national regulator ERSE; and reporting on Portuguese grid-connection constraints 2024. enline.energy 3
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W H I T E P A P E R · D Y N A M I C L I N E R A T I N G A T T H E D I S T R I B U T I O N E D G E transition is meant to serve. Thus, the investment on grid flexibility is of urgency, because only operating the grid more optimally will break the negative link and alleviate energy tariffs. Nevertheless, the use of DLR, in order to be efficient, must come with a massive large-scale deployment. Only when flexibility is applied across the whole distribution grid, rather than line by line, do the individual capacity gains aggregate into system-level savings large enough to bend the tariff curve that the consumer ultimately pays Figure 2. Therefore, Figure 2 shows an exercise of deferred CAPEX through the use of DLR over distribution systems. It rolls the distribution Regulated Asset Base RAB) forward to 2035, indexing the network- cost component of the bill to 100 in 2025: the index tracks allowed capital revenue, regulatory weighted average cost of capital WACC 5%) on the RAB plus depreciation 40-year asset life). At Eurelectric's €37 bn/yr, the build-led path lifts it about 14%; deferring 1020% of that investment Figure 1) holds the DLR path to about 8%, a roughly 40% smaller rise, and the gap is the pass- through avoided. F I G U R E 2 Illustrative network cost per consumer: a build-led path lifts tariffs faster than a DLR-enabled path, because deferred network CAPEX is deferred cost pass-through. Sources: Eurelectric; ACER/CEER tariff structure. 0 3 — S C A L A B I L I T Y Covering thousands of kilometers without inflating CAPEX A distribution operator manages tens of thousands of kilometers of overhead feeders. Any DLR strategy that depends solely on installing physical sensors may quickly become a capital and maintenance programme in its own right, increasing the very CAPEX problem DLR was meant to relieve, through recurring operations, maintenance, communications, and field-access costs. Furthermore, a DLR strategy that relies exclusively on physical sensors does not end the cost story, because a sensor only senses, it measures the immediate, present reality but does not forecast. To be useful in day-ahead, intraday, and real-time operations, sensor-based DLR requires additional forecasting tools, since power system operation is overwhelmingly predictive. enline.energy 4