Submetering

Submetering refers to the use of dedicated measuring devices (DMDs) installed behind the customer’s main grid connection point to measure individual circuits, loads, or appliances — such as an EV charger, heat pump, battery inverter, or industrial process — rather than total building consumption. Submetering is the measurement layer that makes individual distributed energy resources (DERs) visible, verifiable, and independently dispatchable in flexibility markets.

The measurement problem submetering solves

A DSO‘s smart meter at the connection point (“uttagspunkt” in Swedish) measures aggregate consumption and production for the whole building. When multiple DERs — an EV charger, a heat pump, and a rooftop battery — share that connection point, the meter cannot distinguish their individual contributions. From the meter’s perspective, all three together look like one fluctuating load.

This creates three problems for Flexibility markets:

1. Attribution failure: when an aggregator dispatches the EV charger for a flexibility event, it is impossible to verify from the whole-building meter how much the charger specifically contributed, as opposed to unrelated household consumption changes at the same time.

2. Baseline inaccuracy: baseline calculations — the counterfactual “what would we have consumed without activation” — are noisier when they include other building loads. A whole-building baseline is contaminated by independent load shifts in other appliances during the activation window.

3. Sub-threshold invisibility: a 7 kW EV charger in a commercial building consuming 500 kW is entirely invisible at the connection point. Without a DMD, it cannot be individually registered, verified, or compensated in a flexibility market.

EU regulatory basis — Art. 7b EMD Reform

The Electricity Market Design Reform Regulation (EU 2024/1747, Art. 7b) introduces a customer right to install dedicated measuring devices. Key provisions:

• Customers (including aggregators acting on their behalf) may install DMDs for individual circuits, loads, or appliances within their premises
• The right applies independently of the DSO’s smart meter infrastructure — DMDs are an additional layer, not a replacement
• Art. 7b creates the EU legal basis; implementation rules (technical standards, data format, access rights, cost recovery) remain pending at member-state level as of 2026

This right is significant because it formally recognises that the connection-point smart meter is insufficient for the individual DER measurement that Aggregation and explicit Demand Response require at scale. It also establishes that customers and aggregators may install measurement devices without DSO consent — removing a potential gatekeeper role. See Electricity Market Design Reform 2024 for the broader package context.

Settlement-grade vs indicative submetering

A key conceptual distinction introduced in the Comillas/BeFlexible research (Source - Submetering for Flexibility Services Comillas (2024)):

Policy implication: most flexibility applications need indicative-grade only — not settlement-grade. Requiring settlement-grade for all submetering would impose disproportionate costs and slow adoption. Regulatory frameworks should explicitly distinguish the two tiers. The NC DR Art. 7b implementation guidance at member-state level is where this distinction should be codified.

Technical requirements for flexibility-grade submetering

Based on BeFlexible project findings:

Submetering and baseline accuracy

The connection between submetering and Baseline Methods is direct: a DMD measuring a specific DER in isolation provides a clean, device-specific baseline that is not contaminated by other building loads.

Without submetering (whole-building baseline):

• Baseline includes all building loads — fluctuations in appliances, occupancy, weather response, and DER operation all appear as one combined signal
• Activation verification is approximate; disputes about actual delivery are common
• Particularly problematic for batteries (which cycle independently of building loads) and EV chargers (which have highly variable charging sessions)

With submetering (device-level baseline):

• Only the specific DER’s consumption/production is measured
• Activation delivery is unambiguous — the DMD records pre/post deviation for that device alone
• Battery gaming risk (MBMA manipulation via pre-activation charging/discharging) is isolated and can be detected

For multi-DER aggregated portfolios, submetering enables the per-DER attribution needed when different DER types should use different baseline methods (batteries → zero baseline; consumption loads → MBMA or rolling average).

Submetering and independent aggregation

Submetering is enabling infrastructure for independent aggregators. Without DMDs, an aggregator dispatching a DER in a multi-DER building cannot verify delivery independently — it depends entirely on the DSO’s whole-building meter data, creating potential data access friction.

With DMDs:

• The aggregator installs its own measurement at the DER level
• Verification is independent of the DSO’s AMI infrastructure
• The aggregator can confirm dispatch without waiting for DSO meter data
• Data ownership is clearer: the DMD data belongs to the customer (or aggregator with customer consent)

This also connects to the NC DR single-CU site registration concept: a DSO registers the whole site as one Controllable Unit at the connection-point meter; the aggregator then uses device-level DMD data to manage and verify individual DER dispatch within that site.

Swedish context

Swedish DSO pilots (for congestion management) represent some of the earliest European operational uses of submetering in flexibility applications. Key characteristics of the Swedish situation:

• DSO-initiated pilots: submetering has been deployed by DSOs to observe DER behaviour, rather than customer-initiated for flexibility participation — raising data ownership and access questions
• AMI reform context: Sweden’s next-generation AMI (smart metering reform) is the infrastructure context within which submetering must fit; DMDs should complement the AMI rollout, not duplicate it
• Art. 7b implementation: as of 2026, Ei has not yet issued specific guidance on Art. 7b DMD rights in Sweden; the DHV/FIS architecture proposal (due September 2026) may address how DMD data interacts with the central data infrastructure

The meter’s open interface vs the DMD right — these are distinct. The DSO smart meter has its own öppet kundgränssnitt (a standardised HAN-port-type interface giving near-real-time access to the connection-point mätvärden, required by förordning 1999:716 and the mätföreskrifterna EIFS 2025:1) — this is the meter reading itself, not a behind-the-meter device-level DMD. From 1 January 2027, Ei‘s EIFS 2026:8 (4 kap. 4 §) requires every DSO to publish, on its website/app, information about this interface and which dataprotokoll it supports, and to show on mina sidor whether the interface is active. The duty follows Ei’s spring-2025 riktad tillsyn, which found that missing dataprotokoll information was limiting consumer choice and undermining the open-interface requirement: third-party makers of realtidsmätare and steering services cannot build compatible products without knowing the supported protocol. Publishing the protocols rather than naming brands preserves DSO neutrality. EIFS 2026:8 does not address the Art. 7b device-level DMD right — so the öppet kundgränssnitt (meter, near-real-time read) and the Art. 7b DMD (behind-the-meter, settlement/indicative submetering) remain two separate layers; the gap below stands. (Source - EIFS 2026-8 Nätföretags Information till Elanvändare (2026))

The Network Code on Demand Response T&C development in Sweden (12-month window after NC DR entry into force) is where the practical rules for DMD use, data access, and baseline methodology will be established. The settlement-grade vs indicative distinction is directly relevant to how Ei and Svk define measurement requirements for NC DR service providers.

BeFlexible practitioner survey

Current use of submetering for flexibility services is limited — most DSO pilots rely on whole-building meters or proxy measurements. The three main barriers identified:

1. Cost: hardware purchase, installation, and ongoing maintenance; no standard EU/national cost-recovery mechanism
2. Regulatory uncertainty: data ownership unclear — who controls DMD data when it is installed in customer premises by an aggregator?
3. Data management complexity: each additional DMD adds a data stream that must be reconciled with building-level and market-level data

Practitioners see submetering as a short-term enabler bridging the period until next-generation smart meters with sub-circuit reading capability are deployed at scale. (Source - Submetering for Flexibility Services Comillas (2024))

Relationship to other concepts

• Aggregation — DMDs enable DER-level attribution for aggregated portfolios
• Baseline Methods — device-level baselines from DMDs improve accuracy and reduce gaming risk
• Demand Response — explicit DR requires verifiable delivery; submetering provides the measurement infrastructure
• Flexibility Communication Protocols — DMD data must be communicated to aggregator platforms and DSO systems in standard formats (CIM, DLMS/COSEM)
• Electricity Market Design Reform 2024 — Art. 7b is the EU legal basis
• Network Code on Demand Response — baseline and settlement framework will shape how DMDs are used in EU markets

Data gaps

• Swedish regulatory status of Art. 7b DMD right — has Ei issued guidance or included DMDs in the AMI reform process?
• Cost benchmarks for DMD hardware and installation in Swedish residential context
• Which Swedish DSO flexibility pilots use submetering, and for what specific application?
• How does the DHV/FIS architecture (report due September 2026) plan to handle DMD data flows?