Digitalising the Energy Transition
The model: from the meter to the billing system
Interactive model of the digital metering chain: how a meter reading and a control command travel through meter, gateway, administrator and market roles.
A quarter-hour reading travels a long way before it shows up on an electricity bill. It passes a device in the basement, a radio or wired network, at least two companies and a message in EDIFACT format. A control command under §14a covers almost the same distance. Just in the other direction, and over a different channel.
What tells the grid operator that it has to step in? Grid status data. The gateway delivers it under TAF 10, the metering point operator passes it on, and measurements in the local substation come on top. That is the third path, and it ends where the control command begins.
The model shows all three paths, step by step. Clicking a node shows what happens there, which chapter covers it and which deadline comes next. "Business" shows roles and tasks, "Technical" the interfaces behind them.
End-to-end model of the digital metering chain
The model as text
The same content as the graphic, node by node. This version works without JavaScript and in print.
The three paths
A meter reading on its way to the bill
- Meter: The meter measures and passes the reading to the gateway over the local metrological network.
- Smart meter gateway: The gateway turns them into values according to the tariff use case that is switched on, for billing usually quarter-hour values under TAF 7, then signs and encrypts them.
- WAN: The values leave through the WAN. Only recipients configured as authorised in the gateway can receive them.
- Metering point operator: The metering point operator checks the values, fills gaps with substitute values and prepares distribution.
- Market communication: As MSCONS messages, the values travel through market communication to the grid operator and the supplier.
- Supplier: The supplier bills. Under a dynamic tariff, this is where every quarter hour meets its price.
Grid status data for the grid operator
- Smart meter gateway: Under TAF 10 the gateway delivers grid status data from the grid connection: voltage, current, active power, phase angle and frequency.
- WAN: The values leave the house through the WAN, encrypted like any other reading.
- Metering point operator: The metering point operator passes them to the grid operator. Quarter-hour values, sent once a day, are a standard service under section 34 MsbG. Minute values cost extra and cover a quarter of the equipped connections at most.
- Grid operator: With measurements in the local substation and its grid model, the grid operator works out the grid status. Control needs real-time values: quarter-hour values that arrive once a day come too late. If the grid status shows an acute risk, the control command begins.
A control command under §14a
- Grid operator: The grid operator detects an acute risk to its grid from real-time measurements. Preventive control is only allowed as a transition, until the end of 2028 at the latest.
- Market communication: Through the API web service of market communication it instructs the metering point operator, without undue delay, which is presumed to mean five minutes at most after the grid status assessment.
- aEMT: The metering point operator sends the command over the control channel as the active external market participant, itself or through a service provider.
- WAN: The command reaches the gateway over the WAN, secured and authenticated.
- Smart meter gateway: The gateway passes it into the home network through the CLS channel, which the gateway administrator has set up.
- Control box: The control box executes the command, via relay or a digital interface such as EEBUS.
- Device or EMS: The device or energy management system reduces consumption, but not below the guaranteed minimum power.
Four roles, often one company
Behind four boxes there is often one company, the local grid operator. It is the default metering point operator unless it has handed that task over. It runs gateway administration itself or through a service provider, and as the active external market participant it sends the control commands.
Meter
Business view
Measures the energy. On its own it is a modern metering device: digital, with a display, no outside connection. Only together with the gateway does it become an intelligent metering system.
Technical view
Passes its readings to the gateway over the local metrological network (LMN), wirelessly via wireless M-Bus or by cable. The meter itself knows nothing about tariff use cases. Those run in the gateway.
In the book
- Chapter 2: Devices and architecture: what an intelligent metering system is
- Chapter 8: Rollout practice: figures, supervision and what nobody measures
Next deadlines
Smart meter gateway
Business view
The node where everything is decided. Based on the tariff use cases that are switched on, the gateway determines which readings go to whom and at what interval. It also opens the channel through which control commands reach the house.
Technical view
Three networks: LMN to the meter, HAN into the house (for the customer, service technicians and controllable devices via CLS), WAN to the outside. A security module holds the keys. Certified against protection profile BSI-CC-PP-0073 and technical guideline TR-03109-1.
In the book
- Chapter 2: Devices and architecture: what an intelligent metering system is
- Chapter 3: BSI standards, certification and the smart metering PKI
- Chapter 4: Tariff use cases: TAF 1 to 16 and version 2.0
- Chapter 5: Grid-oriented control under §14a EnWG
Next deadlines
Control box
Business view
Receives the control command from the gateway and passes it to the device. Whether the box is needed in the long run is open. Version 2.0 of the protection profile already describes a gateway that controls devices itself. Manufacturers report certifications for gateways with an integrated control module, but as of mid-October 2026 the BSI product list shows no certificate against that version (chapters 4 and 5).
Technical view
Sits in the home network on the gateway's CLS channel. Switches via relay contacts or talks to the device digitally, for example over EEBUS.
In the book
- Chapter 2: Devices and architecture: what an intelligent metering system is
- Chapter 5: Grid-oriented control under §14a EnWG
Next deadlines
Device or EMS
Business view
Heat pump, wallbox, air conditioner or storage. As a controllable consumption device under §14a it may be dimmed, and its operator pays a reduced grid charge in return (chapter 5).
Technical view
Controlled directly or through an energy management system that groups several devices in the house. Even when dimmed, a minimum power is guaranteed.
In the book
Next deadlines
WAN
Business view
Connects the gateway with the gateway administrator and the authorised market participants. Which medium works depends on where the device is installed, and in a basement that isn't always mobile radio.
Technical view
Every connection is TLS-secured and authenticated with certificates from the smart metering PKI. The metering point operator chooses the medium: mobile radio, 450 MHz radio, powerline or fixed line.
In the book
Next deadlines
Gateway admin
Business view
The gateway administrator sets up the gateways, installs profiles and firmware and switches tariff use cases on. The role belongs to the metering point operator, which either takes it on itself or hands it to a service provider.
Technical view
Administers over the WAN and also sets up the CLS channel for control commands. It needs two proofs: an ISMS certificate under ISO/IEC 27001 or IT-Grundschutz and an audit against TR-03109-6 (chapter 3).
In the book
- Chapter 3: BSI standards, certification and the smart metering PKI
- Chapter 5: Grid-oriented control under §14a EnWG
Next deadlines
aEMT
Business view
The active external market participant talks to devices in the house through the gateway. Under §14a this is usually the metering point operator or its service provider, because that is where the grid operator triggers control, through an API web service of market communication (chapters 5 and 7).
Technical view
Talks to the control box through the gateway's TLS proxy and needs a certificate from the smart metering PKI to do so. The gateway sets up the channel itself, triggered for example via the gateway administrator, because it can't be reached from outside.
In the book
Next deadlines
Smart metering PKI
Business view
Makes sure every gateway and every market participant knows who it is talking to. Without a valid certificate, no connection is established.
Technical view
A certification service provider runs the root instance under BSI supervision. Below it, sub-CAs issue certificates for gateways, gateway administrators and external market participants, as described in TR-03109-4.
In the book
Next deadlines
Metering point operator
Business view
Responsible for installation, operation and measurement. By default this is the local grid operator, unless it has transferred the task, and only the default operator has to meet the rollout quotas. Customers can commission a competitive metering point operator.
Technical view
Receives the readings from the gateway, validates them, fills gaps with substitute values and distributes them to grid operator and supplier through market communication. Grid status data under TAF 10 goes to the grid operator, quarter-hourly as a standard service under section 34 MsbG.
In the book
- Chapter 1: The legal framework: from the GDEW to today's MsbG
- Chapter 4: Tariff use cases: TAF 1 to 16 and version 2.0
- Chapter 6: Dynamic tariffs and grid charges in transition
- Chapter 7: Market communication: how meter readings become processes
- Chapter 8: Rollout practice: figures, supervision and what nobody measures
Next deadlines
Market communication
Business view
The prescribed processes through which readings, master data and switches flow between market roles: supplier switching, balancing, billing (chapter 7). The grid operator's control order to the metering point operator passes through here as well.
Technical view
EDIFACT messages such as MSCONS for readings, UTILMD for master data and UTILTS, which stays in place under BK6 notice no. 58, transmitted over AS4. Plus API web services, so far only for MaLo identification and control commands.
In the book
Next deadlines
Grid operator
Business view
Needs readings for balancing and grid charges, and grid status data to see its low-voltage grid at all. Under §14a it controls curatively, when real-time measurements show an acute risk; preventive control is only allowed as a transition until the end of 2028 (chapter 5).
Technical view
The metering point operator sends it grid status data under TAF 10, quarter-hourly as a standard service, minute by minute only as an additional service for at most a quarter of the equipped connections (chapter 4). Measurements in the local substation come on top (chapter 5). It triggers control commands at the metering point operator through an API web service; from there they run via the aEMT and the CLS channel.
In the book
- Chapter 4: Tariff use cases: TAF 1 to 16 and version 2.0
- Chapter 5: Grid-oriented control under §14a EnWG
- Chapter 6: Dynamic tariffs and grid charges in transition
- Chapter 7: Market communication: how meter readings become processes
Next deadlines
Supplier
Business view
Bills the customer. A dynamic tariff needs quarter-hour values from an intelligent metering system, usually the register profile under TAF 7 (chapter 6).
Technical view
Receives the readings from the metering point operator as MSCONS via market communication and bills them against the tariff, quarter hour by quarter hour for a dynamic tariff.
In the book
- Chapter 4: Tariff use cases: TAF 1 to 16 and version 2.0
- Chapter 6: Dynamic tariffs and grid charges in transition
- Chapter 7: Market communication: how meter readings become processes
Next deadlines
BSI
Business view
The Federal Office for Information Security specifies how gateway, administration and PKI must be secured, and certifies the devices.
Technical view
Technical guideline TR-03109 with its parts, protection profile BSI-CC-PP-0073, supervision of the root instance of the smart metering PKI (chapter 3).
In the book
Next deadlines
Federal Network Agency
Business view
Sets the market processes and the rules for §14a (chapters 5 and 7) and supervises the rollout (chapters 1 and 8).
Technical view
Determinations of ruling chamber 6, including GPKE, WiM, MaBiS and BK6-22-300 on control under §14a, plus BK8-22/010-A of ruling chamber 8 on grid charges under §14a, and supervisory proceedings under §76 MsbG.
In the book
- Chapter 1: The legal framework: from the GDEW to today's MsbG
- Chapter 8: Rollout practice: figures, supervision and what nobody measures
Next deadlines
What the model shows and what it leaves out
It is a simplification, and a deliberate one. One meter, one gateway, one device. In the field a gateway often serves several meters, and the control channel can reach more than one device. Chapter 2 explains how that fits together.
The roles are pulled apart too, even though in practice they often sit in one company. The local grid operator is also the default metering point operator unless it has handed that task over, and gateway administration is in turn handled by the metering point operator, either itself or through a service provider. As the active external market participant it also sends the control commands. Four boxes in the model can be a single company. The button "Four roles, often one company" highlights them.
What's missing? The transmission system operator, balancing groups, the planned MaBiS hub, redispatch, and anything to do with gas, water or heat. Those topics are in the reading paths. Here they would have made the picture unreadable. The local substation has no box of its own either, although chapter 5 advises measuring there first for the grid status. It appears in the text on the grid operator.
And the order of the steps is for explanation, not a process standard. Anyone who wants to fix a procedure in a contract should read the Federal Network Agency's determination, not this graphic.
How the model stays current
Nothing in this graphic is copied. The deadlines at each node come from the deadline calendar, which is rebuilt every night. Which chapters belong to a node is recorded in the book's chapter register. When a deadline changes in the calendar, it changes here the next morning.
The node texts, on the other hand, are handwritten. They are checked together with the chapters, most recently on the date shown above.