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Glossary · Energy industry & energy transition

Data protection

Data protection power system smart meter metering Digitalisation regulation

Data protection refers to the protection of natural persons against data about them being unlawfully collected, processed, linked, evaluated or disclosed. The General Data Protection Regulation (GDPR) determines when data are personal: when they relate to an identified or identifiable natural person. A person is also identifiable indirectly, for example via an identification number, location data or an online identifier. In the electricity system, this therefore concerns not only names, addresses and contract data. Meter readings, consumption time series, control information, device identifiers and billing data can also be personal data as soon as they can be attributed to a household or a person via the metering point, meter number or customer number.

Data protection is becoming more important in the electricity system because electricity is less and less often read only once a year and billed as a flat amount. Smart metering systems, digital grid management, variable tariffs, charging infrastructure, heat pumps, storage units and controllable consumption devices generate more data, often at short intervals. Annual consumption reveals little about life in a household. A load profile at quarter-hourly or even finer resolution, by contrast, can provide indications of presence, working hours, the use of appliances, the charging of an electric car or the operation of a heat pump. Data protection in the electricity system therefore does not protect abstract data sets. It limits concrete insights into way of life, business operations and economic activity.

Distinction from data security, cybersecurity and secrecy protection

Data protection is often equated with data security. The two are related but answer different questions. Data security asks whether data are protected against loss, manipulation, unauthorised access or technical disruption. Encryption, access controls, logging, a secure system architecture and organisational measures serve this purpose. Data protection, by contrast, asks whether data may be collected at all, for what purpose, who receives them, how long they are stored and what rights the persons concerned have.

A measured value can be transmitted very securely from a technical point of view and still be problematic under data protection law if it is used for an impermissible purpose. Conversely, processing may be legally permitted and nevertheless create a considerable risk because of poor safeguards. Cybersecurity widens the view to targeted attacks on digital systems, for example on smart meter gateways, control boxes, grid control technology or platforms for marketing flexibility. The three areas must be considered together but do not replace one another. EU internal electricity market law also separates them: for smart metering systems it requires, on the one hand, cybersecurity in line with the state of the art and, on the other, protection of privacy under EU data protection law.

Confidentiality is likewise not the same as data protection. Trade secrets of energy suppliers, grid operators or aggregators can be protected without any personal data being involved. The GDPR protects only natural persons. The data of an industrial company that is organised as a legal person therefore do not, in principle, fall under the GDPR. Trade secret protection and confidentiality obligations under energy law may apply to such data. In the case of sole proprietors, medical practices or family-run farms, the boundary is often blurred in practice: an electricity profile there can reflect both the economic activity and the private life of an identifiable person.

Why measurement data can be particularly sensitive

At first glance, electricity data appear technical: energy quantities in kilowatt hours, metering points, timestamps, meter numbers. They become sensitive through three things together: temporal resolution, attributability and the possibilities for analysis. A monthly value usually says less than a quarter-hour value. An aggregated time series for an entire grid area is less personal than the profile of a single household. A single meter reading reveals less than a long time series that is linked with weather data, tariff information, device data or mobility data. The Metering Point Operation Act defines measured values as quantities of energy that a connection user has withdrawn, generated or fed in during a given period. In load profile metering (Zählerstandsgangmessung), meter readings for electricity are recorded every quarter of an hour.

A household's annual electricity consumption primarily describes a quantity that is billed. The profile over days and weeks, by contrast, describes behaviour. If controllable installations such as wallboxes, heat pumps or battery storage are also integrated, further data points are added: enablements, blocking times, charge states, switching operations and power limitations. These data may be necessary for grid operation and billing. But they can also allow conclusions that are not needed for the original purpose. Grid state data such as voltage and current values or phase angles primarily describe the grid. If they are collected at an individual house connection, however, they too can be personal data.

Data minimisation is therefore central. Under Art. 5 GDPR, data must be adequate, relevant and limited to what is necessary for the purpose. Purpose limitation and storage limitation are added to this. Data minimisation does not require using as little data as possible in the electricity system. It requires that scope, accuracy, retention period and circle of recipients fit the respective purpose. An annual bill requires different data than a dynamic electricity tariff. Keeping a low-voltage grid stable requires different information than marketing flexibility. The fact that finer data can be captured technically makes it neither factually nor legally necessary to pass them on to as many bodies as possible.

Legal framework in the EU and Germany

In the EU, the GDPR applies as the general framework. The Internal Electricity Market Directive (EU) 2019/944 additionally requires Member States to organise the management of metering data so that access and exchange are efficient and secure and data protection and data security are preserved. Personal data are processed in accordance with the GDPR. The Directive also provides that smart metering systems enable metering and settlement at the time resolution of the imbalance settlement period. Customers are to receive their validated historical consumption data on request at no additional cost.

In Germany, the Metering Point Operation Act (MsbG) supplements the GDPR for data from metering points. The Act was last amended on 18 December 2025. It is deliberately narrow in scope: personal data within its scope may be processed only by the authorised bodies exhaustively listed in § 49 para. 2. These include, among others, metering point operators, grid operators, balance coordinators and energy suppliers. In addition, there is any body that holds a valid consent of the connection user under Art. 7 GDPR. § 49 para. 1 expressly excludes processing on the basis of other federal or Land provisions.

The MsbG also specifies which measured values, grid state data and master data may be collected (§§ 55 to 59), which body receives which data for what purpose (§§ 60 to 70) and when data must be deleted or anonymised. Grid operators, transmission system operators, balance responsible parties and other recipients must delete or anonymise personal measured values as soon as they no longer need them for their task. Under § 52 para. 3, data must be anonymised or pseudonymised to the extent the purpose allows. Under § 49 para. 5, the supply of energy or access to tariffs must not depend on customers providing personal data that are not required.

The smart meter gateway is more than a metering device. The MsbG defines it as a communication unit that securely connects meters and installations to a communication network while ensuring data protection, data security and interoperability. The basis for this is protection profiles and technical guidelines of the Federal Office for Information Security (BSI). Data exchange between the market roles takes place via standardised market communication processes.

Roles, legal bases and purpose limitation

Data protection in the electricity system is not only a question of the consent of individual customers. Metering point operators record and transmit measured values. Grid operators need certain data for grid operation, balancing and forecasts. Suppliers need data for billing and tariffs. Direct marketers, aggregators or platform operators use data when they pool, control or deploy installations on the market. Each of these roles has its own purposes and its own responsibility. The MsbG itself points out that measured values are processed to perform contracts, to comply with legal obligations and to carry out tasks in the public interest.

A common misunderstanding sees data protection mainly as a consent hurdle. However, consent is only one possible legal basis. Many processes are based on the performance of a contract or on statutory obligations. An important restriction applies to data from metering points: here the MsbG exhaustively regulates the circle of authorised parties. Companies not listed in this catalogue therefore cannot simply rely on a general legitimate interest but need consent. This is precisely why purpose limitation is so important. If a measured value is collected to assess the grid state, it may by no means be used for advertising, credit checks or detailed behavioural analyses. Anyone who wants to understand the effect must look at the specific rule that permits a data flow.

Practical significance for the grid, the market and flexibility

A more strongly electrified energy system requires more coordination. Heat pumps, electric vehicles, battery storage and industrial loads can shift their electricity demand in time or respond to price signals. This requires data: current or forecast consumption, available capacity, grid bottlenecks, tariffs, control commands and feedback. Data protection does not replace this coordination. But it sets limits to it and requires suitable procedures.

For grid operation, aggregated or locally limited information may suffice as long as the billing of individual customers is not at issue. Variable tariffs require time-resolved measured values because the price is billed per time interval. In grid-supportive control, it must be clear which installation at which grid connection point may be influenced and which minimum requirements for comfort, operational safety and transparency apply. Different purposes therefore require different data qualities. If they are mixed, unnecessary risks and unclear responsibilities arise.

Data protection also plays an economic role. Data have value because they improve forecasts, reduce risks and enable new business models. A supplier can use load profiles to calculate its procurement more precisely. An aggregator can pool flexible installations. A grid operator can invest in a more targeted way if it knows the load in the low-voltage grid better. At the same time, data can create unequal power relations: anyone who knows consumption behaviour very precisely can design tariffs, offers or control options differently from a competitor without this information. Data protection does not prohibit such use across the board. But it requires verifiable purpose limitation and clear roles.

Typical misinterpretations

  • “Data protection prevents digitalisation.” Many delays have other causes: unclear responsibilities, slow rollout processes, complex market communication rules, technical certifications and inconsistent incentives. Data protection can raise requirements and make procedures more laborious. But it does not on its own explain why digital metering infrastructure is being introduced slowly.

  • “Anonymised data solve the problem.” True anonymisation means that a person can no longer be identified with realistic effort. With high-resolution electricity profiles this is difficult, above all if data sets can be linked with other information. Pseudonymisation replaces direct identifiers with codes. Pseudonymised data nevertheless remain personal data under the GDPR if they can be re-attributed with additional knowledge. For billing, balancing and control, the attribution to the metering point often remains necessary anyway.

  • “Transparency means unlimited data access.” For customers, transparency means that they can see in an understandable way which data are processed for what purpose. The MsbG gives them their own information rights for this. For grid operation, transparency means that bottlenecks are justified in a comprehensible way. It does not follow that every body needs the raw data of every connection. Good data architecture separates purposes, reduces resolution where possible and logs access where precise data are necessary.

Data protection is thus not a side issue of digitalisation. It determines under which conditions measured values, control data and consumption profiles may be used. In practice, it separates the necessary use of data for billing, grid operation, tariffs and flexibility from unnecessary or off-purpose analysis. The more closely electricity consumption, heat, mobility and digital control grow together, the more important this distinction becomes.

Sources

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Edited by eCMS on 11.11.2026 18:30

© 2026 Erik Schmidt. All rights reserved. Quotations with a link to the source are welcome.