1. Introduction

The General Data Protection Regulation (GDPR), Regulation (EU) 2016/679, has become increasingly important in electricity markets because modern electricity systems depend heavily on the collection, transmission and analysis of consumer data. Smart meters, advanced metering infrastructure, demand-response systems, electric-vehicle charging, distributed energy resources, dynamic tariffs and digital energy platforms can generate highly detailed information about electricity consumption.

Electricity-consumption data may reveal patterns about when people are at home, their daily routines and the operation of particular appliances. EU legislation therefore treats data protection as an important component of the smart-grid and electricity-market framework. The EU's smart-metering framework specifically recognises that electricity metering can involve personal data and requires compliance with data-protection law. (EUR-Lex)

The central legal question is:

How can electricity-market participants use detailed consumer data to operate competitive and efficient electricity markets without violating individuals' privacy and data-protection rights?

2. GDPR and the Electricity Sector

The GDPR applies whenever an electricity-sector entity processes personal data concerning an identifiable natural person.

Relevant actors can include:

electricity suppliers;

distribution system operators (DSOs);

transmission system operators (TSOs);

aggregators;

smart-meter operators;

energy-service companies;

demand-response providers;

energy-data platforms;

electric-vehicle charging operators; and

public authorities and regulators.

The electricity sector is particularly significant because smart meters can transform relatively limited billing information into high-frequency consumption data.

For example:

Traditional meter:

Monthly consumption = 450 kWh.

Smart meter:

Consumption recorded every 15 minutes.

The second dataset can potentially reveal much more about household behaviour. EU policy on smart metering has consequently emphasised data minimisation, anonymisation/pseudonymisation, security and impact assessments. (EUR-Lex)

3. Electricity Consumption Data as Personal Data

Article 4(1) GDPR defines personal data broadly as information relating to an identified or identifiable natural person.

In electricity markets, data can become personal data through:

customer names;

addresses;

customer numbers;

meter identifiers;

smart-meter readings;

account information;

consumption profiles;

billing records;

timestamps;

location information; and

combinations of otherwise apparently anonymous datasets.

Importantly, data do not necessarily have to contain a person's name to constitute personal data.

The Court of Justice has repeatedly adopted a broad interpretation of personal data. In SRB v EdPS (C-333/22 P), the Court emphasised that information may constitute personal data where it can be connected with an identifiable person, including through additional information. (EUR-Lex)

This principle is particularly relevant to electricity markets because a meter identifier can often be connected to a specific customer account.

4. Smart Meters and GDPR

Smart meters are perhaps the clearest example of GDPR application in electricity markets.

A smart meter can record:

electricity consumption;

time of consumption;

voltage information;

power flows;

meter status;

technical information;

customer identifiers; and

information necessary for remote management.

The EU's 2012 Smart Metering Recommendation already recognised that smart-metering systems could permit network operators and suppliers to move from broad information about energy behaviour to much more detailed information about individual consumers. It recommended data minimisation, anonymisation and appropriate retention periods. (EUR-Lex)

GDPR principles relevant to smart meters

The principal Article 5 GDPR principles include:

Lawfulness, fairness and transparency

Purpose limitation

Data minimisation

Accuracy

Storage limitation

Integrity and confidentiality

Accountability

Thus, an electricity company cannot simply collect every technically available piece of smart-meter information because it might become useful in the future.

5. Lawful Basis for Processing

Article 6 GDPR requires a lawful basis for processing personal data.

In electricity markets, possible legal bases can include:

A. Contractual necessity

An electricity supplier may need certain personal data to:

establish an electricity account;

calculate bills;

administer a supply contract; or

provide electricity services.

B. Legal obligation

An operator may process information because EU or national electricity legislation requires it.

For example, energy legislation may require meter readings for settlement, billing or regulatory purposes.

C. Legitimate interests

An undertaking may sometimes rely on legitimate interests, provided that the necessary balancing and other GDPR requirements are satisfied.

D. Consent

Consent may be appropriate for certain optional services, but it cannot simply be used as a substitute for identifying the correct legal basis where processing is actually required by law or contract.

This distinction is particularly important in electricity markets because some data processing is essential for system operation, whereas other processing—such as certain commercial profiling—may be optional.

6. Purpose Limitation

Purpose limitation is especially important in digital electricity markets.

Suppose a supplier collects smart-meter data for:

electricity billing.

It cannot automatically assume that the same information may be used for:

targeted advertising,

without independently establishing a lawful basis and satisfying GDPR requirements.

Similarly, data collected for grid balancing may not automatically be available for unrelated commercial profiling.

The principle therefore requires electricity companies to identify why data are being collected before determining how much data should be collected.

7. Data Minimisation

Data minimisation requires personal data to be:

adequate, relevant and limited to what is necessary.

This creates an important regulatory issue for smart grids.

A system operator might technically be able to obtain electricity consumption every minute. That does not necessarily mean that minute-by-minute data are legally necessary for every purpose.

For example:

The EU's smart-metering framework specifically encourages anonymisation and limitation of collection and retention where possible. (EUR-Lex)

8. Transparency and Consumer Information

Article 13 GDPR is important when electricity companies collect personal data directly from customers.

Consumers should receive understandable information concerning matters such as:

identity of the controller;

purposes of processing;

legal basis;

categories of data;

retention;

recipients;

rights of the data subject;

complaint mechanisms; and

relevant automated decision-making.

This is particularly important when smart meters are installed because consumers may not appreciate the extent of information that can be derived from high-frequency electricity consumption.

The current Netz Niederösterreich case, C-468/24, illustrates this issue directly. The Austrian reference asks the CJEU to examine the interaction between smart-metering rules and GDPR Articles 5, 13 and 32, including information concerning access to customer data outside the ordinary reading interval. (EUR-Lex)

9. Security of Electricity Data

Article 32 GDPR requires appropriate technical and organisational measures to ensure data security.

Electricity systems create particular cybersecurity risks because data may move through:

Smart meter → communications network → DSO → supplier → aggregator → market platform

Security failures can potentially expose:

consumption patterns;

customer identities;

billing information;

location-related information; and

operational information.

The electricity sector therefore requires both energy-system cybersecurity and personal-data security.

Security measures can include:

encryption;

authentication;

access controls;

pseudonymisation;

network segmentation;

logging;

incident-response procedures;

vulnerability management; and

appropriate retention and deletion controls.

10. GDPR and Electricity Market Competition

GDPR also has an indirect competition dimension.

Modern electricity markets increasingly depend upon access to consumer data.

For example, an aggregator may need consumption information to provide:

demand response;

flexibility services;

virtual power-plant services;

distributed-energy optimisation; or

dynamic pricing.

If an incumbent supplier possesses detailed customer data while competitors cannot access equivalent information, data governance can become relevant to market access.

However, GDPR does not create a general right for competitors to obtain another company's customer database.

Instead, electricity regulation and data-protection law must operate together.

11. Data Portability

Article 20 GDPR provides a right to data portability in qualifying circumstances.

This can support consumer mobility in electricity markets.

For example, customers may increasingly want to transfer consumption information to:

a new supplier;

an energy-management service;

an aggregator;

an energy-efficiency provider; or

another digital energy platform.

The EU electricity framework also promotes consumer access to energy data and interoperability. The broader energy framework therefore links consumer participation in electricity markets with appropriate access to metering information. (InfoCuria)

Data portability must nevertheless be distinguished from unrestricted disclosure of all information held by an electricity company.

12. Automated Decision-Making and Electricity Markets

Article 22 GDPR may become relevant where automated processing produces legally significant or similarly significant effects.

Potential electricity-sector applications include:

automated credit assessment;

automated fraud detection;

automated customer classification;

automated pricing decisions;

automated eligibility decisions;

automated demand-response participation; and

algorithmic energy-service decisions.

Where Article 22 applies, additional safeguards become relevant.

Electricity regulators therefore increasingly need to consider not only whether an algorithm works, but also:

What personal data does the algorithm use, for what purpose, and what consequences does its decision have for the consumer?

13. GDPR and Demand Response

Demand response allows consumers or aggregators to modify electricity consumption in response to:

prices;

grid conditions;

renewable generation;

congestion; or

system-balancing requirements.

Such systems may require detailed consumption information.

Consequently, the regulatory design should distinguish between:

Necessary operational data

Information genuinely required to operate the demand-response mechanism.

Optional behavioural profiling

Information used to develop detailed profiles of customers.

The first may be justified by contractual, statutory or other lawful bases, while the second requires separate analysis under GDPR.

14. GDPR and Distributed Energy Resources

Distributed energy resources include:

rooftop solar;

batteries;

electric vehicles;

heat pumps;

smart appliances; and

flexible loads.

These technologies create large quantities of data.

For example, an EV charging platform may know:

when a vehicle charges;

how frequently it charges;

approximate location;

charging duration;

energy consumed; and

customer account information.

Combining such datasets can produce a detailed behavioural profile.

Therefore, GDPR compliance must increasingly be incorporated into distributed-energy regulatory design, rather than treated merely as an administrative privacy issue.

15. Important Case Law

15.1 Deutsche Wohnen SE v Staatsanwaltschaft Berlin — C-807/21

The CJEU's Grand Chamber judgment of 5 December 2023 concerned GDPR enforcement, controllers and administrative fines. (EUR-Lex)

Importance for electricity markets

Electricity companies are typically corporate entities. The case is therefore relevant to the question of how GDPR liability can attach to companies that process large volumes of customer information.

It reinforces the importance of:

identifying the controller;

implementing GDPR compliance systems;

understanding responsibility for processing; and

maintaining appropriate organisational controls.

The case is not an electricity-specific judgment, but its principles are highly relevant to electricity suppliers, DSOs and other energy companies.

15.2 Pankki S — C-579/21

In Pankki S, the CJEU addressed the scope of access to personal data and the concept of personal data.

The Court reiterated the broad scope of personal data, including information resulting from processing that relates to an identified or identifiable person. (EUR-Lex)

Electricity-market relevance

The principle can apply to:

customer consumption histories;

system-generated customer information;

access logs;

meter identifiers; and

information derived from electricity databases.

An electricity company cannot necessarily avoid GDPR simply because information was generated automatically by a technical system.

15.3 SR v Netz Niederösterreich GmbH — C-468/24

This is particularly important because it directly concerns smart meters and electricity consumption data.

The Austrian court referred questions concerning:

smart-meter installation;

consumer refusal of smart meters;

electricity consumption data;

data-security requirements;

GDPR Articles 5, 13 and 32;

consumer information; and

interaction between electricity-market legislation and privacy law. (EUR-Lex)

The reference demonstrates that smart-meter regulation cannot be considered independently from GDPR and fundamental privacy rights.

As of the sources reviewed here, the case is a pending CJEU reference, rather than a final judgment on the merits. (EUR-Lex)

15.4 Planet49 — C-673/17

In Planet49, the CJEU considered the validity of consent involving a pre-checked checkbox in the context of cookies.

The case establishes an important principle concerning genuine, active consent.

The principle is relevant to electricity platforms where consent is used for optional processing. A consumer should not be treated as having provided valid consent merely because an operator has made consent the default and requires the consumer to opt out. The smart-meter litigation discussed in C-468/24 expressly raises this type of issue. (curia)

16. Relationship Between GDPR and Electricity Directive 2019/944

GDPR does not operate in isolation.

The EU electricity-market framework under Directive (EU) 2019/944 contains provisions concerning:

smart metering;

consumer access to information;

data management;

electricity-market participation; and

protection of consumer information.

Article 23 is particularly important because it addresses data processing and administration in the electricity market and expressly connects electricity-sector data management with the GDPR. (EUR-Lex)

This produces a dual regulatory framework:

Electricity law determines what data may be needed for electricity-market functioning, while GDPR determines how personal data must be processed.

17. Role of Data Protection by Design

Article 25 GDPR introduces data protection by design and by default.

For electricity-market infrastructure, this means privacy should be incorporated at the design stage.

For example:

Poor regulatory design:

Collect maximum smart-meter data first and determine privacy safeguards later.

Privacy-by-design approach:

Determine the regulatory purpose → identify minimum necessary data → pseudonymise where possible → establish access controls → define retention → implement security → provide consumer transparency.

This is particularly important when designing:

smart meters;

smart grids;

flexibility markets;

energy-data hubs;

EV charging platforms;

distributed-energy platforms; and

automated demand-response systems.

18. Data Protection Impact Assessments

A Data Protection Impact Assessment (DPIA) may be required where processing is likely to result in a high risk to individuals.

Smart-meter systems can potentially involve:

systematic monitoring;

large-scale processing;

detailed behavioural information; and

technologically complex data infrastructures.

The EU's earlier smart-metering framework specifically encouraged impact assessments before large-scale smart-meter deployment. (EUR-Lex)

A DPIA should examine:

What data are collected?

Why are they collected?

Who controls the data?

Who receives the data?

How long are they retained?

What risks arise?

Can the data be minimised?

Can anonymisation or pseudonymisation be used?

What security measures are required?

What rights do consumers have?

19. Anonymisation and Pseudonymisation

These are particularly valuable in electricity markets.

Anonymisation

Data are processed so that individuals can no longer reasonably be identified.

Example:

Aggregate electricity consumption of 10,000 households in a region.

Pseudonymisation

Identifiers are replaced with pseudonyms, but re-identification remains possible with additional information.

Example:

Customer ID X74291 rather than the customer's name.

Pseudonymisation is therefore a security and risk-reduction technique, but it does not automatically remove data from the GDPR's scope.

The EU's smart-metering recommendations encourage anonymous or pseudonymous approaches where possible. (EUR-Lex)

20. GDPR and Energy Data Governance

A modern electricity market therefore requires an integrated data-governance model.

Layer 1 — Energy law

Determines:

market operation;

metering;

balancing;

settlement;

supplier switching;

system operation.

Layer 2 — GDPR

Determines:

lawful processing;

transparency;

minimisation;

consumer rights;

security;

retention;

accountability.

Layer 3 — Cybersecurity

Protects:

meters;

networks;

communication infrastructure;

databases;

control systems.

Layer 4 — Competition law

Addresses:

data access;

market power;

discriminatory access;

consumer switching;

competitive neutrality.

These regimes increasingly overlap.

21. Regulatory Challenges

Several major challenges arise.

1. High-frequency consumption data

More granular data can increase system efficiency but also increase privacy risks.

2. Multiple data controllers

A single customer may interact with:

DSO + supplier + aggregator + energy platform + EV operator.

Determining who is controller, processor or joint controller can become complex.

3. Data sharing

Electricity markets require extensive data sharing, but GDPR requires a lawful and appropriately limited basis.

4. Artificial intelligence

AI systems can derive additional information from consumption datasets, creating new profiling risks.

5. Cybersecurity

A cyberattack can simultaneously become:

an electricity-system incident; and

a personal-data breach.

6. Consumer consent

Regulators must distinguish genuinely optional processing from data processing required for electricity-market functions.

22. Legal Principles Emerging from the Case Law

The combined GDPR jurisprudence supports several principles relevant to electricity markets:

Electricity consumption information can constitute personal data.

The concept of personal data is interpreted broadly.

Technical or automatically generated information can still be personal data.

Controllers must identify an appropriate lawful basis.

Consumers require meaningful transparency.

Consent must be genuine where consent is the chosen legal basis.

Data collection should be proportionate to the purpose.

Security must be integrated into electricity-data systems.

Corporate entities can face GDPR enforcement and fines.

Smart-meter regulation must be interpreted consistently with data-protection rights.

23. Conclusion

The application of GDPR to electricity markets represents a shift from viewing electricity data merely as technical market information toward recognising it as potentially sensitive information about identifiable individuals.

Smart meters, dynamic tariffs, demand response, distributed energy resources and digital electricity platforms all depend upon increasingly granular datasets. Consequently, electricity-market regulation must reconcile two objectives:

efficient, data-driven electricity markets
and protection of consumers' fundamental data rights.

The most important legal principle is that electricity-market efficiency does not eliminate GDPR obligations. Electricity companies and regulators must determine the lawful purpose for processing, minimise data collection, ensure transparency, protect information through appropriate security measures, establish appropriate retention periods and provide applicable data-subject rights.

The pending Netz Niederösterreich (C-468/24) reference is especially significant because it places smart-metering, electricity-market regulation, GDPR and fundamental privacy rights directly before the CJEU. (EUR-Lex)

Accordingly, GDPR should be understood not as an external compliance requirement imposed upon electricity markets, but as an increasingly important component of the legal architecture of the digital electricity system.