ElWG: Quarter-hourly Values in Austria

On December 11, 2025, the Austrian parliament passed the Elektrizitätswirtschaftsgesetz (ElWG — Electricity Industry Act) — and reset the data foundation of the Austrian energy market. One of the most far-reaching changes concerns Viertelstundenwerte (quarter-hourly meter readings): they are moving from opt-in to default. For energy service providers, building managers, and software developers, this opens up a data landscape that was previously available only to a fraction of market participants.

This article explains what has changed, the numbers behind it, and what it means for companies working with energy data.

Note: This article explains the underlying shift to quarter-hourly values. For the additional ElWG rules that took effect from 1 April 2026 — including dynamic tariffs, SNAP, and the upcoming key dates — see our overview ElWG from 1 April 2026: What changes for businesses.

What has changed? The ElWG at a glance

The paradigm shift: From opt-in to opt-out

Until now, Austria operated an opt-in model for Viertelstundenwerte (quarter-hourly readings). If a consumer wanted their smart meter to record and transmit electricity consumption in 15-minute intervals, they had to actively request it from their grid operator. Those who did nothing received hourly values — quarter-hourly readings required an active opt-in.

The new ElWG reverses this principle. Quarter-hourly readings are now the legal default for all smart meters in Austria.^[1] Customers who do not want this must actively opt out.^[2] The barrier no longer lies in activating the feature but in deactivating it.

Before: No action taken = no quarter-hourly data. After: No action taken = quarter-hourly data runs automatically.

However, "legal default" does not mean "immediately active everywhere." The law defines a transition period during which grid operators may continue transmitting daily values for certain metering points. Anyone planning around the switch needs to understand these phases.

Transition timeline: When does the new standard take effect?

§ 54 (3) ElWG grants grid operators a transition period during which they may continue transmitting daily energy values instead of quarter-hourly readings for certain metering points:^[3]

• Until 31 December 2026: for metering points with annual consumption of up to 5,000 kWh — provided none of the exceptions listed below apply.
• From 1 January 2027: only for metering points with annual consumption of up to 1,500 kWh.

A typical Austrian household consumes around 3,500–4,000 kWh per year. For the majority of "ordinary" households, the practical switchover deadline is therefore 1 January 2027.

Additionally, the regulator (E-Control) may extend these deadlines for grid operators that had achieved at least 70% smart meter penetration by 31 December 2019 — so-called first movers — if they can demonstrate technical or economic disproportionality (§ 54 (4)).^[4] This means: even the 2027 deadline is not fully guaranteed in every grid area.

Who gets quarter-hourly data first?

The transition period under § 54 (3) does not apply to all metering points. The law explicitly excludes certain groups from the exception — they therefore receive quarter-hourly data from the start, regardless of their annual consumption:^[3]

• Metering points with dynamic electricity price contracts (§ 22 ElWG)
• Feed-in via direct lines or prepayment meters (§ 29 ElWG)
• Metering points with heat pumps, charging stations, energy storage, or generation plants
• Participants in shared energy use models^[5] (e.g. energy communities)

These groups receive quarter-hourly data not because grid operators choose to prioritize them, but because the law denies them the transitional daily-value exception. The outcome is the same — these metering points are switched first — but the driving force is the legislation, not an operational decision by grid operators.

The numbers: Why this is a turning point

6.53 million smart meters — and only 12.6% with quarter-hourly data until now

Austria has largely completed its smart meter rollout. The figures from E-Control (as of end-2024) are clear:

• 6.74 million metering points fall under the rollout obligation
• 6.53 million (96.9%) already have a smart meter installed
• 6.06 million (94%) are network-connected — meaning they actively transmit data

Of these 6.53 million smart meters, only around 760,000 had quarter-hourly readings activated. That is approximately 12.6%. The reason: the opt-in model presented a high barrier. Many consumers were not even aware the option existed, or saw no immediate benefit in enabling it.

What this means for data availability

With the switch from opt-in to opt-out, the starting position changes fundamentally. Instead of 760,000 meters with quarter-hourly data, over 6 million metering points will be covered once the transition period concludes — expected from 2027 onward. That is a jump from 12.6% to potentially over 95% of all metering points.

The path there is phased: metering points with generation plants, heat pumps, and energy community participation are switched first, followed by most households with up to 5,000 kWh annual consumption by end of 2026, with the threshold dropping to 1,500 kWh from 2027. The 6-million mark is not an immediate effect but the result of a staged ramp-up through 2026 and 2027.

For the Austrian energy market, this means: quarter-hourly readings are no longer a niche product but are becoming a comprehensive data standard. Austria is becoming one of the most data-rich energy markets in Europe at the consumer level.

For more on smart meters in Austria, see our Smart Meter Guide.

Sommer-Sonnenrabatt: The first tangible use case

One of the most tangible innovations of the ElWG is the Sommer-Sonnenrabatt (Summer Sun Discount): a 20% reduction on grid usage fees, applicable from April to September, between 10:00 and 16:00.^[6]

The logic behind it: during summer months, PV systems produce more electricity around midday than the grid can absorb. The discount is intended to motivate consumers to shift their consumption into exactly these hours — for example by charging electric vehicles, running heat pumps, or starting washing machines and dishwashers.

Prerequisite for the discount: quarter-hourly data must be available. Without 15-minute readings, there is no way to verify that consumption actually occurred during the eligible time window. The Sommer-Sonnenrabatt is therefore also a financial incentive for end customers to keep the default setting active.

For energy service providers, this creates a concrete opportunity: proactively inform customers about the discount, recommend consumption shifts, and make the actual value of quarter-hourly data visible.

Third-party data access: New rules in effect since April 2025

Authorized third parties automatically receive the finest granularity

Since April 2025, another important regulation applies: when an end customer grants a third-party provider access to their smart meter data, the provider automatically receives the finest available resolution.^[7] If the meter has quarter-hourly readings activated, the third party receives quarter-hourly data. A separate opt-in for granularity is no longer required.

This considerably simplifies data access. A single consent is sufficient to receive the best possible data quality. For API users, this means: the data delivered through the EDA infrastructure already arrives at the finest available resolution.

The EDA process: How data sharing works technically

Data sharing with third parties runs through the EDA network (Energiewirtschaftlicher Datenaustausch — Energy Data Exchange). The process is standardized but technically complex:

1. The service provider submits a consent request via the EDA network to the responsible grid operator.
2. The end customer confirms the data release through their grid operator's portal.
3. After confirmation, daily data delivery (T-1) to the service provider begins.

The challenge lies in the fragmentation: over 140 grid operators in Austria, each with their own infrastructure and portal, some with different response times. Communication runs via the AS4 protocol, encrypted and certificate-based. For a single company, building and maintaining a direct EDA connection means substantial effort.

What does this mean for your business?

The combination of widespread quarter-hourly data and simplified third-party access opens up concrete business opportunities. What is relevant depends on your industry.

Energy service providers and utilities

With quarter-hourly readings as the default, a range of products and services becomes viable that previously failed due to limited data availability:

• Dynamic and time-variable tariffs — Pricing models that account for actual consumption timing require granular measurement data. With 15-minute values as standard, such tariffs can be offered across the board.
• More accurate load forecasting — Quarter-hourly resolution substantially improves forecasting quality. This directly affects procurement costs and balancing group management.
• Consumption optimization as a service — Show customers when they consume how much electricity, and provide concrete savings recommendations. What's concretely possible with quarter-hourly data is illustrated in five practical examples.

More on our page for energy service providers.

Building managers and facility management

For commercial properties and larger building portfolios, quarter-hourly data represents a step change in energy management:

• Continuous monitoring on a 15-minute basis — Consumption can be analyzed not just monthly but throughout the day. Anomalies and load peaks become visible before they impact the annual bill.
• Identifying optimization potential — When are HVAC systems running at full load? Is there consumption outside operating hours? 15-minute data answers these questions.
• Evidence for ESG reporting and energy audits — Granular, auditable consumption data simplifies documentation for investors and regulators. See our guide on what energy data EEffG and CSRD actually require.

More on our page for building management.

Software developers and product teams

For teams building energy products, the new data availability solves a core problem: the lack of access to standardized, granular consumption data.

• Standardized data source — Instead of proprietary integrations or manual data collection, there is now a broad base of 15-minute data retrievable through the EDA network.
• No need to build your own infrastructure — Directly connecting to over 140 grid operators is complex and maintenance-intensive. Platforms that abstract this complexity enable faster market entry.

More on our page for developers.

How to use quarter-hourly data — in practice

The challenge: over 140 grid operators, one fragmented infrastructure

Data availability alone is not enough. Having over 6 million meters deliver quarter-hourly readings after the transition completes is of little use if accessing that data is technically demanding. And it is.

Austria has over 140 distribution grid operators. Each runs its own infrastructure, and some have their own response times and particularities in implementing the EDA standard. Communication runs via regulated protocols (AS4), not standard REST APIs. Anyone who wants to connect directly needs specialized software, certificates, and continuous monitoring.

For most companies, the overhead simply isn't worth it — especially when energy data is one component of a larger product rather than the core business. For a deeper look at this challenge, see our article on why you should automate smart meter data.

energiedaten.at: One API for all metering points

energiedaten.at is a B2B SaaS platform that provides access to Austrian smart meter data through a unified interface. The platform connects to all Austrian grid operators via the EDA network and handles the full technical complexity: protocol communication, consent management, data validation, and normalization.

Instead of dealing with over 140 different grid operator systems, you receive data through a single API — as JSON, via webhook, or as CSV. The previous day's consumption data is available daily (T-1).

Information on features and pricing is available on our pricing page.

Outlook: What comes next?

The ElWG sets the regulatory framework. The transition proceeds in stages through 2027. Metering points with generation plants, heat pumps, and energy community participation are excluded from the transition period and will be switched first. Most households follow by end of 2026, and from 2027 the standard applies practically across the board.

In parallel, the new market roles defined by the ElWG will gain importance: aggregators bundling generation and loads; flexibility service providers coordinating grid congestion and balancing; organizers managing shared energy use. All of these roles depend on granular consumption data.

The business models built on quarter-hourly data are just beginning. Dynamic tariffs, load optimization, predictive maintenance, automated ESG reporting — the data foundation is being laid right now. Companies that engage with the data infrastructure today will have a head start when quarter-hourly readings become universally available.

Frequently asked questions

What are Viertelstundenwerte (quarter-hourly readings)?

Viertelstundenwerte are electricity consumption measurements recorded every 15 minutes. A smart meter with quarter-hourly readings activated produces 96 data points per day (24 hours × 4 intervals). This resolution enables load profile analysis, attribution of consumption to specific times of day, and forms the basis for time-variable tariffs. Without quarter-hourly readings, a smart meter typically delivers hourly values.

Do I need to do anything as a customer?

No. Under the new ElWG, quarter-hourly readings become the default automatically. If you already have a smart meter, the quarter-hourly recording will be activated in stages. Metering points with PV systems, heat pumps, or energy community participation are excluded from the transitional period and will be switched first. For most other households, the switch takes effect by end of 2026 (up to 5,000 kWh annual consumption); from January 2027 the threshold drops to just 1,500 kWh. If you do not want this, you can actively opt out through your grid operator. For most consumers, there is no reason to do so: the data enables the Sommer-Sonnenrabatt (Summer Sun Discount) and other benefits.

How do I get access to quarter-hourly data as a business?

As an authorized third party, you gain access through the EDA network. The end customer must consent to data sharing via their grid operator's portal. Once consent is granted, data is delivered daily (T-1). You automatically receive the finest available resolution — meaning quarter-hourly data, provided it is activated on the meter. Alternatively, you can use platforms like energiedaten.at that handle the EDA connection and provide data through a standardized API.

What is the Sommer-Sonnenrabatt (Summer Sun Discount)?

The Sommer-Sonnenrabatt is a 20% reduction in grid usage fees, applicable from April to September, between 10:00 and 16:00. It is designed to motivate consumers to shift their electricity consumption to the sun-rich midday hours, when PV generation is at its peak. Prerequisite: quarter-hourly data must be available at the metering point so that consumption can be attributed to specific time windows.

[1] ElWG, BGBl. I Nr. 91/2025, § 54 (1): Quarter-hourly values as the legal default for all smart meters.

[2] ElWG, § 54 (2): Right to opt out of quarter-hourly value transmission.

[3] ElWG, § 54 (3): Transitional provision — grid operators may transmit daily energy values: until 31.12.2026 for annual consumption ≤ 5,000 kWh, from 1.1.2027 only for ≤ 1,500 kWh. Excluded are metering points with dynamic tariffs (§ 22), direct-line feed-in or prepayment (§ 29), heat pumps, charging stations, storage, generation plants, and participants in shared energy use.

[4] ElWG, § 54 (4): Extension possibility for grid operators with ≥ 70% smart meter penetration by 31.12.2019, upon demonstrating technical or economic disproportionality.

[5] ElWG, §§ 66–72: Provisions on shared energy use (energy communities). Entering into force 1 October 2026 per § 188 (3).

[6] ElWG, § 128 (3): Framework for time-variable grid usage fees (basis for the Sommer-Sonnenrabatt).

[7] ElWG, § 58: Data access for authorized third parties — automatic transmission at the finest available resolution.