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Security of the electricity supply and blackout prevention

Electricity supply - a responsibility to society

Austrian Power Grid (APG) has a legal and thus a social mandate, namely to provide Austria with a reliable supply of electricity. Assisted by its high-calibre workforce, APG secures the electricity supply from Lake Neusiedl to Lake Constance. Austria’s electricity supply is founded on a robust, high-capacity power grid, a power plant mix comprising numerous wind, hydro and pumped storage power plants, supplemented by reserve power plants. There is also continuous close coordination with other national grid operators and international transmission system operators.  

Electricity stress test for the security of supply in winter 2022/23

In the fall of 2022 APG conducted an electricity stress test with the aim of identifying critical situations that could lead to possible intermittent power shortages (demand for power exceeds supply of power). This facilitated a more targeted monitoring of the supply situation during the winter and, in the event of an escalation, an advance warning with regard to emergency intervention measures.

In this stress test a number of specific factors (electricity consumption, availability of power plants, etc.) were evaluated in individual and combined scenarios. Since Austria is an electricity importing country, especially in the winter, the conditions in the power industries of its neighboring countries are elementary.

Result: Overall, the energy situation for the winter can be described as challenging but manageable. In the most probable scenario (combined scenario), the simulations show manageable challenges with respect to the power supply in Austria. No supply shortage could be identified at any hour. In the other two scenarios supply shortages of up to 815 hours are possible – but these can be compensated with appropriate preventive measures and monitoring. However, in the event of additional critical events or unexpected new general conditions Austria might face bigger challenges requiring statutory measures in terms of interventions in the energy system. This also applies if the countermeasures initiated in scenarios two or three are not effective.

Forecasts concerning the winter 23/24 cannot be made on the basis of this stress test.

None of the scenarios identified an increased blackout risk.

Reliable supply for a sustainable future

In our modern, sustainable and digital world, electricity is the backbone of society, business and industry. As all of these areas become more electrified and decarbonised, demand for electricity will grow even further. In this transformation away from carbon-rich and towards carbon-neutral energy sources, security of the electricity supply is fundamental for all areas of life and economic activity. Reliability of supply in Austria has now reached 99.99 per cent – a world record. The frequency disturbance (not to be confused with a blackout) that occurred at 2:04 p.m. on 8 January 2021 was the most recent critical incident, which thanks to the excellent European collaboration went largely unnoticed by most of the population. Normal operations were restored in just over an hour, at 3:08 p.m. precisely. 

Regular drills

The handling of critical energy situations (including equipment malfunction and protracted or unexpected specific weather conditions) is practised in regular drills. As a result, Austria now boasts reliability of supply of 99.99 per cent – a world record. 

Over the coming years, a coordinated plan will be needed to manage the transformation of the electricity system, along with action to increase capacity across power grids, storage, production and reserves and to integrate new players by way of digital platform technologies. With its investment programme of around €3.5bn for the period to 2031, APG will be key to ensuring that this very transformation is a success. 


A blackout or a regional power failure?

Potential for confusion

A clear distinction needs to be made between blackouts and local or regional power failures. In Austria, for example, interruptions to the power supply are commonplace in the Alpine regions, in particular, as a result of extreme weather conditions during the winter months. 

Security of the electricity supply - FAQs

What exactly is a blackout?

A blackout is an unexpected, large-scale, trans-regional power failure – irrespective of duration. Pursuant to the legal mandate, the Austrian transmission system operator – Austrian Power Grid (APG) – is responsible for fixing such outages. In addition, APG has general responsibility for ensuring a reliable electricity supply in Austria in coordination with distribution system operators and other players into the electricity system.  

How reliable is Austria’s electricity supply?

With power grid availability at over 99.99 per cent, Austria’s security of supply ranks among the best in the world. Good coordination processes among the grid operators at a national and international level and the solid power plant mix in Austria are essential components of this reliability. Security of the electricity supply is the basis of our modern, sustainable and digital society. In the course of the transformation of the energy system, action to further increase the capacity of the grid, storage facilities, reserve power plants and sustainable production and to integrate all new players into the energy system by way of digital platform technologies is necessary to maintain this high quality of supply security for business and society. This is why APG is investing €3.5bn in upgrading and expanding the power infrastructure over the next ten years. 

How likely is Austria to experience a blackout in the near future?

The risk of a blackout has undoubtedly increased in recent years (due to cyber crime, for instance). That said, a fundamental requirement of APG’s operations management is that it can handle unforeseen crisis situations and each isolated event does not pose a blackout risk. This is the reason why operations management always plans for a failure of key equipment (n–1 security). A large-scale power failure can therefore only take place if unforeseen or irrecoverable events occur in close proximity to each other in terms of both time and technology. 

What steps does APG take to avoid blackouts?

APG takes a range of preventive measures to avert the growing risk of a blackout. APG’s social mandate is to guarantee a reliable supply of electricity for all residents of Austria. This is ensured by highly qualified, trained staff and very well thought-out, tried-and-tested national and international operations management and safety plans, supplemented by periodic training on simulators and routine emergency drills conducted in conjunction with all relevant players in the energy system at a national and international level. 

How long does a blackout last and what costs may be incurred?

The regular simulations and emergency drills performed show that APG is capable of putting the electricity grid back into operation within 12 to 48 (or even 10 to 24) hours, thus restoring security of the electricity supply. This is achieved by starting up power plants with what is referred to as black-start capability (for example, pumped storage power plants) with which operational islands are created and then combined. 

Several years ago, the Energy Institute at the Johannes Kepler University in Linz conducted a study to calculate the damage caused by a nationwide power failure. The blackout simulator used by the scientists determined ta daily cost of around €1.2bn. Direct link to the blackout simulator

What is APG’s role in the Energy.21 blackout exercise?

APG is part of the Energy.21 blackout exercise organised by the state of Tyrol and the Austrian Ministry of the Interior. APG draws on its expertise and its statutory role as a transmission system operator for this crisis drill, which practices the emergency response to an electricity shortage caused by a prolonged cold snap. 

How safe is the power grid from hacker attacks?

Digitalisation extends to all areas of the company and entails numerous measures that will be implemented at various levels. These include security screening of personnel, specific restrictions on the use of information technology, and continuous monitoring of digital platforms for possible vulnerabilities. APG is part of the critical infrastructure, which is why it is constantly exchanging ideas and information with the relevant authorities and ministries, such as the Federal Ministry of the Interior’s Cyber Security Center. Furthermore, it is integrated into the main Austrian platforms in this field, as a member of Austrian Energy CERT, for example. For years, voluntary certification to ISO 27001/27019 has confirmed APG’s ongoing efforts in this area, which are also certified through the recently enacted Network and Information System Security Act (Netz- und Informationssystemsicherheitsgesetz, NISG). 

In addition, APG took steps to further strengthen cyber security that go beyond the certification requirements. For instance, a dedicated Security Operations Center is responsible 24/7 for detecting attacks, responding to them and continuously improving the level of cyber security. In addition, our employees regularly receive automatic notifications of and training in cyber security threats.

How big is the risk that a prolonged cold snap will lead to a power failure in Austria?

This is always a risk under extreme conditions, but the excellent power plant mix in Austria helps us to avoid such a situation. As things stand today, the likelihood is therefore low. 

How well prepared is Austria for an electricity shortage?

If consumption in Austria can no longer be fully met through power plant feed-ins and imports, the requirements under the Austrian Energy Intervention Powers Act (Energielenkungsgesetz, EnLG) enter into force. Following due coordination with the Ministry, E-Control and the federal states, contingency measures can be taken from rationing electricity to major consumers to cutting off supplies to entire areas. However, such measures are only necessary in an extreme emergency. The Energy Intervention Powers Act (EnLG) legitimises these measures in Austria (following the issuance of a corresponding Regulation on Measures by the Federal Ministry) such that they cause the least possible damage and impact on society and the business community. 

What is the function of power lines in blackout prevention?

Upgrading and expanding the electricity infrastructure and utilising state-of-the-art technologies are key factors in security of the electricity supply: we will only have the reserves we need in the event of a future crisis if appropriate line capacities are available in Austria. This is the reason why projects like the Salzburg line are particularly important. In 2021 alone, APG invested around €357m in the expansion and modernisation of the transmission grid – rising to €3.5bn over the next ten years. 

However, along with a high-performance electricity grid, we also need appropriate storage facilities, sufficient production capacities, and use of digital technologies in order to make any potential flexibility options of businesses and in the industrial sector available for system services. APG is a frontrunner here with several research projects being implemented with partners at a national and international level. All of these measures not only serve to ensure a reliable electricity supply, they are also necessary to sustainably launch the energy transition and the electrification of society, business and industry. 

Completion of the 380-kV ring would increase reliability. How is this progressing?

The Salzburg line is the key project for this. It will create sufficient capacity to safeguard Salzburg’s electricity supply, integrate Austria’s renewable energy and use electricity from Europe cost-effectively for Austria’s businesses and residents. APG is investing €890m in this project, which will create around 7,000 jobs in Austria and directly safeguard some 2,250 jobs in the state of Salzburg. This is an important driver of economic growth, especially in times of crisis. Following a delay of around 3.5 years owing to procedures, APG started construction work on the country’s most important electricity infrastructure project in October 2019 on the basis of a legally binding permit and its statutory obligation. Construction has been progressing on schedule along the entire route for a year now. There must be no delay in the structural implementation of the Salzburg line if the goals of the energy transition and the electrification of society, business and industry are to be achieved. The Salzburg line is due to go into operation in 2025. 

Regarding the frequency disturbance that occurred in the European power grid in January 2021, what happened and how serious was it?

From an energy management standpoint, at the time the incident occurred there were very strong load flows from Southeastern Europe towards Central and Western Europe. The pan-European frequency disturbance on 8 January 2021 was caused by the tripping of a busbar coupler in the Ernestinovo substation, an important distribution node in Croatia with transnational connections to neighbouring countries. This provoked a cascade of outages in several countries across this region. 

South-east of Austria, the continental electricity grid was split into two frequency zones (“synchronous islands”). In the western island, which included Austria, the drop in frequency (which means too little electricity is generated) was briefly as high as about 260 MHz. 

When this happens, the automated protection mechanisms coordinated throughout Europe are activated: in Austria, for example, in addition to activation of the frequency containment reserve, additional production was injected into the system to halt the drop in frequency. Electricity supplies to targeted, individual consumers in Italy and France were reduced. After that, the national system operators across Europe agreed on manual measures to bring the frequency back to 50 Hz and to synchronise the two separate frequency zones. Normal operations were able to be resumed after an hour. 

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There are also many flexibility options and opportunities for grid stabilisation at a regional level, for example through rapid adjustment of production or even purchases of flexible electricity. Which mix of measures is suitable for this?

We believe that the use of additional, partly small-scale flexibility options at a regional and trans-regional level will be of major importance in future. However, these new customer groups and suppliers can only be captured efficiently using digital platforms (e.g. crowd balancing platforms). These enable small-scale potential to be made visible and offered as system services for the transmission system operator’s flexibility management. APG is working very hard at an Austrian level to find solutions with the distribution system operators but also with representatives of industrial sector and the business community. At an international level, APG is part of Equigy, a crowd balancing platform that integrates the small-scale players into balancing energy markets as well as redispatching. However, the complete digitalisation of all players in the electricity system is a prerequisite for all of these smart solutions. It is precisely in this area that APG is blazing a trail with innovative system solutions. 

In addition, it is important to leverage the potential of sector coupling and electricity storage. Only a mix of all these instruments together with a high-performance power grid will ensure that Austria’s electricity supply is not only reliable, but also sustainable. 

Which tools are used to ensure security of the electricity supply?
  • European electricity system: The European electricity system regulates pan-European coordination of (n–1) secure grid operation as well as the maintenance of reserves of power plant capacities coordinated between TSOs. In the event of a fault, balancing services are activated automatically in each country or control area via this pan-European coordinated system so that the fault can be rectified as a joint effort. The balancing services thus spread across Europe can be used in particular to balance out fluctuations in frequency (based on the concept of “distributed resilient security islands”; pan-European frequency containment reserve: 3,000 MW, Austria’s share is currently +/- 71 MW). 

  • Holistic system planning: Transmission system operators use the ENTSO-E’s Ten Year Network Development Plan (TYNDP) as a tool for forward-looking modelling and analysis of the European electricity system. The scenarios focus in particular on the need for trans-regional grid expansion in order to integrate renewables and on the further development of the internal market. To optimise the use of existing infrastructure, but also to make the transformation to a sustainable energy system as cost-effective and sustainable as possible, it is necessary to plan the energy system holistically (especially in terms of grid, storage, digital, transport, industry and heat aspects). Decarbonisation by means of renewable electricity increases the cachet of the electricity sector. APG has a pivotal role to play here. 

  • Grid upgrades and expansion: The availability of capacities is key to both a secure supply of electricity and rapid integration of renewables into the grid. The more efficient the power grids are, the more renewable energy can be integrated and used in connecting grids across Europe, or cheaper electricity can be made available. Not only is it crucial to build new power lines swiftly, but existing lines, some of which have been in existence for up to 70 years, must also be modernised. Grid expansion has a vital role to play in connection with the present climate targets, future renewable energy output and other electricity-based developments (especially electromobility and industrial processes). New innovative technologies in the fields of storage, sector coupling and flexibility will supplement grid expansion. Over the next ten years (from 2022 to 2035), APG will invest around €3.5bn in expanding and modernising the grid infrastructure; capital expenditure in 2020 alone came to around €360m. 

  • Rapid implementation of key projects: The existing grid projects from APG’s Network Development Plan must be implemented in practice without delay. These include, in particular, grid expansion at the 380-kV and 220-kV level, but also projects for connecting renewable electricity generation (especially hydropower, PV and wind power) to the grid and for electricity storage (including P2X pilot plants). 

  • Grid reserve: To be able to continue to operate the power grid reliably (despite delays in grid expansion), APG needs to intervene in the generation schedules of power plants (and in some cases of consumers) or adjust the planned utilisation of power plants. It does this by starting up (or scaling back utilisation of) reserve power plants (“grid reserve”) to reduce the strain on the grids. The grid reserve guarantees the availability of required capacity reserves (power plants) so that they can be used to prevent the grid from becoming overburdened. This was necessary on 261 days in 2020, giving rise to costs of around €134m; a “New Grid Reserve” was adopted by the Austrian Parliament in December 2020. 

  • Common Grid Model (CGM): The number of players in the energy system will rise sharply in the energy system of the future; in particular, decentralised small-scale generation (wind, hydro and solar) will rise. To ensure grid security, it is therefore necessary that the data of all these players (consumers, power plants, etc.) is mutually exchanged and made available for grid security calculations. In particular, this data must also represent the generation or the reference to the respective node in real time. The concept for this has already been agreed within the Austrian energy industry. The ECA is expected to issue a corresponding regulation soon. 

  • Electricity storage Available capacities in the field of electricity storage (pumped storage power plants, power-to-gas (hydrogen or methane) and battery storage) are key to the electricity management of the future. The more capacity available in this field, the better the renewable energy sources can be used and the electricity managed reliably. 

99,99 %

Security of supply Austria is in Europe’s top league with security of supply of 99.99%


Capital expenditure Capital expenditure by APG for the reliable transformation of the energy system: €3.5bn by 2032, €357m in 2021


Cost of a blackout Daily cost of a blackout for Austria’s economy: €1.2bn

12-48 h

Time needed to fix the blackout Time needed to gradually fix the blackout: 12–48 hours


Regular training Regular training of APG staff in Duisburg, Germany, for the TSO operations management simulator

Crisis drills

Regular crisis drills Regular crisis drills at a national and international level with ministries, authorities, other distribution system operators and the emergency services


Intervention in the working timetable 2021 Number of interventions in the working timetable: nearly every other day

Past frequency disturbance

The last major frequency disturbance causing widespread power failures in Europe occurred on 4 November 2006 when a major frequency disturbance led to outages across Europe at 10:09 p.m. Parts of Germany, France, Belgium, Italy, Austria and Spain were without electricity for up to 120 minutes. This was triggered by the scheduled temporary disconnection of a 380-kV high-voltage line operated by E.ON near Weener on the evening of 4 November 2006 for the disembarkation of the Norwegian Pearl, a cruise ship built at the Meyer Wharf in Papenburg, Germany. 


Most recent incident- Simulation

The most recent precarious incident in Europe occurred on 8 January 2021. Details can be seen in the video simulation.

Every day, the team of specialists from APG and the other electricity grid operators in Austria and Europe ensure a secure supply of electricity for everyone living in Austria and a reliable transformation towards a sustainable energy supply. .

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