Power outage in July in Valais cleared up


As in many European countries, the Swiss transmission grid already today – at the beginning of the energy transition – has structural bottlenecks. Here, as elsewhere, these must be eliminated to increase security of supply and maintain it in the long term. Tense grid situations may pose problems to the connected system, as the Swiss transmission system operator (TSO) Swissgrid experienced on 17 July 2020, when the protection equipment of the 220kV grid node Creux de Chippis was accidentally tripped, which in the further course of events led to supply interruptions in the Valais distribution grid. The TSCNET shareholder immediately initiated extensive investigations into the event, the results of which have now been transparently communicated.

An extremely complex chain of technical and human factors is behind the Chippis incident. First the technical aspects: The transmission grid capacities in the region around Chippis are insufficient in summer due to the high generation of Alpine hydroelectric power plants. Because of this, Swissgrid for some time now had to completely disconnect the transmission grid in the Mörel substation in east-west direction for around 15 weeks a year to guarantee grid security and transmission capacities in the region. This reduces fault tolerance in the regional transmission system. In addition, several extension projects are currently being implemented in the Chippis area, which made adjustments to the operation of the Chippis substation necessary. These settings – also affecting the protection settings of the system – were carried out by the contracted service provider in December 2019.

As regards the human factor in the chain of events, necessary and scheduled tests of protection parameters were performed by a contracted specialised company in the Chippis substation on 17 July. During these tests, the system was not put into revision mode, which is why the system protection function unintentionally detected the test signal. This triggered the so-called busbar protection. The switchgear in the Chippis substation was subsequently disconnected and, due to the special grid situation, the switchgears in Stalden, Bitsch, Zermeiggern, and Mörel were also affected by the voltage loss, leading to a regional supply interruption in the distribution system.

The result of this combination of occurrences was a power failure in 60 municipalities in the district of Sierre and in most of the Upper Valais. After one hour, all affected switchgear and Swissgrid lines were back in regular operation. Thanks to the good cooperation between Swissgrid and the concerned distribution system operators (DSOs) of the lower voltage levels, electricity supply was gradually resumed and after less than two hours, almost all customers were back on power. Adrian Häsler, Head of Grid Infrastructure at Swissgrid, classifies she supply disruption in Valais as “an extremely rare occurrence”, but nevertheless apologises to those affected. And though the tests themselves were not negligent, the findings from the incident are incorporated into the company’s training and education of internal and external experts. Häsler also emphasises that Swissgrid drew attention to the bottlenecks in Valais some time ago: “Incidentally, we recognised these grid congestion problems in the context of ‘Strategic Grid 2025’, the TSO’s ambitious grid modernisation and extension plan, and addressed them in 2015. The grid expansion as planned by Swissgrid is essential to maintain the long-term security of supply.”

Swissgrid is investigating the voltage loss in the switchgear of the Chippis substation in Valais on 17 July (picture: Swissgrid)

> See Swissgrid media release (html)
> See Swissgrid blog post (html)

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Grid and supply security in times of COVID-19


Transmission system operators (TSOs) are managing an integral part of our society’s systemically relevant critical infrastructure, which must be maintained under all circumstances. In the current global health crisis, the TSCNET shareholders, like all other TSOs, are aware of their specific responsibility for the security of European electricity supply, which is a matter of preserving social and economic life. The TSOs are focusing on their core business: secure electricity supply, and have taken technical precautions, especially in sensitive areas such as the control centres. But of course, hygienic and social measures are also adopted with regard to the safety of their customers, business partners and employees.

As far as the TSO’s own employees are concerned, as many colleagues as possible are sent to work from home. For a large number of technical staff, e.g. in the areas of monitoring, maintenance or repair, this is obviously only possible to a limited extent. The four German TSOs for example have taken a number of precautionary measures. These include in particular:

  • Strict rules regarding business trips and contact with other persons.
  • Special requirements apply to the staff in the control rooms and in the technical teams which are absolutely necessary for the maintenance of the grid. Generally speaking, the control rooms are equipped for all emergencies, far beyond the current threat from the corona virus.
  • The precautionary measures taken are checked daily and adjusted to the current situation if necessary.
  • The individual TSOs also adapt their measures in accordance with the rules and regulations applicable in their respective grid areas.

To play an active role in the containment of COVID-19, the TSOs also respond with such understandable measures as access restrictions or the cancellations of meetings and public information events. Instead, the companies are opting for online conferences. 50Hertz, for example, one of the four German TSOs, is introducing an online participation system as a replacement for the cancelled information events for example on the transregional SuedOstLink power line so that citizens can be continuously involved in the planning process.

The European TSOs contribute actively and responsibly to the containment of SARS-CoV-2 without compromising system security (electron microscope image of SARS-CoV-2: NIAID, CC BY 2.0)

> 50Hertz, in German (html)
> APG, in German (html)
> Energinet, (html)
> TenneT Germany press release, in German (html, published on 17 March)
> TransnetBW, in German (html)

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New Nordic System Operation Agreement


The five Nordic power transmission system operator (TSOs), including the Danish TSCNET shareholder Energinet, have signed a new Nordic System Operation Agreement. This agreement sets out the common operating principles of the Nordic TSOs to ensure that the Nordic interconnected system is operated reliably and efficiently in accordance with national and European regulations.

Against the background of the increasing volatility of electricity generation due to renewable energies and the reduction of balancing power generation, the Operating Agreement will further strengthen Nordic cooperation, harmonise grid operating practices between Nordic countries and within Europe, and ensure the system security of the Nordic electricity system.

The document will also contain several appendices, of which the appendix on reserves has already been concluded. The Nordic TSOs are in the process of finalising further appendices on all relevant operational issues. The new Operation Agreement will successively replace the existing one after the completion of the new appendices.

Energinet and the other four Nordic TSOs have signed a new Nordic System Operation Agreement (picture showing Copenhagen, Denmark)

> See Energinet press release (html)
> Open Nordic System Operation Agreement (pdf, 894.16kB)

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50Hertz to improve grid utilisation


To respond to current and future transmission system requirements, operators can either expand the grid or optimise its utilisation – ideally, they do both. TSCNET shareholder 50Hertz, one of the four German transmission system operators (TSOs), is also facing up to the challenges arising from the higher capacity load on the existing grid. The TSO presented its innovative assets and concepts at the System Security Conference (“Systemsicherheitskonferenz”), which is held every two years by 50Hertz.

This year’s conference on 28 August, the 11th edition, attracted almost 150 participants from the energy industry, science, politics and administration to the Berlin headquarters of 50Hertz, where they were welcomed by 50Hertz CEO Dr. Frank Golletz, who also plays the role of the company’s CTO. Golletz explained how the TSO tackles the technical challenges using previously uncommon technologies such as static compensators (STATCOM), series compensations, back-to-back converters or static and rotary phase shifters. “With these assets, our grid becomes a highly dynamic grid in which the power flow is actively controlled,” commented Golletz.

In addition, Golletz argued that, alongside to the indispensable technical innovations, the rules on the energy market should also be continuously further developed. It is important to set the right incentives for all market participants so that the electricity market not only functions from a business point of view, but also keeps an eye on the entire economy.

50Hertz has held its 11th System Security Conference in Berlin, Germany (picture of headquarters: 50Hertz)

> See 50Hertz press release (html)

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TransnetBW order for “bnBm” gas power plant


TSCNET Services shareholder TransnetBW, one of the four German transmission system operators (TSOs), has awarded Energie Baden-Württemberg AG (EnBW) the contract for the provision of a “special network equipment” (“besonderes netztechnisches Betriebsmittel”, bnBm). EnBW will construct and operate a gas turbine power plant with a capacity of 300MW at Marbach. The city is the birthplace of the poet Friedrich Schiller and is located about 20 kilometres north of Stuttgart on the Neckar River.

The special network equipment will not be available to the market, but will be used from 1 October 2022 as a “safety buffer” exclusively at the request of TransnetBW to ensure safety and reliability in the transmission grid. It thus serves as a further reserve for the safety and reliability of the electricity supply system.

“Behind us lies a demanding tendering procedure, because we had to procure a completely new product,” says Dr. Rainer Pflaum, Managing Director of TransnetBW. It was about access to a capacity that “helps to stabilise the power grid flexibly and reliably”. The new plant would be an important component for supply security in the region.

Together with the TSOs Amprion and TenneT, TransnetBW issued a call for tenders for the special grid technology equipment with a total volume of 1,200MW open to technology and Europe-wide at the end of June 2018. Altogether, the tenders cover four regions in southern Germany, each with a capacity of 300MW.

TransnetBW placed an order for the provision of a gas turbine power plant with a capacity of 300MW (picture: EnBW)

> Open TransnetBW press release, in German (html)

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Publications on HDVC reliability and the balancing market


The European Network of Transmission System Operators for Electricity (ENTSO-E) has adopted positions on two systemically relevant topics for the European energy market: the electricity balancing market and the improvement of high-voltage direct current (HVDC) system reliability. Two respective papers have been released by ENTSO-E. The first, a balancing guideline, gives a simplified overview of the target model of the European balancing energy market and explains the most important concepts and processes associated with this market and the platforms for the exchange of balancing energy products. In addition to the focus on the interaction of the different balancing processes, the legal framework of the target model is also briefly outlined.

In its position paper on HDVC reliability, ENTSO-E recognises HDVC as an increasingly important method of transmitting large quantities of electrical energy for the Europe-wide transmission grid. As new HVDC connections play a key role in the future development of the continental transmission system, the reliability, availability, compatibility and robustness of the technology will be crucial for market and system security. For future challenges, high system security and the needs of an efficient European integrated market, it is essential that the owners of HVDC installations, together with other relevant HVDC stakeholders, focus not only on technology innovation but also on further process development, HVDC network integration studies and the maintainability to be carried out by transmission system operators (TSOs). ENTSO-E strongly supports more efficient cooperation between all HDVC players.

ENTSO-E has released a European electricity balancing guideline as well as a position paper on improving the reliability of HVDC systems  (picture of HVDC Plus IGBT converter modules: Siemens AG, www.siemens.com/presse)

> See ENTSO-E press release on balancing market (html)
> Open Balancing Guideline (pdf, 892.3kB)
> See ENTSO-E press release on HDVC reliability (html)
> Open HDVC paper (pdf, 1.8MB)

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Nordic TSOs to open RSC in February


The Nordic transmission system operators Fingrid from Finland, Statnett from Norway, Svenska Kraftnät and the Danish TSO and TSC member Energinet.dk agreed on their meeting of 16 November 2016 on a common Regional Security Coordinator (RSC) office similar to TSCNET Services based on the system operation guideline approved by the EU member states. The four TSOs wish to intensify their cooperation in terms of regional system operation, system security and the implementation of the new Nordic market for automatic frequency restoration reserve (aFRR).

The Nordic RSC office is to be officially opened in Copenhagen, Denmark, on 1 February 2017. As a service tool of the TSOs it will provide, inter alia, transmission capacity calculations, security analyses and adequacy forecasts. The common aFFR-market will be beneficial concerning the maintaining of good frequency quality and the integration of an increasing amount of renewables into the Nordic power system.

Furthermore, the TSOs announced a “Solution report” as sequel to their “Challenges of the Nordic Power System” report. The new paper will cover aspects of transmission adequacy, generation adequacy, flexibility and inertia and is to be published in June 2017.

> See Energinet.dk press release (html)

Picture showing Copenhagen by night (Copenhagen Media Center)


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System security conference in Erfurt


On the 5th and the 6th of September, TSC member 50Hertz, one of the four German transmission system operators (TSOs), held its annual system security conference (“Systemsicherheitskonferenz”) in Erfurt, the capital and biggest city of Thuringia, Germany. The theme for this year’s conference was digitalisation as a key to a successful energy transition. More than 165 experts from TSOs and DSOs, energy producers, industry, politics, NGOs and science used the conference as a forum for discussion.

> See 50Hertz press release, in German (html)

Picture: 50Hertz


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