Power outage in July in Valais cleared up

09.09.2020

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)

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

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TenneT commisions “green” substation

04.09.2020

In recent years, the seaport of Eemshaven in the province of Groningen in the north of the Netherlands has become more and more important for the Dutch energy transition. Eemshaven has taken on the role of an energy port: with power plants, sustainable generation, connections to offshore wind farms, and submarine cable interconnectors to Norway and Denmark. The Dutch-German transmission system operator (TSO) TenneT – together with regional distribution system operator (DSO) Enexis Netbeheer – now has commissioned the new high-voltage substation Eemshaven as the first substation entirely built for the suply of wind and solar energy.

The station was built as part of the grid reinforcement for the growing amount of sustainably generated energy in the north of the Netherlands which requires an increase in transmission capacity. Other measures of the TSCNET shareholder include a 380kV connection between the Eemshaven (Oudeschip) high-voltage substation and Vierverlaten near Groningen as well as the extension of the Vierverlaten substation. This new 380kV “power highway” will replace the existing 220kV line. Until it is put into operation – scheduled for 2023 – TenneT will commission a provisional 380kV substation in Eemshaven (Oostpolder) in October 2020.

TenneT has put into operation the new substation Eemshaven for the supply of green electricity (picture: TenneT)

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> See TenneT press release, in Dutch (html)

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Building permit for the Uckermark line of 50Hertz

13.08.2020

Since 2005, 50Hertz, the transmission system operator (TSO) from the north-east of Germany, has been engaged in the planning of the new, higher capacity Uckermark Line (“Uckermarkleitung”). The new 380kv overhead line is to replace the existing 220kv line that went into operation in 1958, whereby the TSCNET shareholder takes account of the growing relevance of renewable energies in its control area. The new Uckermark Line will run from the Bertikow substation near Prenzlau to the Neuenhagen substation in the north-east of Berlin and connect further substations, one of which is an important interconnector to Poland. It will be capable of transmitting up to five times more electricity, so that in future more wind and solar power from the German states of Brandenburg and Mecklenburg-Western Pomerania can be transported to the southern consumption centres.

The start of construction of the 115-kilometre-long new line was delayed for reasons of bird protection: A German nature conservation association had filed a complaint against the planning approval decision granted in 2014. This necessitated a supplementary planning procedure, expert reports on bird protection, consultations, and modifications. The competent authority now granted the building permit, which maintains 50Hertz’ originally planned routing. The future Uckermark Line will no more affect the biosphere reserve Schorfheide-Chorin and thus pays considerable attention to nature conservation. Special permits have been issued for other bird sanctuaries that cannot be bypassed due to their size, including compensation measures to preserve biodiversity. The dismantling of the old power line plays an important role here, but also bird protection markers or special pylons with reduced height.

50Hertz has been cooperating for several years with various nature conservation organisations and ornithological observatories to better assess the possible threats to birds. A nationwide cooperative portal of TSOs and distribution system operators (DSOs) in conjunction with the Renewables Grid Initiative (RGI) for data on detected accident birds is particularly noteworthy in this context. To increase acceptance of a project as essential for the energy transition and climate protection as the Uckermark Line, it is important to reconcile the substantial ecological added value of the capacity expansion with other nature conservation interests. Hence, the commitment of 50Hertz both to the ecologically necessary grid extension and to other environmental interests is highly to be appreciated.

50Hertz has obtained construction permit for the new 380kV Uckermark line (symbolic picture: 50Hertz) 

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> See 50Hertz press release (html)

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Swissgrid analyses supply disruption in Valais

22.07.2020

On Friday, 17 July, the Swiss transmission system operator (TSO) Swissgrid carried out check-operations concerning the extension of the 220kV switchgear in the Chippis substation in the canton of Valais. At 4.23 p.m., the protection equipment of the 220kV grid node Creux de Chippis was accidentally tripped, causing the switchgear to lose voltage. As a result of the technical failure at Chippis, the switchgear of the substations in Stalden, Bitsch, and Mörel were also affected by the voltage drop, which led to a regional supply interruption in the distribution system.

The result was a one-hour power outage in a total of 60 municipalities with around 112,000 households as well as trade and industry in the Swiss Sierre district and the largest part of the Upper Valais. By 5.23 p.m., all affected switchgear and lines of the TSCNET shareholder were back in regular operation. Thanks to the good cooperation between Swissgrid and the five affected distribution system operators (DSOs) of the lower voltage levels, it was possible to gradually restore the electricity supply from 5 pm onwards. By 6.15p.m. almost all customers were back on power. Swissgrid immediately initiated a detailed investigation of the incident, which is currently in progress.

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

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> See Swissgrid news release, in German (html)

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SVC for SINCRO.GRID in Konjsko

02.07.2020

As in many parts of Europe, the increasing integration of decentralised, volatile renewable energy sources has also led in Croatia and Slovenia to a lack of flexibility and reactive power. The two TSCNET shareholders HOPS, the transmission system operator (TSO) from Croatia, and ELES, the Slovenian TSO, react to this with their joint project SINCRO.GRID that also involves two distribution system operators (DSOs) from the respective countries. The European Project of Common Interest (PCI) aims to optimise the efficiency of the two national electricity transmission networks through advanced technologies and innovative data processing methods. These include compensation devices, a dynamic thermal rating system, a battery power storage system, and a virtual cross-border control centre.

The start of construction of a static VAR compensator (SVC) in the Dalmatian substation in Konjsko on 30 June represents another significant milestone in the implementation of SINCRO.GRID. This state-of-the-art compensation system will support HOPS in actively controlling the reactive power flows in the Croatian power grid. The ceremony to mark the construction start was attended by high-ranking representatives of the Croatian government and the energy companies involved.

In addition to the SVC in Konjsko, SINCRO.GRID comprises three further main elements in Croatia: a variable shunt reactor (VSR) in the Mraclin substation near Zagreb, which was commissioned in January 2020, another VSR in the Melina substation, which is scheduled to be commissioned at the end of 2020, and finally a joint Croatian-Slovenian virtual control centre. Tomislav Plavšić, President of the HOPS Management Board, describes the latter as a unique solution for coordinated voltage regulation on the entire territory of both countries. The principal task of the binational virtual centre is to integrate three devices each in Croatia and Slovenia for reactive power compensation into one common operation to fully exploit their synergy potential.

HOPS has commenced construction of a SVC as part of the SINCRO.GRID project in Konjsko (picture with Tomislav Plavšić in the foreground: HOPS)

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> See HOPS press release, in Croatian (html)
> Visit SINCRO.GRID website (html)

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DA/RE project: Redispatch 2.0

09.04.2020

The grid security initiative DA/RE (“DAta exchange/Redispatch”) was launched in summer 2018 by TransnetBW, the transmission system operator (TSO) from the south-western German state of Baden-Württemberg, and entered the pilot phase on 1 April 2019. The first retrievals of redispatch capacities were carried out in summer 2019 and now the pilot phase of the Baden-Württemberg grid project has been successfully concluded. Apart from TSCNET shareholder TransnetBW, three distribution system operators (DSOs) and four other partners from the fields of virtual power plants, home storage, and energy trading were involved in the DA/RE pilot phase.

Like comparable projects, DA/RE responds to the increasing volatility and decentralisation of electricity generation. In order to stabilise the entire electricity system in the future, DA/RE intends to facilitate the transition from the current redispatch with centralised large-scale power plants to new processes involving the flexibility potential of smaller decentralised generation plants and storage facilities. In the pilot phase, the DA/RE partners have achieved their first project goal: Processes for the coordinated retrieval of redispatch power from the distribution grid over several voltage levels have been developed and successfully tested in practice. The entire process chain from the exchange of planning data via DA/RE internal processes with merit-order based plant selection up to the activation of the physical plant retrieval was tested in three steps. A total of 40 plants of different technologies with rated outputs between 3kW and 30MW were involved.

Key assumptions corroborated
In the pilot phase, the coordinated redispatch retrieval was verified across all voltage levels and the basic functionality of the DA/RE concept was confirmed. With the experience and findings gained from this, the final DA/RE platform is now being developed, for which uniform processes and interfaces to automate the process steps will be defined. This will ensure the scalability and mass suitability of the system and simplify the integration of smaller grid and plant operators.

The two DA/RE project managers, Florian Gutekunst from TransnetBW and Kilian Geschermann from the DSO Netze BW, describe DA/RE as an open project: “We are looking forward to involving further interested parties from the ranks of grid and plant operators as fellow campaigners. We are all facing growing challenges due to the transformation of the generation landscape; together we can find smart solutions and better meet the challenges.”

The pilot phase of the DA/RE project for smart decentralised redispatch solutions has successfully been concluded

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> See TransnetBW press release, in German (html)
> Visit DA/RE website, in German (html)

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Smart Grid of the future tested

07.04.2020

Small decentralised power generation plants, storage units and consumers must increasingly take on the role of stabilising the transmission system, a task that has so far been performed mainly by large, centralised power plants. The Dutch-German transmission system operator (TSO), TSCNET shareholder TenneT, is participating in two projects investigating the technical feasibility of decentralised stabilisation options. These two projects are C/sells with a focus on southern Germany and solar energy and enera with a focus on northern Germany and wind energy. Besides TenneT, C/sells and enera comprise various actors from the energy sector, research institutions and distribution system operators (DSOs). Both projects involve regional online platforms for the management of decentralised flexibilities and are funded by the German Federal Ministry for Economic Affairs and Energy in the framework of the innovation programme “Smart Energy Showcases” (“Schaufenster intelligente Energie” – SINTEG).

To connect suppliers and demanders of flexibility, C/sells has developed a flexibility platform called “comax”: Providers of flexibility report existing potential and grid operators can access this potential and coordinate with each other to retrieve their respective needs. In the enera project, a stock exchange-based local flexibility market is being developed that merges supply and demand for flexibility and allocates it to grid operators in a highly efficient manner. By linking the two online platforms of C/sells and enera, the smart grid of the future has now been field-tested and the targeted control of decentralised electricity consumers, storage facilities and generators has been trialled under real conditions throughout Germany for the first time.

During the test run, in coordination with the DSOs involved, the electricity demand of a storage facility in the northern windy state of Lower Saxony was increased at the request of TenneT to absorb electricity from renewable energy sources. At the same time, biogas and CHP (combined heat and power) plants in the south of Germany fed more electricity into the grid to meet the local demand. This has reduced the amount of electricity to be transmitted through the power grid and helped to eliminate bottlenecks.

Tim Meyerjürgens, COO at TenneT, comments on the successful test: “In the future, we will need millions of decentralised systems to stabilise the transmission grid. To this end, grid operators at all levels must collaborate and develop new tools to exploit the potential of CHP plants, heat pumps, biogas plants, battery storage, electric cars, power-to-gas plants and other decentralised facilities for greater grid security. Our test has shown how this works successfully.”

TenneT carried out a successful test on how to use decentralised consumers, storage facilities and generators to stabilise the grid (picture: screenshot taken from the C/sells website)

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> See TenneT press release, in German (html)
> Visit C/sells website (html)
>Visit enera website, in German (html)

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DA/RE project: first retrievals of redispatch capacities

11.07.2019

The Baden-Württemberg grid security initiative “DA/RE” (“DAta exchange/REdispatch”) addresses the increasing volatility and decentralisation of power generation. The aim is to stabilise the entire electricity system by utilising the flexibility potential of decentralised generation units from lower grid levels. Originally launched in the summer of 2018 by TSCNET shareholder TransnetBW, the German transmission system operator (TSO) from the state of Baden-Württemberg, and the southwest German distribution system operator (DSO) Netze BW, the project consortium was later expanded so that a total of three DSOs and four other partners from the areas of virtual power plants, home storage and energy trading were involved in the first DA/RE pilot phase from April to June 2019.

During this phase, the participants have defined and developed the method of data exchange and coordination. Following this successful implementation process, the first retrievals from pilot plants in the distribution network for redispatch purposes have now been initiated. Capacities were retrieved from battery home storage facilities, several biogas plants, a waste incineration plant and a cogeneration plant. The tests therefore involved both medium-voltage and low-voltage systems and the project partners have demonstrated that it is possible and important to make use of all flexibilities at all voltage levels for grid stabilisation.

“The retrievals from systems in the distribution network constitute a significant milestone for us, as they show that the concept is feasible and we are now able to gain initial experience in terms of practical suitability,” explains DA/RE project manager Florian Gutekunst from TransnetBW. The second stage of the pilot phase has thus begun. Further retrievals are now being carried out and various application cases are being tested. In concrete terms, the issue is how grid operators can trigger the retrieval of redispatch measures in a coordinated manner and how the information chain should be designed in order to guarantee all parties involved at all voltage levels complete transparency about the retrieval and the capacity provided. In the following third step, the retrievals are to be automated and the corresponding data paths implemented.

First retrievals of redispatch capacities have been carried out in the pilot phase of the DA/RE project (picture showing a scene from electricity trading: Next Kraftwerke)

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> See TransnetBW press release, in German (html)

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Connect+ for data exchange

14.06.2019

The four German transmission system operators (TSOs), the TSCNET shareholders 50Hertz, Amprion, TenneT, and TransnetBW, together with 16 distribution system operators (DSOs) have launched the “Connect+” project to jointly implement the legal requirements of the German Grid Expansion Acceleration Act (Netzausbaubeschleunigungsgesetz – NABEG). The project is a reaction to the increased need for coordination due to the current legislative amendments and intended to facilitate a more transparent exchange of data between grid operators and market participants.

German legislation has specified that, in future, all facilities for the generation or storage of electrical energy with a nominal capacity of 100kW or more must be utilised to prevent foreseeable bottlenecks in the grid. The modified conditions for redispatch apply from 1 October 2021. As the present feed-in management of the grid operators only reacts to acute congestions, an even more intensive cooperation between TSOs and DSOs is required in the future.

The new processes to be developed and introduced within the time frame pose a challenge for all grid operators. In the “Connect+” project, TSOs and DSOs want to develop uniform solutions for data distribution to harmonise data exchange between market participants and operators for congestion management. In a first step, essential specifications such as interfaces and formats are developed and defined.

The four German TSOs and 16 DSOs launch the data exchange project “Connect+” for congestion management

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> See Amprion press release, in German (html)
> See TenneT press release, in German (html)
> See TransnetBW press release, in German (html)

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AI for decentralised grid stabilisation

06.06.2019

In a sustainable energy future, small decentralised plants such as combined heat and power (CHP) plants, heat pumps or biogas units must assume the role of stabilising the transmission system, a task which is nowadays mainly performed by large, centralised power plants. To investigate the technical feasibility of decentralised stabilisation options, TSCNET shareholder TenneT, the Dutch-German transmission system operator (TSO), the distribution system operator (DSO) Bayernwerk and Consolinno Energy GmbH have now jointly carried out a successful test in the southern part of the TenneT control area, the German federal state of Bavaria.

Since there is a vital public interest in such future-oriented technological solutions, the test was funded by the German Federal Ministry for Economic Affairs and Energy in the framework of the research project “C/Sells” which is part of the innovation programme “Smart Energy Showcases. Digital Agenda for the Energy Transition” (“Schaufenster intelligente Energie. Digitale Agenda für die Energiewende” – SINTEG). During the test, at the request of TenneT, the feed-in of a CHP plant controlled by Consolinno and connected to the low and medium-voltage grid of Bayernwerk was increased in order to provide the grid with the electricity required for stabilisation in the event of a bottleneck.

What is new is that each plant autonomously determines its flexibility potential through artificial intelligence (AI). The respective potential of the individual plants can then be further aggregated by means of swarm intelligence. The plants are in normal marketing and operation mode and report free flexibility quantities to the grid operators. “In Bavaria alone there are several thousand CHP plants, heat pumps and biogas facilities, nationwide there are many thousands more. They can increase the flexibility of the energy system and thus contribute to a safe and decentralised energy system in Bavaria and Germany. David can thus become Goliath,” comments Tim Meyerjürgens, COO at TenneT. Also in several other cooperative pilot projects, the TSO is exploring the potential of decentralised flexibility.

TenneT has carried out a successful test on the deployment of small decentralised plants for grid stabilisation

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> See TenneT press release, in German (html)

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