German field report on underground cabling

07.10.2020

The use of underground cables for power transmission in the extra-high voltage three-phase current range is partly still uncharted technical territory for the four German TSCNET shareholders 50Hertz, Amprion, TenneT, and TransnetBW. As most projects are in the planning, approval, or construction phase, no partial earth cabling project is yet in full system operation, let alone a project with exclusive cabling. However, Tennet has commissioned the Wilhelmshaven-Conneforde line as recently as last week: It is the first 380kV line with underground cable sections in three-phase technology connected to the meshed power grid by the Dutch-German transmission system operator (TSO).

To inform politics and public about the current status of underground cabling in the national transmission system, the four German TSOs have, at the request of the German Federal Ministry for Economic Affairs and Energy, jointly prepared a field report on the use of underground cables in the extra high-voltage three-phase current range. The 65-page report examines seven different key issues in respective main chapters, covering technical, administrative, economic, environmental, and social aspects: dialogue and acceptance, approval procedures and the environment, design and construction, operation and operational safety, underground cable technology, systems engineering, and finally economic efficiency. Key findings of 50Hertz, Amprion, TenneT, and TransnetBW can be summarised as follows:

  • Partial underground cabling does not per se lead to a greater acceptance of line construction projects – compared to the construction of overhead power lines, the concern merely shifts from the residents mainly to landowners and farmers.
  • As far as planning, approval, and construction times are concerned, current experience shows that partial underground cabling requires at least one to two years more than overhead lines. More extensive implementation planning, intensive soil investigations, and negotiations with the owners consumed a great deal of time in the pilot projects. The construction itself is also more complex due to the necessary crossing of infrastructures, 40 to 60-metre-wide aisles, and major interventions in the soil ecosystem.
  • Regarding operational and system safety, underground cable installations have a lower availability rate than overhead lines, as repair times are significantly longer in case of damage. Moreover, with an increasing share of partial underground cabling, the complexity of grid operation and thus the risk to system stability also rises.
  • In terms of economic efficiency, the costs of partial underground cabling are significantly higher than those of overhead lines, and this applies to planning, construction, and operation. Depending on the project-related terrain and soil conditions, the investment costs are usually six times higher.

The four German TSOs have published their joint “Field report on the use of underground cables in the extra-high voltage three-phase current range” (picture: TenneT)

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> See TransnetBW news release, in German (html)
> Open Field Report, in German (pdf, 2.9MB)

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Nordic Power Solutions Report

29.04.2020

The Nordic transmission system operator (TSOs) of Finland, Norway, Sweden, and the Danish TSCNET customer Energinet have updated their 2018 report “Solutions for a changing Nordic power system”. The Solutions Report 2020 provides an overview of the joint Nordic TSO projects that have been identified as crucial to address the challenges in the Nordic energy system.

As in the rest of Europe, the Nordic power system is undergoing the most significant changes since the liberalisation of the electricity markets, and here, too, these changes are mainly based on a new power generation mix with volatile generation and distributed resources. The Power Solutions Report 2020 draws a common picture of the progress of the new solutions in the Nordic power system that respond to these changes. In addition to reporting on the projects, the report also features comments from stakeholders on the tasks and the challenges they still see in the Nordic power grid.

Energinet and the other Nordic TSOs have published their joint Nordic Power Solutions Report 2020 (picture: Bo Kamstrup, Pixabay)

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> See Energinet press release (html)
> Open Nordic Power Solutions Report (pdf, 10.62MB)

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TenneT on track for the energy transition

31.07.2019

Highly satisfactory business results and maintenance of the high level of 99.99% security of supply, are hallmarks of the half year report of the Dutch-German TSCNET shareholder Tennet. The latter is a growing challenge for the transmission system operator (TSO) because of the increased feed-in of volatile renewable energy. But above all, the report illustrates the commitment of the TSO to the European energy transition.

To take further steps in shaping the energy system of the future, TenneT has launched a series of strategic initiatives and partnerships to join forces across sectors. TenneT is participating in a German power-to-gas pilot project and is working together with regional grid operators and market partners on smart solutions to optimise the use of existing electricity infrastructure. The TSO is also involved in blockchain pilots to create flexibility for balancing the power system from decentralised sources.

TenneT has further strengthened its position as a leading offshore TSO. In Germany, TenneT has awarded DolWin 5, the 14th offshore grid connection. TenneT will increase its current offshore transmission capacity from 6,232MW in the German North Sea to almost 9GW by 2024. In the Netherlands, too, the development of the offshore grid with the Borssele Alpha and Beta projects is on schedule. TenneT intends to provide a total of 10.6GW of connection capacity for Dutch offshore wind farms by 2030. The TSO is also carrying out several onshore projects to ensure the transport of the growing amount of green electricity and thus security of supply in its control areas. Important interconnecting projects are the NordLink cable connection, which is currently being built to directly link the German and Norwegian markets for the first time. The COBRAcable between the Netherlands and Denmark has “landed” at the Dutch shore and will go into operation this year.

These developments are complemented by solid and impressive figures: Underlying operating result (EBIT) rose from €362m (first half of 2018) to €407m in the first half of 2019. €1,094m (first half of 2018: €904m) were invested in the Dutch and German high-voltage grids (of which €612m in Germany) and a total of €1.75bn green bonds were successfully issued. Manon van Beek, CEO of TenneT, comments on the report: “We have embarked on an irreversible transition to a sustainable society and a new energy system. This requires investments, not only in new electricity connections, but also in innovations and digitalisation. We have to move to holistic energy system thinking and also work on solutions to make better use of the existing high-voltage grids. We are convinced that this is the way forward to limit social costs and at the same time maintain a very high security of supply.”

TenneT presents its half year report 2019 (picture: TenneT)

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> See TenneT press release (html)
> Open Half year report 2019 (pdf, 803kb)

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Investing in energy transition – TenneT report

25.07.2018

The Half Year Report of the Dutch-German TSCNET shareholder TenneT does not only provide satisfactory figures, but also shows that the business of a transmission system operator (TSO) with a control area from the seashores to the Alps is essentially divided into two parts: connecting offshore wind energy capacity to the onshore grid and ensuring the transport of sustainable generated electricity to wherever it is needed. To further support the energy transition, TenneT is accelerating the realisation of large-scale projects in the Dutch sector of the North Sea and on the German mainland. The TSO’s commitment to the European energy future is reflected with a total of €904m of investments in the transmission systems in the first half of 2018 ‒ not only impressive compared to the first half of 2017 (€750m).

By 2030, TenneT plans to have connected a total of 11.5GW of offshore wind energy to the grid in the Netherlands. Three years earlier, in 2027, the TSO aims to achieve a total transmission capacity of 11GW for the German North Sea. The most outstanding onshore infrastructural projects are the German supraregional extra-high voltage lines SuedLink and SuedOstLink with a length of 700km and 580km, respectively, and a combined capacity of 6GW. Both DC lines will partially be realised by means of underground cabling and are joint ventures of TSCNET shareholders. On SuedLink, TenneT cooperates with TransnetBW, and on SuedOstLink with 50Hertz. To help financing its investments in the transmission of the renewables, TenneT in March 2018 again has issued long term green bonds in two tranches with a nominal total value of €1.25bn. Altogether, TenneT has issued €6.25bn in green bonds to date.

Mel Kroon, CEO at TenneT, emphasises the company’s “central position in the energy transition” and considers that the construction of new infrastructure alone is not enough to meet the challenges of the future, “but also the development of innovative hard- and software systems for real-time coordination of the variable supply of green electricity.” Mr Kroon expresses the need for a new energy system, and points out the unexploited potential of green hydrogen for flexibility and storage solutions: “Following the successful development of offshore wind energy, we now need to focus on promoting the production of green hydrogen in order to facilitate long-term energy storage and make the industrial and transport sectors far more sustainable.”

TenneT, the Dutch-German TSO, presents the Half Year Report 2018

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> See TenneT press release (html)
> Open Half year report 2018 (pdf, 803kb)

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Danish security of supply among the best

09.07.2018

An availability rate of electricity of 99.995% of the time in 2017 is quite impressive, and the Danish TSCNET shareholder Energinet is the transmission system operator (TSO) presenting this outstanding value in its “Security of electricity supply report 2018”. With this remarkable confirmation of last year’s result (99.996%), Denmark is again among the leading European countries. According to Energinet, the excellent security value is partly due to the high level of underground cabling in Denmark.

The key features of today’s energy landscape ‒ such as the integration of extensive and increasing wind and solar power capacities, more electricity interconnectors between different countries, or the harmonisation of markets and grid operation via EC regulations ‒ all affect the Danish supply security, which is no longer a national, but a regional issue. Energinet is aware of the new challenges and will adress these with operational and infrastructural measures, but also with the introduction of market reforms to increase the flexibility of both, generation and consumption.

TSCNET shareholder Energinet, the Danish TSO, presents impressive figures in its Security of electricity supply report 2018.

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> See Energinet press release, with access to report (html)

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Modernisation and stable operation in Czechia

17.09.2017

A significant and future-oriented project, which TSC member ČEPS, the Czech transmission system operator (TSO), has long been advancing with great vigour, is finally complete: All four phase-shifting transformers (PSTs) with phase angle regulation at the Bohemian substation in Hradec u Kadaně are now in full operation and regulate the electricity flows of two 400kV interconnectors between the Czech Republic and the eastern part of Germany. Not only do the PSTs contribute to grid stability in Czechia and beyond, but they also help to prevent expensive remedial measures.

This is the prominent feature of the ČEPS report on the second quarter of 2017, which also provides otherwise with good news, such as a profit before tax of CZK 1.5bn (about €57.5m). That is an increase of nearly CZK 275m (about €10.5m) compared to last year’s corresponding period. The ambitiuos grid investment programme of the Czech TSO can nothing but benefit from this gratifying development. The reconstruction of a gas-insulated section of the Chodov substation in Prague, the country’s capital and largest city, or the construction of a new transformer station in Vernéřov in the region of Ústí nad Labem are only two of several projects in order to maintain system security and increase transmission capacities.

> See ČEPS press release (html)

Picture: ČEPS

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Collaboration and innovation – TenneT report

28.07.2017

A whole lot of aspects from the half-year report of TSC member Tennet are worth mentioning, but what might be considered as especially valuable and forward-thinking is the continuing effort of the Dutch-German transmission system operator (TSO) in promoting the European energy collaboration and market integration. Tennet complements these efforts with the development of digital solutions for the renewable’s integration to facilitate the energy transition.

Mel Kroon, CEO at TenneT, mentions two essential catalysts of a sustainable European energy future: “Further integration of the North-West European electricity markets” to improve green energy management, as well as “smart, innovative systems” to match future energy demand and supply. Among TenneT’s most prominent international projects are the so called Power Link Island, a North Sea Wind Power Hub to be developed jointly with Danish TSO Energinet, the COBRAcable between the Netherlands and Denmark, or the NordLink cable to connect the Norwegian and German electricity markets. TenneT’s key initiative in terms of smart software solutions is the research on block chain technology fostering local, flexible electricity generation.

The company’s European commitment is emphasised by the opening of a representative office in Brussels in June and the appointment of Ben Voorhorst, Chief Operating Officer of TenneT, as President of the European Network of Transmission System Operators for Electricity (ENTSO-E) in March. As far as TenneT’s operating results in the first half of 2017 are concerned, the TSO reports satisfactory figures, with profits before interests and taxes growing to €478m. Infrastructural investments in the Netherlands and Germany remained on a high level since large-scale grid extension projects, on- and offshore, are being implemented continuously. To help financing these investments in the transmission of the renewables, TenneT has yet again succesfully issued long term green bonds with a nominal total value of €2bn in March and June respectively.

> See TenneT press release (html)
> Open TenneT half-year report 2017 (pdf, 2.58mb)

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Top marks for Danish supply security

18.07.2017

Every summer, TSC member Energinet, the national Danish transmission system operator (TSO), gives a detailed insight into the status of last year’s supply security in Denmark by presenting the annual “Security of Electricity Supply Report”. With an availability rate of electricity of 99.996% of the time, Energinet has maintained the excellent value of the preceding year and continues to rank among the top European countries also in 2016. In addition to this, the number of incidents, near-miss incidents, or failures in the Danish transmission system was consistently low, in spite of the changes within system, primarily due to the energy transition and the ever increasing feed-in of renewables.

Anders Pallesen Jensen, head of Security of Supply at the Danish TSO, comments the good marks: “Energinet is proud of this achievement, but we’re also aware of the future challenges which must be addressed.” This means, that Energinet thoroughly monitors the ongoing evolution, runs analyses, and launches new initiatives – especially in terms of cross-border cooperation including both, infrastuctural and market-based measures. Energinet’s head of Electricity System Operation, Søren Dupont Kristensen, strongly believes that in order to preserve the high level of supply security in the long-term, “the TSOs need to increase their focus on coordinating electricity markets, electricity grids and international connections across borders”.

> See Energinet press release (html)
> Download Security of Electricity Supply Report 2017 (pdf, 6.5mb)

Illustration using the picture “Copenhagen from the top” by CAECA COPENHAGEN (Copenhagen Media Center)

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PSTs stabilise the Czech grid

31.05.2017

The first quarter of 2017 was noteworthy for TSC member ČEPS: The Czech transmission system operator (TSO) put two technically advanced phase-shifting transformers (PSTs) with phase angle regulation into operation in mid-January. Since then, the PSTs have been regulating electricity flows from the eastern part of Germany, thus contributing not only to the stability of the national transmission system, but also preventing the Czech TSO from performing expensive remedial measures.

Consequently, ČEPS was able to save up tens of millions of Czech korunas (CZK). The TSO increased its profit before tax by CZK 235m (about €8.9m) compared to the first quarter of last year and achieved an overall profit of CZK 948m (about €35.9m). In March 2017, the last of altogether four PSTs arrived at the Bohemian substation in Hradec u Kadaně, and all of them are expected to be in full operation by the end of June. Then, ČEPS will be able to transfer the maximum amount of electricity through its transmission system without compromising on the Czech supply security. Jan Kalina, Chairman of the ČEPS Board of Directors, explains that the regulatory parameters of the PSTs will be set up in coordination with foreign partners at the pre-launch phase. Prime objective is to ensure “the operational reliability of electricity networks throughout the region”.

In the first quarterly period of 2017, a total of 16,933 GWh of electric energy was transferred through the national transmission system. ČEPS can also report a historic high load on the power system: On 24 January, the load was going up to 11,769MW, thereby topping the previous record load from February 2012. “The new historical maximum was reached due to a very cold weather”, comments Miroslav Šula, Head of the System Operation Management section of ČEPS. The construction of the new 420kV Vernéřov substation near Kadaň in the region of Ústí nad Labem is also worth mentioning. Since investing into the Czech grid extension also means contributing to the transnational power system on a pan-European level, ČEPS benefited from EU grants of more than €4m for Projects of Common Interest (PCI). The ČEPS investement plan thus respects the TSO’s national responsibilities and also the “fulfillment of European objectives with regard to the safety of the whole interconnected system”, concludes Jan Kalina.

> See ČEPS press release (html)

Picture: ČEPS

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Swiss winter report

18.08.2016

The energy and grid situation in winter 2015/2016 in Switzerland was stressed. The Swiss transmission system operator, TSC member Swissgrid was faced with a tense energy and grid situation owing to a succession of exceptional circumstances leading to very low energy reserves. Yesterday, the TSO published the final version of the Winter report 2015/2016 on how the company managed the difficulties in collaboration with the Swiss energy industry and neighbouring TSOs.

> See Swissgrid news release (html)

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