Upgrading and expansion of electricity grids

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Germany plans to almost double the proportion of the country’s gross electricity consumption met by renewable energies, from just over 46% in 2022 to at least 80% by 2030. This is to be achieved by erection on a large scale of onshore and offshore wind turbines and photovoltaic (PV) systems [1].

The expansion of renewable energy sources and the decommissioning of nuclear and coal-fired power plants is changing the locations at which electricity is produced and increasing the volatility of electric power generation. For the energy transition to be completed successfully, the electricity grids must therefore be upgraded and expanded.

Electricity is generated from wind power by onshore and offshore wind turbines, primarily in north-western and north-eastern parts of Germany and in the North Sea. It must be transmitted from these locations to the centres of consumption in western and southern parts of the country. To enable increasing quantities of electricity generated from wind energy to be fed into the grid (transmission network) and transported by it and for grid bottlenecks to be avoided, the grid requires new high-voltage transmission lines [2]. 119 grid expansion projects for which legislation has been enacted are currently in progress in Germany, with a total length of almost 14,000 km [3].

The growth in PV systems is resulting in more and more electricity being generated locally. Local electricity consumption is also set to increase as a result of the switch to electromobility. This rising decentralization, together with the higher volatility of electric power generation from renewable energy sources (RESs), requires changes to the distribution grids.


  • What is accelerating the trend, and what is slowing it down?

    Far-reaching measures to create a low-carbon economy (LCE), such as electrification of transport, increased use of heat pumps in the thermal energy market and production of green hydrogen for industry, will increase the demand for electricity between now and 2050, despite considerable improvements in energy efficiency [2]. These effects and the targets stated for the energy transition are likely to fuel the trend.

    Other factors, however, reduce the need for the electricity grid to be expanded:

    Expansion of the transmission and distribution grid follows the "NOVA" principle (the German acronym stands for prioritizing optimization over upgrading and expansion) [2]. Optimizing the grid is preferable to expansion not only owing to the better use of resources, but also in view of the increase in extreme weather events: power supply systems and installations that are able to withstand such events contribute to the stability of the grid and the security of supply. Examples of grid optimization include the use of high-temperature stranded cables and superconductor-based cables. Routing cables underground makes electric power transmission particularly resistant to adverse weather events.

    Another example of grid optimization is monitoring of overhead lines, by which the transmission power of each individual conductor can be adjusted according to the temperature [4]. The use of artificial intelligence to control the transmitted power by means of networked smart sensor nodes is currently being tested.

    Overall, the need for grid expansion is reduced when local power generation facilities are sited close to the locations of consumption, and by consideration of real-time grid status data (instantaneous consumption and power infeed from local generation facilities) [5; 6], i.e. a combination of grid expansion and systems for intelligent distribution grid management. A digital infrastructure (smart grid) is currently being created in which all elements of the electricity grid can be controlled and coordinated to enable maximum energy efficiency and security of supply to be attained, even as the proportion of renewable energy rises [6].

    Storage technologies such as new types of battery or power-to-gas (e.g. hydrogen) will enable surplus renewable energy to be exploited, and will increase the grid’s flexibility and energy efficiency. They offer great potential for decarbonization, and reduce the need for the electricity grid’s expansion and the associated investments.

    Other factors presenting an obstacle to upgrading and expansion of the electricity grids are lengthy, highly complex planning and approval procedures, owing not least to resistance from within society [3]. Shortages of skilled workers and other personnel in the upstream sectors and among operational service providers are also an obstacle to grid upgrading and expansion.

  • Who is affected?

    Upgrading and expansion of the electricity grids primarily affects the power generation and distribution industry. Operational service providers are also affected, specifically the electrical trade and civil engineering companies. The upstream sectors affected are the metal and electrical industries and the raw materials and construction materials sectors.

  • Examples (only in german)
  • What do these developments mean for workers’ safety and health?

    Expansion of high-voltage lines in the transmission grid entails a protracted process of preparation. It also involves, among other things, intensive research and technology development projects, public debate and acceptance studies. Expansion of the distribution grids requires data to be exchanged on a greater scale, and close cooperation between the distribution network operators (DNOs) and transmission network operators (TNOs) [7; 8]. In both cases, conflicts of interest must be resolved in the course of the various decision-making processes. This can create considerable psychological pressure, particularly in combination with time pressure.

    The transmission grid must be upgraded as referred to above. In addition, high-voltage transmission lines must be installed carrying the lower-loss, high-voltage direct current (HVDC), as well as new high-voltage lines for alternating current.

    As yet, the distribution grids are not equipped for the resulting new load processes. Besides construction of new lines and upgrading of cables and transformers [9], the secondary substations, neural network nodes and selected infeeds must in the first instance be upgraded with smart communication, measurement, control and automation technology [10].

    The electrical hazards and the risks of falling associated with the measures described, together with the hazards presented by civil engineering work, are already known, and prevention measures are in place. The research project conducted by the German Federal Office for Radiation Protection (BfS) into "Radiation Protection in the Process of Power Grid Expansion" is intended to answer remaining questions concerning the possible health impacts of exposure below the existing limits to static and low-frequency electric and magnetic fields produced by power lines [11].

    Introduction of the smart grid is an ambitious technological leap in the power generation and distribution system, and may be preceded by planning permission hearings, possibly lengthy. In the accompanying processes, the potential mental stress brought about by work involving other people and a focus on success is also a particular factor [12]. In addition, digitalization of the grid is initially accompanied by uncertainties and changes in the workforce with regard to work activities and the skills requirements. The growing complexity, lack of transparency, and effort required for comprehending grid and operational management tasks as they are increasingly being assumed by artificial intelligence, present obstacles to an in-depth understanding and overview of the interrelationships within the grid and the installations [13]. This may be accompanied by a sense of alienation, loss of competence and/or excessive demands.

    Once the process of digitalization has been completed, however, work becomes easier:

    The smart meter - the heart of the smart grid - enables grid states to be determined in real time. For example, the smart meter gateway (SMGW) provides TNOs with information on instantaneous and pending grid states and on supply and consumption data (for power plant dispatching purposes). This helps to stabilize the network, as it enables TNOs to plan grid management for the hours ahead and avert outages in time by controlling the smart grid [14]. Scope is also created for predictive maintenance, which reduces maintenance and servicing effort and extends servicing intervals [15]. Through the use of intelligent technology across the grid, including for example in secondary substations, faults can be located more swiftly and precisely and bypassed automatically, and thereby cleared more quickly [16]. This enables repair crews to work more efficiently, and reduces stress and time pressure. Automatic fault clearance also means that fewer staff need be on call [15]. The smart grid thus partly offsets the shortage of skilled workers and other personnel.

    The power generation and distribution industry provides critical infrastructure for the body politic. The growth of digitalization and networking in the industry is increasing the risk of cyberattacks and leading to stricter requirements for industrial security and data security. Failures and interference caused by such attacks can be seriously detrimental to public safety and have other dramatic consequences [17].

  • What observations have been made for occupational safety and health, and what is the outlook?
    • As decarbonization progresses, demands are increasingly being presented by planning, decision-making, cooperation and coordination, and also by the use of artificial intelligence, for example in grid management. Against this background, mental stress, caused for example by work with other people, is becoming more important in workplace prevention activity in the power generation and distribution industry.
    • In the course of decarbonization, exposure to electromagnetic radiation is becoming more strongly associated with complex and multi-frequency fields [18]. This applies, for example, to power transmission network installations, data transmission systems and e-mobility. Employees working on many of these sources of electromagnetic radiation are already protected by safety measures. Whether and if so what changes to these safety measures will be required in the future in the form of innovative technologies must be reviewed. Further research is needed to clarify existing and possibly emerging uncertainties regarding the effects of electromagnetic fields on human beings and the environment.
    • The susceptibility of the power transmission and distribution networks to attack rises with the level of networking and digitalization. This makes industrial security an important occupational safety issue in the power generation and distribution industry.
    • Expansion of the power transmission and distribution networks intersects at many points with the expansion of renewable energy sources and ongoing development of storage technologies. The perspectives described for the latter also apply in many respects to the former.
  • Sources (in German only)

    [1] Erneuerbare Energien in Zahlen. Hrsg.: Umweltbundesamt, Dessau-Roßlau 2023 (abgerufen am 22.06.2023)

    [2] Netzentwicklungsplan Strom 2037 mit Ausblick 2045 Version 2023, zweiter Entwurf der Übertragungsnetzbetreiber (non-accessible) Hrsg.: 50Hertz Transmission GmbH; Amprion GmbH; TenneT TSO GmbH; TransnetBW GmbH, Berlin; Dortmund; Bayreuth; Stuttgart 2023 (abgerufen am 25.07.2023)

    [3] Aktueller Stand des Netzausbaus (Übertragungsnetz) (non-accessible). Hrsg.: Bundesministerium für Wirtschaft und Klimaschutz, Berlin 2023, 27.7.2023

    [4] Netzausbau Freileitungen (non-accessible). Hrsg.: Bundesnetzagentur für Elektrizität, Gas, Telekommunikation, Post und Eisenbahnen, Bonn 2019 (abgerufen am 18.08.2023)

    [5] Wirth, H.: Aktuelle Fakten zur Photovoltaik in Deutschland. Hrsg.: Fraunhofer-Institut für Solare Energiesysteme (ISE), Freiburg 2020 (abgerufen am 08.07.2020)

    [6] "Smart Grid" und "Smart Market" (non-accessible). Eckpunktepapier der Bundesnetzagentur zu den Aspekten des sich verändernden Energieversorgungssystems. Hrsg.: Bundesnetzagentur, Bonn 2011 (abgerufen am 18.08.2020)

    [7] Diskussionspapier. Netzbetrieb 2.0. Grundsätze des zukünftigen Netzbetriebs und der Zusammenarbeit von Übertragungs- und Verteilnetzbetreibern. Hrsg.: BDEW Bundesverband der Energie- und Wasserwirtschaft e. V. , Berlin 2018 (abgerufen am 29.10.2020)

    [8] Bründlinger, T.; König, J. E.; Frank, O.; Gründig, D.; Jugel, C.; Kraft, P.; Krieger, O.; Mischinger, S.; Prein, P.; Seidl, H.; Siegemund, S.; Stolte, C.; Teichmann, M.; Willke, J.; Wolke, M.: dena-Leitstudie Integrierte Energiewende (non-accessible). Hrsg.: Deutsche Energie-Agentur GmbH (dena), Berlin 2018 (abgerufen am 29.06.2020)

    [9] Preiß, S.: Elektromobilität, Ladeinfrastruktur und das Netz: Aktuelle Entwicklungen. Hrsg.: EUWID Europäischer Wirtschaftsdienst GmbH, Gernsbach 2020 , 18.08.2020 (abgerufen am 31.08.2020)

    [10] iNES – Intelligentes Verteilnetz-Management-System In: SAG GmbH (Prod.), (2013) (abgerufen am 16.03.2021)

    [11] Das Forschungsprogramm. Hrsg.: Bundesamt für Strahlenschutz (BfS),, Salzgitter 2022, 17.06.2022 (abgerufen am 07.08.2023)

    [12] Barometer Digitalisierung der Energiewende (non-accessible). Berichtsjahr 2019. Hrsg.: Ernst & Young 2020 (abgerufen am 20.08.2020)

    [13] Wolf, S.; Korzynietz, R.; Gaaß, M.; Kraus, T.; Seifert, I.; Bürger, M.; Zinke, G.: Anwendung künstlicher Intelligenz im Energiesektor (non-accessible). Hrsg.: Begleitforschung Smart Service Welt II, Institut für Innovation und Technik (iit) in der VDI/VDE Innovation + Technik GmbH, Berlin 2019 (abgerufen am 30.10.2023)

    [14] Beschluss in dem Verwaltungsverfahren zur Festlegung von Datenaustauschprozessen im Rahmen eines Energieinformationsnetzes (non-accessible) (Strom) (BK6-13-200). Hrsg.: Bundesnetzagentur Beschlusskammer 6, Bonn 2014 (abgerufen am 19.08.2020)

    [15] Roth, I.: Working Paper Forschungsförderung Nummer 073 Digitalisierung in der Energiewirtschaft (non-accessible). Technologische Trends und ihre Auswirkungen auf Arbeit und Qualifizierung. Hrsg.: Hans-Böckler-Stiftung, Düsseldorf 2018 (abgerufen am 12.03.2021)

    [16] Netzinnovationen in Deutschland. Beiträge der Netzbetreiber zur Umsetzung der Energiewende. Hrsg.: BDEW Bundesverband der Energie- und Wasserwirtschaft e. V., Berlin 2016 (abgerufen am 14.07.2020)

    [17] Klärung und Erweiterung des KRITIS-Vokabulars - Kriterien und Vorgehensweise (non-accessible). Hrsg.: Bundesamt für Bevölkerungsschutz und Katastrophenhilfe (BKK), Bonn 2021 (abgerufen am 18.08.2023)

    [18] Strahlenschutzfragen bei der Nutzung neuer Energien (accessible). Zusammenfassung und Bewertung der Klausurtagung 2013 der Strahlenschutzkommission. Stellungnahme der Strahlenschutzkommission. Hrsg.: Strahlenschutzkommission, Berlin 2014 (abgerufen am 09.10.2023)

Contacts

Dipl.-Psych. Angelika Hauke

Interdisciplinary Services

Tel: +49 30 13001-3633


Dipl.-Übers. Ina Neitzner

Interdisciplinary Services

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Fax: +49 30 13001-38001