Germany is looking to accelerate energy transition driven by geopolitics and energy security in addition to achieving its climate goals under Energiewende (with the target to reduce greenhouse gas emissions by 80-95 per cent by 2050). The Federal Ministry for Economic Affairs and Climate Action or Bundesministerium für Wirtschaft und Klimaschutz (BMWK) recently announced that it is working on amending the Renewable Energy Sources Act (EEG) to ensure that the electricity sector becomes climate-neutral by 2035 rather than at some point ‘before 2050’. To become independent of Russia and other countries in terms of energy supply, the country intends to exit fossil energies sooner rather than later. For this, expansion of renewables will have to take place at an exponentially higher rate. By 2030, solar capacity has to quadruple to 200 GW, onshore wind capacity will have to almost double to 110 GW while offshore wind capacity will increase by four times to 30 GW. Offshore wind is further proposed to be increased to 70 GW by 2045.
The increasing share of clean energy resources in power generation and decreasing conventional sources is already putting immense pressure on the country’s grid in terms of network and in maintaining demand-supply balance. In the emerging situation, the country’s priority is to make a smooth transition to clean energy with flexible energy systems and a robust transmission network.
The recently approved National Development Plan or Netzentwicklungsplans (NEP) 2021-35 by Germany’s Federal Network Agency, Bundesnetzagentur (BNetzA), tries to address these challenges by focusing on creating network expansion opportunities and paving the way for meeting climate neutrality goals.
The four German transmission system operators (TSOs)—50HertzTransmission GmbH (50Hertz), Amprion GmbH, TenneT TSO GmbH and TransnetBW GmbH—submitted the first draft of the NEP2021-35 in January 2021 to BNetzA for approval. Based on inputs from stakeholder consultations, the TSOs submitted a second draft in April 2021, which was subsequently approved in January 2022. While the two previous versions of the NEP (2017 and 2019) targeted the year 2030, the 2022 NEP focuses on 2035. The plan outlines the grid expansion and optimisation that is necessary up to 2035 to reach Germany’s climate targets. It also defines the necessary offshore transmission links.
Although the plan has been formulated considering the federal government’s previous goals of accelerating the expansion of renewable energy, it serves as a good starting point for the TSOs, which will also have to accelerate their transmission development efforts to meet the new proposed climate goals.
The 2021-2035 scenario framework for the NEP 2021-2035 contains four scenarios – three of which describe development paths up to 2035 and the fourth outlines the scenario up to 2040. As per the three scenarios till 2035, electricity consumption would range between 639.8 TWH and 686.9 TWh whereas the fourth scenario forecasts consumption to go up to 688.6 TWh by 2045.
The scenarios provided for in the NEP take into account the national ambitions related to sector coupling (including heat, transport, gas and industrial sectors), development of electromobility and hydrogen strategy. Over 70 per cent of the electricity consumption would be covered by renewable energy by 2035 and over 75 per cent by 2040. By 2045, the conventional power plant fleet would consist of gas-fired power plants, which will be operated in a CO2-neutral manner. The 2035 scenario also reflects an increasingly flexible energy system with abundant renewable energy sans nuclear energy and largely without coal-fired power.
Network Development Plan
In terms of network additions, the approved NEP includes 6,350 km of transmission line network as against the 6,650 km submitted by the four TSOs in the draft (see table). Of this approved length, 2,600 km will be new alternating current (AC)/direct current (DC) lines, 250 km will be DC interconnectors, 50 km will be AC interconnectors and 3,450 km will be for AC grid reinforcement.
This is in addition to 9,900 km of transmission network previously approved under Bundesbedarfsplangesetz (BBPIG) or the Federal Requirement Plan Law (2013), and the Energy Line Extension Act (EnLAG) (2009) (which were enacted to expedite transmission project implementation in the country). This comprises 5,250 km of Startnetz (or start network), which comprises transmission projects that are already in the planning approval stage or under construction, as well as 4,700 km under Bundesbedarfsplan or the federal requirement plan.
Table 1: BNetza-approved transmission network in NEP 2021-35 (km)
|Particulars||Proposed by TSOs||Approved by BNetzA||As per federal requirement plan (and Startnetz)|
|AC new build||500||450||200|
|DC new build||2,150||2,150||1,450|
|AC grid reinforcement||3,700||3,450||2,800|
Status of BBPlG and the EnLAG projects
Although previously approved projects under BBPIG and EnLAG receive priority treatment in the permitting process, their progress has been slow. As of September 30, 2021, BBPlG and the EnLAG included 101 projects with a total length of 12,241 km. Of these, only 22 projects were fully completed, six were approved for all sections and 54 projects were still in the approval phase. For 19 projects, the first applications for federal sectoral planning or for a regional planning procedure were still pending as of September 30, 2021.
Individually, there were 79 projects under BBPIG with a total line length of 10,414 km, whereas EnLAG comprised 24 projects totalling 1,827 km of line length. Around 62 per cent of the projects under EnLAG had been completed as of September 30, 2021, whereas only 7 per cent of the BBPIG project had been completed. The TSOs have attributed the delays to prolonged bureaucratic procedures and the lack of a streamlined procedure for grid expansion.
Germany has planned key high voltage direct current (HVDC) north-south connections to bring wind power from the North Sea and Baltic shores in the north to industrial hubs in the south. These include the ±525 kV Emden East–Osterath and ±380 kV Osterath–Philippsburg lines under HVDC Corridor A, the ±525 SuedLink under HVDC Corridor C, and the ±525 SuedOst Link under HVDC Corridor D. While these large power highways were scheduled to be completed by 2025, most of them are facing delays. This can be attributed to the fact that major parts of the connections are to be put underground. Further, lengthy administrative and permitting procedures as well as local opposition are also hindering project implementation.
In the latest plan, BnetzA has confirmed two additional HVDC transmission lines. One of these will be implemented by Amprion wherein an HVDC connection with a nominal output of 2 GW will be constructed from Suchraum Rastede (Lower Saxony) to Bürstadt (Hesse). As part of the project, a multi-terminal converter at the grid connection point in Rastede will also be constructed. The other ±525 kV HVDC connection (Heide–Klein Rogahn) will be implemented jointly by 50Hertz and TenneT. It also includes an innovative multi-terminal hub planned in Heide together with two offshore connection systems from the North Sea, and a converter in the area of Klein Rogahn near Schwerin.
In addition to augmenting the onshore grid, the development plan also focuses on offshore connection systems, including commissioning years and connection points on land. Compared to the previous plan, BnetzA has stated that 11 additional connection systems in the North Sea and Baltic Sea will be required by 2040.
These are needed to meet the statutory targets for the expansion of offshore wind energy to 20 GW by 2030 and 40 GW by 2040 according to the WindSeeG or Wind Sea Act. (Notably, as mentioned above, the government is now considering revising these targets upwards to 30 GW by 2030 and 70 GW by 2045). As of September 30, 2021, the starting grid (or Startnetz) had a capacity of around 9.8 GW in the North Sea and around 1.9 GW in the Baltic Sea. It includes connection systems that have already been put into operation or have been commissioned or would link up wind farms that have been awarded.
Future offshore wind farms will mostly be connected with DC coupling via multi-terminal platforms. By using this technology instead of individual point-to-point connections, the grid can be expanded more efficiently and cost-effectively. The plan confirms nine offshore wind connections with the latest 2 GW, ±525 HVDC technology, which will offer more than twice the transmission capacity of the 900 MW, ±320 kV HVDC systems that have been common in Germany to date. These offshore ±525 HVDC systems will be commissioned by 2035 and be developed by the three TSOs – five by TenneT, three by Amprion and one by 50Hertz. Four more such systems proposed by TenneT for the period beyond 2035 have been confirmed by BNetzA with reservations. These are expected to be studied further and confirmed in the subsequent plans.
Meanwhile, TenneT recently invited tenders for the construction of sea and land stations for three (BalWin1, BalWin2 and BalWin3) grid connection systems under its 2 GW programme in a bid to speed up offshore wind deployment, combining wind power connections, coupling of energy markets through interconnections, and smart integration into the main onshore grids. The concept’s goal is to have fewer platforms and land stations, and a bundled cable design.
New battery storage pilots
BNetzA has also approved three grid booster systems to be set up in Audorf/Süd in northern Germany, and Ottenhofen and Kupferzell in southern Germany, to reduce congestion management costs by enabling greater utilisation of the transmission grid through reactive operation. The grid booster pilot systems are battery storage systems that are integrated into the TSO control systems to test and implement a new grid operation management technology. In this respect, the battery storage systems are only available for grid operation and not for electricity trading. Initially, the TSOs plan to include a few selected lines and wind farms in the concept. This will be followed by a gradual expansion to other wind farms and lines by 2030, so that its usage can be extended to the entire transmission grid by 2030.
As per the second draft 2021 version of NEP 2035, the German grid requires an onshore network investment of between EUR74.5 billion and EUR79 billion by 2035 (depending on the scenario) and EUR80 billion by 2040. Majority of the investments will be made in AC Zubaunetz (or extension network), which are required to meet the transmission needs of coming years, and in DC Startnetz. This amounts to EUR22 billion to EUR23 billion and EUR20.3 billion in each of the two categories respectively across all three scenarios up to 2035. Meanwhile, about EUR18.8 billion will be invested in AC Startnetz and around EUR14 billion to EUR17 billion in DC Zubaunetz, depending on the scenario.
In addition to the above, a substantial part of the investments will be made in the offshore network ranging from EUR33 billion to EUR38.5 billion by 2035 and EUR55 billion by 2040. Majority of the offshore grid investments will be on DC cable systems and stations. Around EUR5 billion will be invested in the Startnetz and only EUR1 billion in AC cable systems and stations across all scenarios.
Challenges and Way Forward
Germany’s electricity grid is already under immense pressure to make full use of all the renewable power it generates. Due to a shortage in north-south power connections, German grid operators frequently have to resort to redispatch measures and feed-in management, expensive interventions that require the curbing of renewable power input and ramping up of power stations to balance out bottlenecks. The delays in the planned north-south corridors to transmit the majority of upcoming renewable energy in the north to the consumption centres in the south is a cause for concern and needs to be expedited.
Germany faces the challenge of making the transmission grid capable of accommodating the huge influx of intermittent renewable energy in the coming years, particularly to meet its new proposed 2035 climate neutral goals for the electricity sector. It is acknowledged that a robust, flexible and resilient electricity grid is the backbone of a successful energy transition and hence timely completion of the planned network expansion is critical for a smooth transition.
Figure 1: Status of BBPIG projects as of September 30, 2021
Figure 2: Status of EnLAG projects as of September 30, 2021
This article has been sourced from Global Transmission Research and can be accessed here