Electricity grid expansion - current status, grid costs and interventions

In 2012, it was decided to phase out the use of nuclear power, and in 2022 the last nuclear power plant will be taken off the grid. The loss of power must be compensated for by a rapid expansion of renewable energy sources, which for the most part generate electricity intermittently as well as very unevenly across the federal states. In addition, transmission grids are to ensure power supply over the area of Germany. Read more about the current status in power grid expansion in the technical article by Dr. Klaus Hassmann, spokesman for the Energy Technology Cluster.

How does network planning work?

The expansion of electricity transmission networks is regulated by the Energy Line Expansion Act (EnLAG) and the Network Expansion Acceleration Act (NABEG). Planning takes place in various steps. First, the four transmission system operators prepare a scenario framework. Based on this data, the Federal Network Agency BNA determines the network development plan, whose regional distribution is in turn determined by the network operators. The network development plan is then published and supplemented by an environmental report and results from discussion rounds on a federal requirements plan. The technology for implementing the plan (overhead lines, underground cabling, etc.) is determined after several public hearings. Read more about the power expansion in chronological review here.

2013

The transmission system operator 50Hertz is completing the northern line between Schwerin and Hamburg, and good progress has also been made with the southwestern dome line between Thuringia and Bavaria. The Federal Parliament and Council decides on the South Link route from Schleswig-Holstein to Grafenrheinfeld and the South East route from eastern Germany to Augsburg. The duration of the planning procedures has so far been ten years or more, and the court proceedings five to seven years. The planning of cross-state projects is in one hand at the Federal Network Agency. The Network Expansion Acceleration Act (NABEG) and an additional Federal Requirements Plan Act are intended to speed up the procedures.

2014

Two submarine cables, the Nord-Link direct current cable with Norway and the Hansa Power Bridge between Mecklenburg-Western Pomerania and southern Sweden, are intended to help tap storage potential for imports in Scandinavia. The Nord-Link is being developed by a project consortium Statnett and TenneT/KfW. A decision is expected to be made before the end of 2014, with implementation possible by 2018. A memorandum of understanding has been signed between the companies 50Hertz and Svenska Kraftnät for the power bridge. Implementation is scheduled for 10 years.

2015

TenneT is applying to BNA for federal sectoral planning for the southern link. A demand calculation with new data may give room for negotiation, as less offshore wind power is expected. Additional rework is needed and there are delays. Of 112 route corridor alternatives, 98 are to be studied in depth. The direct current connection from Schleswig-Holstein to Baden Württemberg is not a priority. The EnLAG includes projects with a length of 1876 kilometers. Of these, only 487 kilometers had been realized by June 2015. They were almost completely put into operation (380 kV) or trial operation (220 kV). According to estimates by the transmission system operators, 40% of the EnLAG line kilometers can be completed by the end of 2016.

2016

50Hertz has completed an important north-south transport link ahead of schedule with the Thuringia power bridge and the south-west dome line. Crossing  Berlin, a cable connecting the wind farms in the Baltic Sea was laid in a tunnel. The EnLAG provides for 24 new construction projects with 1800 kilometers of extra-high voltage lines. At the end of 2015, only 614 kilometers had been implemented.

2018

TenneT will quadruple power transmission capacities between Schleswig-Holstein and Lower Saxony to 9.6 GW by rewiring the 380 kV three-phase transmission network at the Elbe crossing. In 2019, the work will be completed. The Ministry of Economics under new leadership wants to accelerate grid expansion with an action plan. By 2015, around 1800 km should have been added - in 2018, not even half have been realized. The addition results from the EnLAG. Of the approved 1150 kilometers, around 800 have been completed. In 2017, the transmission system operators expected 80% completion by the end of 2020, since Q1 2018 only 70%. Of the 22 EnLAG projects, six are underground cable pilot projects. So far, only one 380 kV AC line is in test operation. Network expansion also falls under the Federal Requirements Plan Act (BBPIG) with 43 projects for a total length of 5900 kilometers. These include the high-voltage direct current links South-East and South-Link. As of Q2 2018, around 600 kilometers had been approved, of which 150 had been implemented. 2200 kilometers fall under the responsibility of the federal states. Approximately 1050 kilometers are in the planning approval process. The Ministry of Economics' action plan aims to optimize known acceleration options and simplified planning procedures. They will be supplemented by new measures to be bindingly agreed with the federal states.

What does the expansion of the power grid cost?

2013

The transmission system operator 50Hertz is investing €254 million in maintenance and line construction in 2012. In 2013, expenditures of €400 million are planned, and about €4 billion by 2022.

2014

TenneT spends about 150 million per year on grid stability. Sensitively higher costs are expected if grid expansion does not proceed.

2015

The additional costs for underground cables compared with overhead lines are estimated at a factor of 3 to 8, depending on the terrain and crossing infrastructure, and even 4 to 8 for the three-phase system. The useful life and availabilities (99% for a 500 kV high-voltage direct current (HVDC) overhead line) are lower. Longer repair times apply in case of damage.

2016

A variant for rural, sparsely populated regions is an overhead line for direct and three-phase current mounted on the same poles. They are 15 meters higher than comparable three-phase pylons. One kilometer of hybrid line costs about €2 million, while the direct current line costs €500,000 . The cost of one kilometer of underground cable is €8 to 10 million. Earth cables are more expensive than overhead lines by a factor of 4 to 5. The south link and the south-east link cost €15 billion. Grid fees for extra-high voltage are to rise by 80% at TenneT, 40% at 50Hertz and 12% at Amprion. The reason given is the cost of redispatch, the simultaneous shutdown of renewables in the north and the ramping up of conventional power in the south to stabilize the grid. The costs for this vary from region to region. Grid charges are to be uniform throughout Germany. However, the final word has not yet been spoken on this.

2018

The first direct DC connection with the UK is being planned. The cost of two 500 kV high-voltage direct current lines of 670 km in length with a capacity of 1400 MW through the North Sea is €1.6 billion. Construction is scheduled to begin in 2020 and be completed in 2022, allowing bottlenecks in the German grid to be absorbed and surplus wind power to be transported from Germany to the U.K.

What does redispatch cost?

2013

According to the transmission system operator 50Hertz, the costs for redispatch in 2012 were around €120 million. On 77 days, the feed-in of renewable energies had to be throttled. The demand is: Synchronization of the expansion of renewable energies with the grid expansion.

2016

Due to the missing north-south connections, the redispatch costs of 50Hertz in 2015 were 350 million, in Germany even more than 1 billion €.

Author: Dr. Klaus Hassmann, Spokesman Cluster Energy Technology

The information comes from the trade magazine Energy & Management (e&m).