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Plants and Networks

Due to the energy revolution and especially the expansion of renewable energy, network operators are being forced to integrate many decentralised power plants into the network, some of which are dependent on the weather. Digitisation has given us the means of creating an intelligent energy system. In this regard, network operators are legally obliged “to, where economically reasonable, operate, maintain, optimise as necessary, strengthen and expand a secure, reliable and high-capacity energy supply network without discrimination” 1. Specifically, therefore, we are obliged to maintain network stability and security of supply.

1 German government. Energy Industry Act (EnWG), Federal Law Gazette, 2005

Plants and networks
Network stability and security of supply *NFS*

Concept

There are two electricity distribution network operators in the EWE Group: EWE NETZ operates electricity and gas networks in north-western Lower Saxony and gas networks in areas of Brandenburg and Mecklenburg-Vorpommern; wesernetz is the network operator in Bremen. Both are facing different challenges. Whereas EWE NETZ largely operates inland and has to integrate a large number of renewable energy power plants there, wesernetz has to meet the new requirements of an urban area such as the growing significance of e-mobility in the transport sector.

For our customers, the reliability of the supply and in turn the stability of the network in Germany and Europe are what count. Therefore, we gauge the unavailability of the electricity supply, i.e. the average duration of all supply disruptions experienced by an end consumer connected to the network of a network operator in one year.

In order to ensure the necessary network stability and security of supply, the technical conditions such as voltage, current, short circuit current and reliability of supply are regularly tested. Besides the economic aspects, adherence to such thresholds is a key planning criterion for our measures.

Additionally, the ageing behaviour of the equipment is monitored in order to control network stability and security of supply. Damage is assessed systematically with damage codes so as to identify any increase in disruption frequency early on.

The reliability of the supply is tested annually and reported to the German Federal Network Agency and the Network Technology / Network Operation Forum (FNN) by 30 April each year.

Measures

  • For the first time, in line with ISO 55000, the 2017 budget plans were based on asset simulations that can simulate the ageing of the network over a number of years. From these results, we derive investment measures through which we can control the condition of our assets and ensure reliable network operation.
  • EWE NETZ was one of the first network operators in Germany to apply a peak cap at a substation in Manslagt. This makes it possible to connect around 50 per cent more renewable energy to the network with no expensive cable network expansion measures.
  • EWE’s demonstration project ‘enera’ creates an intelligent energy system based on renewable energy in a model region (see ‘Our Strategy’). As part of ‘enera’, a flexibility market is being developed in order to improve the coordination of flexibility and support network stability. This is expected not only to lead to better conditions in EWE’s own network, but also contribute to the stability of the networks of upstream network operators.
    For more details about enera see chapter ➞ Our strategy
    For more details, see ➞ Combined management report / Report on risks and opportunities / Legal and compliance risks
  • In the ‘Green Access’ project, EWE is working with partners in industry and the business world to test current medium and low-voltage network automation solutions with a view to creating a stable, reliable distribution network.
In 2017, the unavailability in the grids of EWE NETZ, wesernetz Bremen and wesernetz Bremerhaven was 5.8 minutes per customer on average (2016: 5.5 minutes) 2. The average in Germany was 12.8 minutes in 2016 3.

2 As the unavailability figure is first calculated for the purposes of the non-financial statement and then reported to the German Federal Network Agency by 30 April, we have calculated a forecast based on the average values from 2013 to 2016 for the current 2017 report

3 Source: German Federal Network Agency

Network lengths

As links between decentralised energy generation and consumption, our energy networks are a crucial factor in an efficient, reliable energy supply. Our telecommunications network, which we are continuously expanding, serves as the basis for our full range of telecommunications services.

As links between decentralised energy generation and consumption, our energy networks are a crucial factor in an efficient, reliable energy supply. Our telecommunications network, which we are continuously expanding, serves as the basis for our full range of telecommunications services.

Network lengths in km1 2017 2016 Change %
Power 93,800
93,300 0.5
Gas 73,100 72,000
1.5
Telecommunications 40,300
39,100
3.2
of which copper cable 15,300
15,200
0.2
of which fibre optic 25,100
23,900
5.1

1 The network lengths here deviate from the management report. They are based on the Group as a whole, whereas disclosures are by segment in the management report