Where could the expansion of renewables be slowed down in the future?

Where could the expansion of renewables be slowed down in the future?

The draft law and its possible consequences

This question has been raised since the draft bill by the Federal Ministry for Economic Affairs and Energy (BMWE) was made public for a “law amending energy industry law to synchronize plant expansion with grid expansion and to improve the grid connection process.” (Link)

This draft proposes the introduction of a new Section 14, Paragraph 1d in the Energy Industry Act (EnWG), according to which distribution network operators would be able to designate so-called capacity-limited substations and line sections if the “technically possible electricity feed-in from directly or indirectly connected plants was adjusted by a total of more than three percent in the previous calendar year.” Such adjustments are also referred to as redispatch. Plant operators are currently compensated for the lost revenue from the curtailed energy volume.

In connection with the proposed amendment to Section 8, Paragraph 4 of the Renewable Energy Sources Act (EEG), however, grid operators will then only be obliged to connect renewable energy plants if they waive financial compensation.

Since project developers and plant operators find it difficult to estimate how often the generation of newly planned solar or wind farms will have to be curtailed by distribution network operators, their financial viability and thus their feasibility in these capacity-limited regions is questionable.

The methodology for identifying capacity-constrained regions

The independent identification of capacity-limited substations and line sections is difficult for three main reasons:

1. The geographical location of power generators' grid connections is not public information, so it is not possible to say exactly which substation or line section they are directly or indirectly connected to
2. Only a few distribution system operators publish plant-specific redispatch data. All others publish redispatch measures only without specific reference to specific plants or not at all, so that geographical allocation is also not possible here
3. The amounts of energy generated by renewable electricity producers are not publicly available, so that the “technically possible electricity feed-in” and the feed-in curtailed due to redispatch must be determined elsewhere.

Instead of specific substations and line sections, the dvlp.energy team therefore identified capacity-limited regions at the administrative community level. The technically feasible and curtailed electricity feed-in was calculated for each electricity producer based on the

• Master data in the market master data register (location, capacity, technology)
• Weather data from nearby stations of the German Weather Service (global radiation, wind speeds)
• Published redispatch measures relating to plants (degree and duration of curtailment)

and was then totaled for the relevant administrative communities in which the facilities are located.

The capacity-limited regions

The regions in which more than 3% of the technically possible electricity feed-in is already being curtailed are mainly located in the northwest of Lower Saxony, Schleswig-Holstein, and Brandenburg, in the northeast of Saxony-Anhalt, and in central and eastern Bavaria.

While the former are mainly characterized by high electricity feed-in from wind farms, in Bavaria the feed-in of solar power is the capacity-limiting factor.

In these regions, the proposed legislation could mean that new renewable electricity producers cannot be financed due to a lack of compensation for lost revenue from the energy quantities that will be curtailed in the future.

In the dvlp web GIS, our users can view the technically feasible and curtailed energy quantities for each administrative municipality, also broken down by wind and solar.

It should be noted that unfortunately no data is available for large parts of North Rhine-Westphalia, Saxony, Thuringia, Rhineland-Palatinate, and Baden-Württemberg.

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