Nu­cle­ar plant back-up op­er­a­tion

Bundesnetzagentur will not order nuclear plant back-up operation

Kurth: "The situation in winter is manageable but tricky"

Year of issue 2011
Date of issue 2011.08.31

The Bundesnetzagentur has today presented its report on whether a reserve nuclear plant as provided for by the Atomic Energy Reform Act (AtG) is necessary. After weighing all the circumstances, the Bundesnetzagentur has decided not to order back-up operation of a nuclear plant for this and the following winter.

"Key is that all the studies now show the transmission network will remain controllable without the use of a reserve nuclear plant, even in the case of exceptional contingency. This is possible thanks to additional conventional power plant reserves being identified since the second moratorium report. We have made sure that power plant 3 in Mannheim (GKM3), power plant 2 in Mainz-Wiesbaden and power plant Ensdorf Block C, facilities that are so important for maintaining voltage in the Rhine-Main-Neckar area, are available in reserve, if need be. A contributory factor in the case of GKM3 has been the willingness of federal state Baden-Württemberg, which has promised to grant the necessary immission approvals. Altogether, we have additional, guaranteed reserve capacity in Germany of 1009 MW and guaranteed reserve capacity in Austria of 1075 MW. Thus the legislative decision to look into a reserve nuclear plant too has encouraged and accelerated the search for alternatives, and was not fruitless in the least", Matthias Kurth, Bundesnetzagentur President, declared at the presentation of the report.

In all the feed-in and load scenarios studied, intervention – sometimes considerable – by the transmission system operators (TSOs) to avert states that are not permitted and that would endanger network stability is needed. "Extreme situations in the network can only be controlled with the help of clear corrections to production based on market outcomes", Kurth stressed. "This requires a tremendous effort on the part of the TSOs and their staff. We commend this engagement. The Bundesnetzagentur is also aware that, even in normal operation, more frequent and more radical intervention in the market will be necessary. Thus nothing has changed in respect of the findings of the first two moratorium reports."

"There will always be risks for security of supply, with or without giving orders for back-up operation. Nobody doubts this. Guarding against every possible risk is impossible, technically and economically. However, with our current levels of knowledge, the main extreme situations for the transmission networks are manageable thanks to the TSOs' intervention instruments and thus there is no need to order operation of a reserve power plant, Kurth declared. "I assume that all concerned will make every effort and take all the necessary steps to secure supply, for instance, to make sure that the reserve capacity offered by the TSOs is soon contractually guaranteed. Also, the official approvals for line build projects are vital and should be issued promptly."

In this connection the Bundesnetzagentur wishes to refer particularly to the need to give top priority to completing the 380 kV very high voltage line from Hamburg/Krümmel to Schwerin. Urgent demand for this line was identified in the legislation, in the Power Grid Expansion Act (EnLAG) of 2009. And finally, the Bundesnetzagentur urges approval of continued operation of Datteln 1 to 3, pending completion of Datteln 4. Delay to Datteln 4 going live may mean that Deutsche Bahn AG's energy requirements in winter 2012/2013 will have to be met from southern Germany, adding to the strain on the transmission networks. The willingness of the government of federal state North Rhine-Westphalia to enter into a dialogue on this is expressly welcomed by the Bundesnetzagentur.

In light of the difficult situation regarding generation in southern Germany in winter 2012/2013 as well, the Bundesnetzagentur would also advise using the experience gained in the coming winter to see whether reserve operation of the Staudinger 3 plant is possible beyond the given closure date of 31 December 2012 until 31 March 2013 at least, as this could ease the situation.

In its report of 26 May 2011 the Bundesnetzagentur had suggested looking into so-called phase-shift operation for the idled nuclear plants. Meanwhile, Amprion and RWE Power have run through phase-shift operation for the generator of Biblis A. Phase-shift will contribute significantly to network stability. The Bundesnetzagentur has therefore called on Amprion and RWE Power to introduce this straightaway; this could be done by January 2012. The costs incurred can be refinanced via the use of system charges.

"The Bundesnetzagentur's reports on the impact of exiting nuclear power on the transmission networks show that the networks have reached the limits of their capacity as a result of the large number of additional transport operations in the last few years and the changes in the structure of generation. Grid expansion is therefore urgently required. The lawmakers have created the possibility of treading new paths with the network development plans provided for by the Energy Act and the new procedures and optional responsibilities set out in the Grid Expansion Acceleration Act (NABEG). These acceleration mechanisms should be used as soon as possible", Kurth urged.

On 11 April 2011 the Bundesnetzagentur presented its first report to the Federal Ministry of Economics and Technology, entitled "Impact of the nuclear power moratorium on the transmission networks and security of supply". On 26 May 2011 it submitted an update.

The second moratorium report was based on the TSOs' initial calculations on the impact on the grid of closing the eight nuclear plants. It found, for instance, based on the TSOs' information at the time, that there was likely to be overload on the lines between the area in and around the Rhine-Ruhr and the area in and around Rhine-Main-Neckar when there was strong load / no feed-in from renewables, as typically happens on a frosty, still winter evening. In a strong load/strong winds situation, by contrast, the voltage would be likely to fall below permitted levels in the area in and around Frankfurt, especially, whereas in a gentle winds /strong load scenario the voltage issues could arise in the Hamburg area. The TSOs thus demanded additional feed-in of 1400 to 2000 MW in southern Germany.

The Bundesnetzagentur had not confirmed such a deficit but did conclude, after examining the TSOs' documents, that it was not possible to rule out a shortfall of some 1000 MW generating capacity in south-western Germany if more than one network resource failed at the same time. This prompted the Bundesnetzagentur to call for a careful check, by mid-August, of the facts put forward. The TSOs have now begun this check.

Parallel to the TSOs' own checks, the Bundesnetzagentur commissioned an expert report to provide an independent, objective review. Addressed in the expert report are the plausibility of the central assumptions, the input parameters, the approach and the assessment of the findings and conclusions.

The Thirteenth Atomic Energy Amending Act of 31 July 2011 constitutes the legislative response and reflects the level of knowledge as on 26 May 2011. The special ruling in section 7(1e) first sentence of theAct derives specifically from the second moratorium report. Under this ruling, the Bundesnetzagentur can order back-up operation of one of the eight idled nuclear plants for the next two winter periods to avert danger or interruptions to the security or reliability of power supply. The Bundesnetzagentur can only make use of these powers until 1 September 2011. It has no authority to do so after this date.

The report presented today on the impact of the exit from nuclear power on the transmission networks and security of supply provides the background to the Bundesnetzagentur's decision not to make use of its powers to order back-up operation of a nuclear plant within the meaning of section 7(1e) first sentence of the Atomic Energy Act.

"The studies of the TSOs, the experts and the Bundesnetzagentur all confirm the findings of the first and second moratorium reports that the situation in the networks has become much more critical as a result of the idling of 8.4 GW of nuclear generating capacity. The scenarios and stress cases investigated – especially the case of exceptional contingency – are indeed extreme but not so unlikely that their possible occurrence can be neglected. We are not talking about purely theoretical cases but about constellations that can actually occur", Kurth said, explaining the situation.

The Bundesnetzagentur's report on the need for a reserve power plant, along with the expert opinion, can be viewed on the Bundesnetzagentur's website.

Press release (pdf / 910 KB)

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