According to provisions for system responsibility in the power system (FoS), Statnett shall define Elspot/Elbas areas (§5) as part of managing:
- Major and long-term operational congestions occurring in the regional and central grid system.
- Foreseen energy deficit situations in defined geographical areas.
During the next years many changes will occur in the Norwegian power system. Because the changes will come with short intervals, Statnett has to see all changes as a whole to:
- always have a suitable area division on short and long term.
- minimize the number of area changes in each geographical area. This has also been an important feedback from the market participants.
Statnett has found that the best way to provide predictability on this issue is to make a prognosis on how Statnett foresee the area division for the next years. The prognosis will be updated when needed. The detailed information about each change will come in separate Exchange Informations.
This prognosis will cover the expected changes from 2013-2016. Failures, energy deficit situations, changes in commissioning dates or other new information could change the prognosis or lead to area divisions that are not mentioned in the prognosis.
The changes in the Norwegian power system we have taken into account in this prognosis are:
- Higher capacity due to commissioning of new cables over the Oslo fjord (Rød-Hasle), November 2013
- Commissioning of 420 kV Sima-Samnanger, December 2013
- Skagerrak 4, HVDC-cable, December 2014
- Commissioning of 420 kV Ørskog-Høyanger, 2015
- Commissioning of 420 kV Høyanger-Sogndal, 2016
- Higher production in small scale hydro power plants, especially in the Western part of Norway
Area division December 2013 to 2015
In December 2013 420 kV Sima-Samnanger are planned to be commissioned. The background for establishing area NO5 in March 2010 was the foreseen energy deficit area in Western part of Norway. The area NO5 has also been useful to handle congestions during surplus situations, especially in periods with high production in small scale hydro power plants.
Statnett's assessment is that import capacity after the commissioning of Sima-Samnanger is high enough to avoid an energy deficit situation, but still export situations could lead to long-term congestions. Increase in the number of small scale hydro power plants will worsen the congestions. With Sima-Samnanger the congestion is expected to occur closer to the Oslo region than the situation today. NO5 will consequently be larger than today, with the following interface to other areas:
NO5-NO1, with the first mentioned node in NO5:
420 kV Dagali-Ringerike
420 kV Nore1-Sylling
420 kV Usta-Ådal
300 kV Nes-Sogn
300 kV Hemsil 2-Sogn
NO5-NO2, with the first mentioned node in NO5:
300 kV Mauranger-Blåfalli
NO5-NO3 (as before)
132 kV double busbar at Åskåra, with one busbar in each area (NO5 and NO3)
Area division 2015 to 2016
In Exchange Information 24/2013 Statnett published the following:
"Due to the planned commissioning of the new 420 kV line between Ørskog and Høyanger in the North-Western part of Norway, a change in the Norwegian Elspot/Elbas area definitions will take place during 2015. The current interface between areas NO3 and NO5 will be moved from the 132 kV double busbar at Åskåra to the 132 kV lines Mel-Fardal and Høyanger-Fardal."
This is the most likely interface also after the commissioning of 420 kV Sogndal-Høyanger in 2016.
Other issues that have been analyzed
- Higher capacity due to commissioning of new cables over the Oslo fjord (Rød-Hasle), Nov 2013.
- Skagerrak 4, HVDC-cable, Dec 2014.
NO2 was established in January 2010 to handle the congestions caused by the reduced capacity on Rød-Hasle. New cables on Rød-Hasle will be commissioned in November 2013. Statnett will not merge the areas NO1 and NO2 for three main reasons:
- In December 2014 Skagerrak 4 will be commissioned, and there are two more HVDC-links planned in 2018 and 2020. This will in periods cause more transit through Southern Norway: import from Sweden combined with export on the HVDC-cables, or import on HVDC-cables and export to Sweden. Statnett consider today's interface between NO1 and NO2 to be suitable to handle transit.
- Congestions due to planned outages on lines connecting Western and Eastern Norway can be handled in the planning phase without reducing capacity NO1-SE3.
- NO2 in combination with an extended NO5 could reduce the extent of capacity reductions NO1-SE3 caused by high consumption in the Oslo region (Oslolast) in periods where the physical congestion is on the Western side of the Oslo region.
In Exchange Information 30/2013 Statnett announced that without outages in the grid export capacity reductions up to the total of 400 MW on Skagerrak (NO2-DK1) and NorNed (NO2-NL) are expected to be needed in the period from the SK4 is put into operation at the end of 2014, until the planned increase of capacity from Kristiansand to Saurdal is completed. Provided that the necessary permissions are given, the building of the Western corridor from Kristiansand to Saurdal is planned to be finalized in 2018. In addition to this capacity reductions caused by ordinary maintenance work will occur.
Statnett has analyzed if a change in elspot area division could be suitable to handle these long lasting congestions. The conclusions so far are that these congestions could not be handled by elspot areas. The reason is that the total capacity will differ too much from hour to hour depending on whether the physical congestion appears in the Eastern or Western corridor. A suitable elspot area division for handling export situations will therefore not be suitable in import situations.
Statnett has an ongoing project with flow based capacity management. A possible introduction of flow based, will probably lead to changes in the elspot area division. Flow based capacity management is not expected to be finalized in the prognosis period 2013-2016.
Lysaker, 1 October 2013
For further information, please contact Statnett:
Tom Tellefsen, Senior Vice president, System operation, + 47 905 36827
Hallstein Mæland, Senior engineer, National Control center, + 47 23 90 32 43