Operational
When the total capacity of the NorNed HVDC link (700 MW) has been allocated but not nominated, a capacity of 0 MW will be nominated in the Statnett and TenneT system. Who will take care of the ramping, given the ramping rate of 600 MW/h?
TenneT and Statnett will solve this by means of redispatching, for example.
The ramping constraints is regulated in Nordel, see Exchange information no 53 2007 on the Nord Pool Spot website. The reason for the restriction is to have a secure operation of the synchronous Nordic power system. If the flow on all HVDC cables between Nordel and UCTE were changed at the same hour shift, the total change of flow would be about 8000MW within a few minutes. This constraint would also have been applied for an implicit auction solution and is not particularly connected with the proposed explicit auction sloution. The Nordic TSO's are looking for new arrangements to be able to reduce the impact from ramping on the market in the future.