Investigation of capacity during wintertime

Section 5.7.1.5 of the Netherlands Grid Code stipulates that the transmission capacity should be separately calculated for the winter using a quantitative survey, 'winter' having been defined as a consecutive period of 100 days during which the grid components are expected to be subjected to maximum load owing to meteorological conditions. As this is currently still being investigated, the winter capacity has for the time being been set at the same level as the transmission capacity that has been adopted for now.

It should be pointed out, however, that it is not just the loadability of the conductors of the connections that dictates the circuits’ transmission capacity but primarily, that of the substations, such as connectors, current and voltage transformers, switches and separators. Earlier studies have borne out that it is this equipment that dictates the transmission capacity, with replacement entailing risks and significant cost while yielding only a limited increase in transmission capacity.

An additional aspects comes into play where the cross-border interconnections are concerned, in that they comprise a Dutch and a foreign section each of which has its own transmission capacity, which in some cases happens to be lower on the non-Dutch side due to the way in which the connection is put together or is connected to the substation. This will then affect the transmission capacity of the entire interconnection.