Energinet, the Danish national transmission system operator, is working on a pilot project under which, using a temporary grid connection technique, it plans to bring online over 1 GW renewable energy up to 2 years ahead of schedule.
The pilot project has been approved by the Danish Supply Authority to bring the 6 projects online quicker.
The idea is to connect 1.135 GW solar and solar-wind hybrid projects directly to overhead high-voltage lines using temporary connections resembling crocodile beak, which it says is 'something entirely new.' Power generated by the 6 projects will be sent directly to the electricity grid without having to go through a high-voltage substation.
The temporary connection infrastructure will be more sophisticated than the traditional crocodile beak equipment. Energinet explains that the process will involve placing a temporary electricity mast between 2 masts on an existing overhead line.
A cable from the solar park will be screwed directly onto the overhead line with a T-branch which can be supplemented with switching equipment on a mobile trailer or something similar. The process should be such that it allows the electricity grid to be able to disconnect and interrupt electricity production to maintain system and supply security.
"In many places in the country, the high-voltage stations where new solar parks and wind turbines are connected are already full, and it may take up to 4-6 years to expand the stations or build completely new stations. Therefore, last year we decided to test new solutions with temporary connection to reduce the grid connection time," said Director of Energinet Eltransmission, Henrik Riis.
The agency does see a 'slightly increased risk of more unstable operation in the electricity system,' but its assessment is that it will be safe on special 150 kV and 132 kV overhead line sections. The solution is temporary though as it will switch to a high-voltage substation for a permanent connection as soon as it is ready.
Energinet explains, "The solution also implies that it may be necessary to limit the electricity production from the plants in periods of generally high electricity production. For selected production facilities, it is also a condition that the production facility may only supply part of its maximum capacity in order not to overload the overhead line to which the production facility is connected."
Energinet's approval of the pilot project will enable the 6 projects by 4 producers, namely Copenhagen Green Energy, NRGI Renewables, Eurowind Energy and Better Energy, to come online, possibly in autumn 2025.
Once Energinet approves a plan for the temporary safe connection of their projects, to be paid for by the electricity generators, the latter can sign a grid-connection agreement.
The pilot's success will decide if the transmission operator wants to offer temporary connections to future solar and wind farms as well.
Denmark needs to become fossil fuel free by 2050 with the help of renewable energy, majorly wind energy, with solar installations steadily growing. At the end of March 2023, the country had a cumulative installed PV capacity of 3.25 GW, including 236 MW deployed in Q1/2023 (see Denmark's Solar Installations Growing).