New sensors in the high-voltage lines will make it possible to measure the temperature and 'sag' of the lines. Using the weather data, the national grid operator can transmit more power than the lines are designed for in favourable weather conditions. These sensors have been installed on the 380 kV (kilovolt) link between Geertruidenberg and Eindhoven. This smart solution provides up to 30 per cent extra transmission capacity across the entire grid. ?
When electricity is transported, the conductors in the high-voltage lines heat up. This heating causes the conductors to sag, which limits the maximum transmission capacity of a high-voltage line. However, the weather can have a favourable effect on the cooling of the conductors. At low temperatures, especially when there is wind, the line is cooled more, resulting in less sag. In such a case, more power can be safely transported.?
In recent years, we have gained experience with this technique, known as Dynamic Line Rating. Initially, it was applied to so-called 380 kilovolt power highways. This year it will be applied on a larger scale, also to 110 kilovolt networks. Throughout the country, special sensors are being installed on eight other connections, which will also enable dynamic operation of these connections in the high-voltage network. Earlier this year, sensors were installed on the high-voltage connections between Groningen and Meeden and between Diemen - Breukelen - Krimpen aan den IJssel, helping to increase the amount of sustainably generated energy available.
Every five minutes, sensors measure the sag and transmission capacity of the high-voltage line. Based on this data and weather forecasts, an IT platform developed by us determines how much additional power can be transmitted over the link, now up to 56 hours in advance. This creates additional space in the existing grid. Depending on the circumstances, this can be up to 30 percent more capacity than the existing capacity, without taking on more risk. Wind determines much of the additional cooling of the lines. For example, Dynamic Line Rating often creates extra capacity when a lot of power is generated by wind turbines.
The Dutch electricity grid is becoming increasingly congested and will therefore be significantly expanded in the coming years. Expanding and upgrading the infrastructure is costly and time-consuming. Grid operators are therefore applying other intelligent solutions to make more efficient use of the existing grid. In addition to Dynamic Line Rating, the 'flight lane' is also being used. This is where solar and wind farms are connected to the contingency reserve.
