A Power Quality verification is only necessary when the installation is said to be "likely to disturb the network", notably in the case of the following installations:
- Arc furnaces and rolling mills;
- Wind or photovoltaic production with a capacity of 10 MW or more;
- Power electronics installations (batteries, electrolysers, etc.) with a capacity of 10 MW or more;
- Installations with compensation or filtering means (STATCOM, SVC, capacitor banks, etc.);
- AC/DC railway substations.
The methodology followed for the Power Quality compliance studies is fully described in the Synergrid prescription C10/17 (Technical specifications electricity (synergrid.be)).