The Flamanville EPR is designed to have an electrical output of around 1,650 MW once fully operational. However, the connection to the grid at 25% capacity is part of the cold functional tests and gradual ramp-up process, which ensures that all systems are functioning correctly under real operating conditions before the reactor is brought up to full power. This step allows engineers to monitor the reactor’s behavior and safety systems, making sure everything operates smoothly before the reactor reaches full capacity.