> A 50×50 km square would be 2500 km². We're talking about 52 km², which is a 7.2 km × 7.2 km square. Shitty dimensional analysis strikes again!

According to the parent poster, those 52 km² are needed for 1GW. France needs around 50GW, 50 times more power and area, ergo 2500 km².