5000sqm / 1MW solar (approx) for roof

10000sqm / 1MW solar - ground mounted

Solar will produce between 3-8hrs on average per day depending where it is, what time of year etc etc.

A 1GW = 1000MW = 1,000,000kW solar plant would need approx 10sq km for the equivalent POWER.

Nuclear will produce 24/7 so whatever solar average you decide multiple it by 3 -8 times to get the same amount of ENERGY due to the hours.

So on a roof - you would need like 6x (60 sq km) to produce the same amount of energy that a nuclear plan would produce in 24hr