I was going to say seems like a lot to me, that is 2 or three nuclear plants worth. But I don't know anything about Nigeria or the sizing of power grids. So I decided to look it up.

Nigeria is the 6th most populous country on earth with 230 million people in 920_000 km2. for comparison Texas is 700_000 km2 with 30 million people and they are making 65 gigiwatts.

So yeah, that is very low.

Nuclear reactors are in the range of 700-900 MW, afaik. Those 3 nuclear power plants would be pretty big - 6 reactors each.

The other issue is that while Nigeria has a lot of people, is rural, which makes the electricity usage pretty small per capita.