That's by far the biggest consideration, most likely. Having a ton of hydro is a godsend: you have extreme amounts of energy, but it's hard to export so you can't really hit the resource curse. It can still be a bit of a factor (because high-electricity business e.g. aluminium smelters) but nowhere near as bad as oil/gas.

Just to be clear, 95% of electricity in Norway is from hydro. Not 4.95%