I'd worry that the improved farming techniques will not facilitate a release of land back to wild, but would simply intensify whatever acreage is already farmed + whatever new ground anyone can justify (like anywhere else I'm aware of).
Yes, a lot of people say 'power' when they're talking about 'electricity' loosely.
Your point about "per year" technically going back to power is only applicable if you actually do the x GWh/per year maths. It's common to refer to energy production capacity as 'y kWh per year' (even though the ratio of those two components gives you the average power over that time period).