There's been a lot of ideas and feedback and I figured I'd throw my two cents in, not sure if these have been mentioned yet, apologies in advance if they have.
Automatic energy replenishment.
Not a lot, just enough. Maybe one point every hour. Between that and picking up an item on the map that would give everyone 34 energy each day. That's enough to keep people playing, but not enough to keep people away from inns and possibly purchasing the upgrades.
Energy with level up
Every time you hit a new level, give 50 energy. Keeps people motivated in moving up the ladder
Max energy increase with level.
Pretty simple, you go up in level you get a higher energy cap, maybe every 5 levels you get one higher energy max
Maybe this can be a purchased or a really rare drop but an object that would let you bank energy. So you could transfer your energy into it at a limit (say 5o or so) and then you can farm for more. This would help people in the rural areas that don't have as many inns/greenhouses nearby so that when they head into town they can load up