Oh, you're lucky that you can get power to your bee yard! Nice! I have a battery powered fencer, Patriot PBX50 which is 0.5 joule, and apparently 8000 volts without any load. You can get a similar fencer with A/C input. I don't have a solar charger and I can't reasonably get power out to my bee yard, so I just charge the battery every once in a while.

Only been a few years and it has worked thus far. I'm in Vermont USA and I see bear sign regularly on my property and have seen a bear in the flesh once. Also, for what it's worth, I bait the fence with cans with peanut butter in them.

I also use ratchet straps to strap the hives down! I figure... If they get through the fence, I don't want them getting a reward, cause... They'll be coming back, and charging through the measly fence forever.