flying pigs?
that will never work. they have been working on that for decades. Just because they can fly doesn't mean they will. The most you'll get is a few hours of flying time per day. No one has every gotten a pig to fly more then two hours. No way your going to get 10 hours per day. And, whatever you save on the PV will be literally eaten up by your feed costs.
You need to wait till 2012 when the genetic engineered "blowup" pigs are available. They have an oversized bladder. All you need to do is hookup your hydrogen generator, blow them up, and they will float for hours. Really cool if you get the ones that glow in the dark.
You just need to get a solar detector so you can automate blowing the up in the morning and bringing them down in the evening. Your have to be careful in setting the set point on your hydrogen dump controller so they don't come down too fast. Oh yeah, you'll need to size your tail ground appropriately. A netural/ground bonding might work, but i'm not sure. If it isn't sized right, when you get lightning, you'll give a whole new meaning to "blowup" pig. Not the kind of bacon you want to bring home.
There are a few issues that need to be worked out, but they have a few years yet to do that. And, when combined with the methane collector, it is a no brainer.