solar powered ponds?

Hi,
I'm new to this newsgroup, just doing research to see whether I'm going
to put a pond in. I already bought some whiskey barrel planters to start
off my yard with a water feature to see how it goes. To me, the most
intimidating thing about doing a full pond is the electrical requirements.
Based on my research, even a small pond would require me to hire an
electrician to run a line out into my yard. The whiskey barrel option is
appealing because it seems small enough not to require a pump or filter.
One thing that I would love to do, and I'm surprised that I haven't seen
others doing it, is to power a pond solely with solar power. It seems like
that solution is the most in touch with improving our environment. Yet I
haven't seen any of the pond supply people selling solar powered items, with
the exception of very small fountains and the like. Why don't more people
use solar power? Is it prohibitively expensive, or simply inadequate for
the power demands of most pond systems? I would love to hear if anyone is
using solar power and how they have things set up.

Thanks,
Brian