Option 1:
Get a goat and put up a sign that is is running on that "solar powered
grass"
Option 2:
There are several cordless lawnmowers that run off a battery, so you can
skip the inverter.
Example:
http://www.epinions.com/content_144863563396
You should be able to recharge it off solar panel(s)/change controller.
A little shed with the panel on the roof to hold the mower and charge it
would be nice.
Alternatively, a solar panel sun shade mounted to the mower to keep the sun
off your head while
you artistically curse at the top-heavy monster during mowing. But you
will still need to park it
for a few days to recharge since anything you mount is far to small to run
the mower directly....
-Kent-