A nice little toy for someone with little use for a tractor... Really. The ad claims an hour and a half use off 8 batteries, presumably 2 hours with 12. But that's just running it... The more work you put on it the faster the batteries will drain. Most of us have used battery tools and know the score.
The sun is just too diffuse to use for direct power of major implements, although it certainly has proven potential with stationary installations where weight is not a concern and usage is more predictable.
Virginia Tech and other universities have worked for years on solar cars, but hit the same issues. The result is a car that runs, but carried one slim person for a limited time and in a strange position. Advocates say that more development will add normalcy, but any solar vehicle is limited by the amount of sunlight on a finite area - even with impossible 100% efficiency. Electric yes, solar no.
Then there's the issue of manufacturing and disposing of the toxic chemicals in batteries and solar cells...
