100% green might look like sickles, scythes, spades and shears. human power. supplement it with a small herd of goats and llamas. it would be quiet, clean, and completely renewable.
batteries are really the weak link in 'green' power. they are toxic, inefficient, and cumbersome. I have been living off-grid for the last 8 years, and my
experience is that photovoltaic itself, is great. if the sun is shining, and you can take the power straight into your tool, it is a beautiful thing. but trying to store large amounts of power, particularly to utilize fairly conventional tools, is not so good. on a good day, you lose 30% efficiency moving the electricity from a solar panel to a battery and back to a tool. if you are trying to store the power for long periods of time, such as through a cloudy week, it sure seems like the efficiency plummets. driving around a sizeable
enough bank of batteries is no light load, those 6 volt L-16 batteries weight a good 60 pounds each. to run a landscaping crew would take a lot of batteries, which is basically a lot of lead plate and battery acid. additionally, if you want your system to last more than a year, you really cant be draining your batteries down under 50%. so you need to double, or even triple the anticipated size of your battery bank. it becomes cost prohibitive, and impractical to transport. goats on the other hand....
I really think we need a reconsideration of 'green'. a lot of things are called green when they are really just shifting the pollution from one form to another. until efficient and non-toxic batteries are invented, we are just 'greenwashing' our alternative power ambitions.