I have a cordless electric string trimmer with a NiCad battery. It's the most fantastic thing in the world. It starts at the touch of a button; it runs completely clean and virtually without noise. There's only one thing wrong with it, and that is, it doesn't work. Apart from that, I love it.
I was intrigued by the propane fueled weed whackers that were on the market a few years back. No mixing fuel for the 2-stroke motors, no carb issues from the ethanol content.
But they disappeared pretty quickly, looked like from reliability issues.
There’s a lot of good stuff coming out of green tech. But building it and buying it just for the sake of being “green” is a nonstarter.