Do we already have the solution to global warming?

Somehow there is this pervasive idea out there that somehow we need to develop this technology. With just a modicum of research it has become obvious to me we’ve already had the solutions for some time but have not put begun to put such solutions in action.

“I’d put my money on the sun & solar energy. What a source of power! I hope we don’t have to wait until oil and coal run out before we tackle that.” Thomas Edison, 1931

Why is a low starting torque bad for a wind turbine?

Hey. I’m doing a proposal project for my technical writing class and I’m doing it on wind turbines. What I would like to know is why I have been reading that a low starting torque is a detrimental quality to a Darrieus-type vertical axis wind turbine. Wouldn’t this mean that the turbine can start very easily and generate power more often? Does it have something to do with a lot of variability in the generator‘s speed because the turbine can start generating power so easily? Thank you.

How to make a cheap, nontoxic solar cell (ok to be inefficient)?

Current high-efficiency solar cells are apparently still bad for the environment (manufacturing) How would you make at home a cheap nontoxic solar cell using common materials? It’s ok if it is not very efficient, but I was wondering if it was possible at all — maybe just to power air conditioner.

How the sun can produce heating directly in solar heating?

and how the sun can prouduce electricty usin solar cells?