Solar Sail pin wheel generator

> I have gotten into an argument with someone, who came up with the
> idea of setting up a Solar Sail as a windmill with rotating about
> a generator.
> His thought process going along the lines of the sunlight provides
> a constant acceleration so the sail will just keep rotating faster
> and faster and generate electricity in greater amounts.
>
> To me it seems intuitive that it would not work, at least not in
> the way he is thinking of, but I am not sure how to go about
> showing that, or showing that I am wrong.

I think that this might just work. But it would have to be
ginormous. I mean, powersat big, or even bigger.

> So does anyone have any ideas about how to work out if it is
> feasible or not ?

Like you, I wouldn't know how to prove your friend right or wrong on
this. I look forward to reading answers from those who *might* know.