Sources of Hydrogen and Oxygen for settlements

Quoting makenamicro :

> --- In spacesettlers@yahoogroups.com, Ed Minchau
> wrote:
> >
> > >
> > When building a solar power satellite in orbit, we are
> > not limited in size even though such a structure would
> > probably be pretty flimsy. It could be a parabolic
> > reflector say 100 km in diameter. The power beamed to
> > rectennae on the earth from such a device would exceed
> > the total of all commercial nuclear power produced
> > today.
> >
> > Ed
> >
> I take it that sidelobe losses are acceptable due to the free solar
> energy. Good concept, as long as global warming is prevented.
>

The last article I read on the subject said that 87% of the energy would be in
the main lobe.
B.