Solar power or nuclear power?

>
> > [snip] Is the surface of the Moon the best place to put a power
> supply for a lunar base ? [snip] The power can be beamed from L1 there
> to the lunar surface. [snip] <
>
> Or, a big, dumb mirror (BDM) can be put in L1 and a lunar base more or
> less underneath can be in sunlight all the time.
>

That does not work well for two reasons.

First, we need to focus the energy into an area only a few kilometres
across at most, this requires precision in the mirror surface to within
about 1/10th ( 0.1 ) of a wavelength, aka "tenth wave" precision. The
longer the wavelength, the easier this is to do. Getting 0.1 wave
precision at optical wavelengths is extremely difficult. Doing it at
microwave frequencies is much much easier.

Second: the conversion efficiency from optical light to electricity is
rather poor, at best 20%, more likely 10 to 15 %. Microwave covnersion
efficiencies are much higher, 90ish %. The figure of merit we need to
achieve is maximum electricity delivered for minimum weight soft landed
on the lunar surface. Microwaves will be better than optical light by
at least an order of magnitude.