* Solar energy is unlimited if there is constant sunlight.

* Darkness and heavy clouds cover the sun

* yes if the sun shines the whole time

*no because the sun goes down, but they do have batteries

Can Solar Power Be Used Everywhere?

www.ase.tufts.edu/gdae/.../renewableenergyecon.pdf

http://www.eia.gov/todayinenergy/detail.cfm?id=1789/