[brudgers]

TANSTAAFL.

You can't get any energy out of a battery until you put energy in ... alas more in than out per the laws of thermodynamics.

[sigkill]

Obviously TANSTAFL but the clear point here is you can burn coal only once. Solar panels + Li-ion can be reused atleast 500 times (assuming standard Li-ion batteries that crap out after 500 full cycles).

[SideburnsOfDoom]

yeah no kidding. It would have been a diversion to mention solar; which Musk is also betting on, not co-incidentally.

Solar in similar: it depends utterly on the whole industrial infrastructure, but is not continually tied to the grid like a power line.