[SideburnsOfDoom]

You can get energy out of a lithium battery several times, which puts it well ahead of tearing holes in the earth to mine coal.

No, it's not permanently "off the grid" as it depends utterly on the whole industrial infrastructure, but it not continually tied to the grid like a power line running to a coal-fired power station.

[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.