The numbers in that article are/were badly wrong. Many numbers are now changed (lines drawn through the old numbers). In particular, the numbers for solar generation have been 'corrected' by factor of 6.7 - the author says he used obviously wrong numbers because the website he copied them from had them wrong.

Although the author has 'corrected' his numbers, he has not modified his conclusions. Someone who does that is not worth paying attention to.

I would like to read a sober and accurate accurate article on Tesla's powerwall, this one is not.