Comment Re:Ah yes, cheap batteries (Score 1) 100
You're not going to Gish Gallop your way out of this one. You're the one who brought up your personal experience with the price of batteries at the *hardware store* as proof that batteries have not gotten cheaper. I'm actually being charitable in assuming you're talking about shopping for primary cells; if we're talking *rechargeable* cells the argument is even stronger because they are recharged over and over again which means the steady increase of capacity and lifespan in secondary cells over the decades dramatically lowers your lifetime costs.
As documented in my links above, the cost per energy stored of secondary storage has gone done dramatically in the past twenty years, over 90% since 2000. As for why the Tesla Powerwall isn't dirt cheap yet, customers report waiting months from order to delivery; Tesla already has more customers for this product than it can handle at the current price, why would they drop it? This is Tesla milking the early adopter market segment for a product that they can't produce in high enough volume to sell to the pragmatist market segment.
In any case we're not talking about home storage, we're talking *utility* scale grid storatge with is three orders of magnitude larger. There have been economically successful grid storage projects for years now. Hornsdale in Australia earned back its construction costs in just two years [source]. That's probably close to an ideal econmic situation for grid storage, but as costs continue to drop more and more projects that wouldn't quite clear the normal profit bar will become economically feasible.