Comment Re:Things are actually going to get even better (Score 1) 209
I am not so sure of that assertion. For one batteries are astonishingly efficient, so a big pile of them in one place versus a lot of them distributed out does not seem to make a lot of difference for efficiency. Add the grid losses and the losses needed because grid storage always feeds into high voltage nets and it is not so clear, if the efficiency of grid or personal batteries are better.
When you look at prices, grid storage is quite a lot cheaper, but the assumptions behind grid storage and personal storage are different. While a grid operator wants to make money by loading the batteries when price is low and discharge when it is high, a personal battery storage system is used to store the energy from own generation. As prices for power being fed in are falling while prices for power consumed from the grid are mostly stable or rising, local battery storage is used to change low paying power into saved grid power and so the economics of local storage are very different from grid storage.