$1 / Kwh grid storage?

Here's a group who've figured out a way to make a flow battery for which the chemical costs are only about $1/Kwh (the finished battery would doubtless be more, but still...), and the chemicals are completely plentiful (no barrier to worldwide grid storage). A bit light on the life cycles so far, but expect them to figure out some nano coating or chemical reprocessing or some such within a few years. It's findings like this that highlight that the switch over will probably be much faster than almost anyone (besides myself) today is predicting.