Storage is cool.  It's so ingrained in our daily lives that it's invisible.  From the pantry closet and fridge storing our food to fuel tanks in our homes and cars, storage gives us the advantage to have something when we need it.  It's there waiting to be used.
So, doesn't it make a lot of sense to store excess power from photovoltaics and other distributed generation resources to provide backup during outages?  And, wouldn't storage change the intermittent nature of PV on cloudy days and at night into a more dispatchable resource? Couldn’t it also provide other grid services to help maintain power quality and reliability?
What's holding distributed storage back?  Why can't a home with a solar roof keep its lights on during the storm that puts the rest of the street in the dark?
To get a handle on some of the issues on the table, I tapped the expertise of two very smart colleagues, Chris Cook and Sky Stanfield.
Chris, who is on IREC's Board of Directors and (in full disclosure) the president and general counsel of Solar Grid Storage, says that "much like the debate that occurred with early solar incentive programs, the question once again arises with storage as to whether utilities should own those facilities."  The debate also continues on whether battery storage supporting solar should be co-located with distributed solar installations (at the customer site) or aggregated into larger community storage facilities that might be located at a utility substation.
Chris makes the point that if it is backup power that is the driver, a substation-based storage system does little in the way of providing backup power to the customer – storage at customer PV sites would be vastly preferable. "Contrast that with making solar PV dispatchable,” Chris explains. “If that is the desired outcome, then substation or even central storage is a fine solution and one doesn't have to address the added cost and complexity of customer-sited storage."
Sky, one of the lawyers who represents IREC, continued this thread at a recent Regulatory Advisory Board meeting by discussing that there are many types of storage technologies under development, and a variety of different locations in which storage can be deployed. "Where storage is deployed affects the types of functions it may serve and to whom those services are most directly provided,"  Sky said.