One of the continent's largest energy storage shows hit San Diego, Calif. last week to good crowds and an increased momentum in the market. I emceed for a number of presenters in this year's Storage in Action series, seeking to highlight actual working energy-storage projects out in the world -- not pilots, but real, value-creating energy-storage projects.  Part 1 looked at S&C Electric Company, JuiceBox Energy and NRSTor. Here's what SolarCity had to say.

Bob Rudd, SolarCity's director of energy-storage project development, focused on the company's behind-the-meter business. He said the energy storage group's core service is "adding a battery to a PV system, financing a package, and ultimately saving the customer money on both energy charges and demand charges. The moral of the story is we're shifting energy to when it's needed most."

Rudd gave an example of a smaller commercial SolarCity customer in the Southern California Edison utility territory. Referring to the chart shown below, he said, "You can see at the bottom here, basically January through December, and then from midnight to midnight. This is what their load profile looks like before we show up. You can see the peaks and the red zones where they're being charged substantial money for their demand charges."

"Then after we come in, it looks more like this [chart shown below]. As you can see, those peaks have now become plateaus, and the red areas where they were previously paying exorbitant fees for the demand charges are now dramatically reduced. This is what I call more of a commercial customer. As you can see, their peak load is really in this example, no more than 200 [kilowatts]. Beforehand, it was up to 300 [kilowatts]. This represents a pretty broad swath, a broad spectrum of the market that we're pretty active in, with a number of different retail sites and other customers."

Rudd also provided an example of an industrial customer. "You can see the load profile here is 4.5 megawatts at its peak, and also extremely erratic. This is a site where they do a whole lot of processing, a lot of R&D and different things, and so it just jumps all over the place."

"As you can see, a lot of those peaks are now plateaus, and they've dropped pretty significantly again here. I'd love to be able to share some of the customer names here because they're pretty well known, but we aren't exactly allowed to talk about it," Rudd said.

"Last but not least, I was going to talk a little bit about a project that we recently announced in Kauai, which we're really excited about because it's effectively, as far as we know, the first utility-scale solar-plus-storage project done on a purely commercial basis that is affecting the shift of the vast portion of PV production to the nighttime peak. Anyone that's been out to Kauai will notice that they have a lot of solar on the island and really don't have any appetite at all for solar at midday. If anything, they were already in a bit of a curtailment state during certain days. So, they love solar, they want more because it's cheaper than what they otherwise would realize, but they don't need it during the day. So what we've done here is taken a 13-megawatt-AC PV system, and coupled it with a 13-megawatt/52-megawatt-hour battery bank, and effectively least the vast majority of that midday solar production to the evening hours when they have their true peak event on the island, where they're spending all their units at somewhat inefficient heat rates."

Rudd concluded, "This is a project we're focusing on right now with a signed contract" and working through permitting and PUC rules. "We're intending to COD in Q3 or Q4 of next year. It's pretty exciting because... it really proves the concept of firm, dispatchable solar power at scale, without grants, without any economic influence other than just a purely commercial transaction. So this project is something we're really excited about."