California's Grid has overgeneration/curtailment problems too...

Check out this story at Breaking Energy.

in part:

Four times this past spring, the state’s grid operator had to shut off wind and solar power when it exceeded demand. The largest such curtailment was 1,100 megawatts during the morning of April 27, 2014.

Interesting, no?

That story comes from another source eenews.net and it is a pretty good report... down a bit there is this:

The plants that were curtailed likely received all of their contracted payments from the utilities, as contracts generally have a small curtailment provision built in. But as curtailment becomes more likely, contracts could become more flexible in the future, Bloom said.
"I think it means the contracts will allow for increased flexibility for dispatch by the utilities over time," he said. "There's a big change from the old days, when if you produced, they had to take it."
There will be a need to incorporate energy storage into renewables projects, as well. Right now, a solar project without storage would beat out one with storage solely on cost, even though utilities are under a new mandate as of last year to procure 1.3 gigawatts of storage by 2020.

The grid as free battery is on the way out as the importance of "when" grows. I've been wrapped up on Patent issues and missed the "Duck Curve" as a concept. Let's look into that shall we?

here is a "distributed generators fight back" read on the duck curve:

Solar supporters: Open season utilities duck on Ilsr.org:

"The duck is the perfect vehicle for utility complaints because it casts the growth of distributed solar as a major technical problem (an area where most policy makers defer to utilities) rather than an economic one, where utility complaints can be contrasted with their customer’s desires for more local control over their energy use and costs."

That 5 to 8 ramp is something else! It is certainly a call for west facing PV arrays... And some short-term storage too. What might many solar pre-chilling of HVAC condensers do to that picture? Could a daytime version of the Ice Bear eat the Utilities Duck? The Ice Energy people are used to marketing to utilities (smart) but the other side is also serviceable if you have surplus generation that would be curtailed during the day - better to shunt it to ice and then pull out that service during the peak charge time of 5 to 8...
"Short term storage, meet solar thermal, solar thermal, meet short term storage.