Inside the first fully dispatchable utility solar-storage project in Hawaii
Combining solar power and storage may make sense in Hawaii, but does it on the mainland?
Hawaii has frequently been cited as a laboratory for renewable energy and these days the same can be said for storage on the island state.
Last month SolarCity announced plans for what it says is the first fully-disptachable solar-plus-storage project on Kaua’i, the fourth largest of the Hawaiian Islands.
“We’re really excited about [this project] 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,” Bob Rudd, SolarCity’s director of energy storage project development, told the audience at a recent storage conference.
The nation’s leading residential installer is building the project near Lihu’e on Kaua’i’s southeast corner. The project includes a 13 MW photovoltaic solar array, but is unique in that it includes its own solution to the intermittency problem that solar power faces.
The power generated by the PV cells will be used solely to charge a 13 MW battery array capable of providing 52 MWh to customers of Kauai Island Utility Cooperative (KIUC), the island’s sole electricity provider. That means the solar cells will charge the batteries during the height of the day, and the batteries will discharge the stored power to customers during the evening peak between 5 p.m. and 10 p.m.
“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,” Rudd said. “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.”
SolarCity has yet to say what kind of batteries it will use on the project or who will manufacture them, but there has been some talk in the industry that Tesla is on the short list of suppliers. That would make sense, as SolarCity Chair Elon Musk is also the CEO of Tesla.