Hawaii’s Solar Push Strains The Grid


January 20, 2015 | MIT Technology Review | Peter Failey

One of solar power’s biggest challenge is its intermittent nature: When you only generate electricity when the sun is shining, but people use electricity when it’s dark out, you need a way to store electricity for later. Hawaii is a real-world test case, putting centralized, grid-wide solar power to the test on a large scale armed with batteries. As MIT Technology Review reports, Hawaii has seen some major battery failures in the past couple of years. But that isn’t stopping them from pushing forward.

On the island of Kauai, solar is already the biggest contributor to the island’s power generation. Peter Failey writes for Technology Review:

That puts Kauai on the leading edge of solar power penetration, and [the Kauai Island Utility Cooperative] has bruises to show for it. Power fluctuations from a first large plant installed in 2012 have already largely burned out the big batteries installed to keep solar from destabilizing the island’s grid.

When clouds roll in, an energy storage system needs to be able to handle sudden drops in solar output. Failey does a great job of explaining the more technical aspects of this dynamic, like “frequency droops,” in clear language. Kauai’s original lead-acid battery system was designed to last for eight years, but is struggling after only two. So Kauai is installing a new grid-scale, lithium-ion battery system designed by French company SAFT that is better equipped to handle solar’s fluctuations.

Power grids across the country – the technology, the use patterns, the business models – are changing. Inside Energy will be following this issue closely in 2015, and in the meantime, here’s some related coverage from our archives: