Newsletter: The battery knocking coal out of Hawaii

Part 2 of our newsletter series on Hawaii’s groundbreaking move to clean energy.

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For Hawaii to finally knock coal power off its grid, it’s going to need a bigger battery.

And now that’s happening. Developer Plus Power held a ground blessing last week for Kapolei Energy Storage (KES), which will be the biggest battery in Hawaii. It will take over duties from the AES coal plant that we haven’t seen large-scale batteries do before. (See my full story here.)

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Put simply, KES is a test case for how to switch from fossil fuels to clean energy without relying on gas power in a pinch.

Big fossil-fueled plants don’t just pump out electricity. They also maintain the frequency of the grid with the sheer inertia of their spinning turbines. 

  • If the grid drops out of the safe band of frequency, bad things happen.
  • Texas came disturbingly close to a systemwide collapse due to that very reason during its February 2021 winter storm.

Plus Power designed a battery that can respond to a dangerous shift in grid frequency faster than you can blink. It also has the ability to jump-start the grid network if it does go down due to a massive storm, tsunami, earthquake or what have you.

Technically, a battery in your house plays a similar role if the grid goes down: It forms its own islanded grid, maintains proper frequency and manages the flow of rooftop solar generation. But I’ve never heard of a battery performing these tasks in such a high-stakes situation:

  • Oahu is home to 1 million people and critical facilities like the U.S. military’s Indo-Pacific Command.
  • KES’ capacity equates to about 17 percent of the island’s peak demand, immediately making it a central component of ensuring the smooth operations of the grid.
  • By serving as a communal battery for the whole island, KES unlocks a bunch more solar development elsewhere, including on rooftops and community-scale projects.

Here’s how Plus Power’s lead developer Bob Rudd (formerly director of utility sales at Tesla) described the precedent at a ground-blessing ceremony last week:

Here, today, on Oahu, Plus Power and Hawaiian Electric are sending a postcard from the future. I’m certain that someday we’ll all look back, when there are dozens of projects just like KES on the mainland and all across the world, and we’ll think, We were there. Hawaii showed the world how to do it first.”
Kahu Kordell Kekoa presided over a traditional Hawaiian ground blessing last week, recognizing the past and future uses of the land.

This is another prime example of how batteries fundamentally change the nature of the grid in a cleaner and more efficient direction. Like the new battery I saw in Oxnard, California, which took the place of a proposed beachfront gas plant, what’s striking about Kapolei is how unobtrusive a crucial source of power can be when it’s made of batteries. 

  • KES will take up about 7 acres of previously disturbed land in the middle of an industrial park, meaning it’s far from any homes that could be disrupted by the construction. The Tesla Megapack batteries used at the facility are pretty quiet and don’t emit any fumes.
  • Its light footprint lets it slip into a place on the grid where a lot of electricity is consumed. 
  • That also lets Plus Power piggyback on the transmission lines built for earlier power plants, including the state’s final remaining coal plant, which is just down the road.
Kahu Kordell Kekoa presided over a traditional Hawaiian ground blessing last week, recognizing the past and future uses of the land.

By contrast, large solar projects need a lot more space, and that sometimes makes it difficult to get permits and garner community acceptance. 

A hot topic in Oahu energy circles right now is whether delays in clean energy projects will make the island temporarily more dependent on oil- and diesel-burning plants.

That could happen, but Oahu’s grid is certainly getting cleaner in the next few years. The deeper question is whether the island can pull off this shift from coal without any blips in grid reliability. That’s the other side of the Hawaii did it first” coin.

If Oahu succeeds, that means clean power plants can manage a grid operating without any neighbors to bail it out. That’s a high bar; the mainland grid is far more interconnected, so states can help out other states if needed (unless they choose to be an island, as Texas does). Proving the point in Hawaii expands the definition of what’s possible.

Read part 3 in the Hawaii newsletter series: How people can play a role in Hawaii’s shift to clean energy

(Lead photo: Ganapathy Kumar)

Julian Spector is an editor at Canary Media and reports on the rise of clean energy. He worked at Greentech Media for nearly five years, and before that he reported for CityLab at The Atlantic.