Why UH Hilo should install its own microgrid for power
The Big Island runs on its own electric grid, as all of our islands do. We’re not plugged into anyone else — no undersea cable to O‘ahu, no mainland interconnection to fall back on when something goes wrong. That independence is part of what makes this island special, but it comes with a price tag.
Electricity here costs around 48 cents a kilowatt-hour all-in, by far the highest in the country, and when a storm or a lava flow or a single downed line takes out the grid, there’s no neighbor island to borrow power from.
So when I look at the University of Hawai‘i at Hilo — a whole campus of buildings, labs, dorms, and wide-open rooftops sitting right in the middle of all this — I see one of the most obvious candidates on the island for a self-sufficient microgrid.
UH Hilo should be able to run on its own power when it needs to, with a combination of solar, battery storage and back-up generator, while staying connected to the HECO grid the rest of the time. Here’s why I think it’s worth doing, and what it would actually take.
UH Hilo already started — and then got left behind
This isn’t a from-scratch idea. UH Hilo already has roughly 500 kilowatts of rooftop solar spread across the campus — on the library, the business school, the performing arts center, and more — saving the university about $300,000 a year on its power bills. It even has a battery storage pilot tucked behind the Sciences and Technology building.
That’s a real head start. But here’s the frustrating part: when the University of Hawai‘i built out its big coordinated solar-plus-storage system — the one that lets Maui College and four O‘ahu community colleges run on the sun — UH Hilo wasn’t included.
Our island campus, sitting on the most isolated and most expensive grid in the state, got the piecemeal version: a few arrays here and there and one small battery, rather than a system designed to actually carry the full load of the campus. That’s exactly the gap I’d like to see closed.
Hilo’s weather is the catch — but not the dealbreaker
I won’t pretend the sun cooperates here the way it does in Kona or Honolulu. Hilo is pretty rainy and it shows up in the numbers. Based on what that existing 500 kW array actually saves, I estimate it’s running at a capacity factor of only about 14–16% — strikingly low compared to a sunny leeward site (which can be over 25%). In plain terms: each solar panel in Hilo produces a lot less than the same panel would in Waikoloa or Kona.
That single fact drives the whole design. In Hilo, going islandable is storage-heavy — you can’t just bolt on panels and call it a day. You need enough battery to get through the night and a cloudy stretch, and you need a backup generator (running on biodiesel, ideally) for the multi-day storms when neither sun nor grid is available.
But there’s good news that often gets overlooked, and it changed my own thinking when I worked through these ideas. Modern bifacial solar panels — which capture light on both faces — paired with white, high-reflectivity “cool” roofs can squeeze a lot more energy out of the same roof space. Over a white roof, field measurements show bifacial panels gaining 20% or more, and elevated installations over bright surfaces can reach 30%.
And contrary to what you’d assume, this works even in cloudy Hilo: white surfaces bounce diffuse light efficiently, so the percentage gain mostly holds even when the sky is gray. Done right, that could lift the effective capacity factor of new arrays from around 15% toward 18–19%. It doesn’t make the storage problem disappear, but it makes the solar side of the equation meaningfully better — and it stretches every square foot of roof we have.
What “islandable but still grid-connected” actually means
I want to be precise here, because this is where people sometimes get the wrong idea. I’m not arguing UH Hilo should cut the cord and leave the grid entirely. If big institutions all defect from the grid, the fixed costs of the poles and wires get dumped onto everyone left behind — that’s not fair, and it’s not the goal.
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What I’m describing is a campus that runs grid-tied as usual, but can disconnect cleanly and power itself when the grid goes down, then reconnect when it comes back. To do that, UH Hilo would need a handful of things it mostly doesn’t have yet: oversized solar on rooftops and parking canopies, a much bigger battery, a biodiesel backup generator for long outages, the control equipment that lets a campus safely “island” itself, and a plan for which buildings stay powered first when the grid is down.
Two ways to get there
There’s an affordable version and an ambitious version of this microgrid idea, and I think we should pursue both — starting with the first.
The near-term, cost-effective step is a critical-loads-only microgrid: keep the campus essentials running indefinitely during an outage — emergency operations, labs, server rooms, security, refrigeration, some housing — while less critical loads power down. This is the natural next step from what UH Hilo has already built, and it’s the kind of resilience investment that pays for itself the first time a hurricane parks offshore.
The bigger vision is a full-campus islandable system that runs the whole campus on renewables day to day and can ride out extended storms. Here’s the honest math, and it depends mainly on one thing: parking lots. The campus rooftops can hold maybe 2.5 megawatts of solar — only about a third of what the campus uses in a year, given Hilo’s weak sun. To get the rest, you have to build solar over the parking lots. Cover enough of them with bifacial panels over white, reflective surfaces and you can reach roughly 7 megawatts — enough, on paper, to match the campus’s entire annual electricity use. So carports aren’t a nice extra here; they’re the whole ballgame, the difference between a half-solar campus and a net-zero one. Even then it’s tight, and batteries, a biodiesel backup, and the grid still cover the nights and the multi-day storms.
But the headline is encouraging: with rooftops and parking lots working together, a net-zero, self-powered UH Hilo is possible. It’s not clear that going for this full version of the microgrid would make sense financially since it does rely so much on parking lots, and parking lot solar is substantially more expensive than rooftop solar (though of course, there are other benefits from carport solar such as car shading) when the HECO grid is headed for 100% renewables in the 2030–2035 timeframe under current trajectories.
The critical loads version of a microgrid still makes a lot of sense due to possible grid outages and cost savings.
It’s already the law — and it’s a state job
Here’s something a lot of people don’t realize: the University of Hawai‘i is legally required to get to net-zero energy across all its campuses by 2035. That’s state law, passed way back in 2015. UH is the second-largest electricity user in the entire state, and as of early this year it had reached only about 20% of that goal. The clock is ticking, and Hilo is one of the campuses furthest behind.
This matters for how I think about my own role when I win my race for state House. UH is a state institution, so this is squarely a state legislative issue — no county tangles, no jurisdictional confusion. I’m not going to pretend a single freshman representative can snap his fingers and fund this. What a legislator can do is real and concrete: champion the capital appropriation for it, push it into the UH budget request, use budget hearings to ask why Hilo got left out and how we fix that, support legislation that accelerates the 2035 deadline, and bring UH, HECO, and microgrid developers to the same table. My philosophy is to empower, not dictate — and this is a place where a little legislative push could unlock a lot.
Nobody has to write a giant check up front
The objection I expect is “great idea, but who pays for it?” The encouraging answer is that UH doesn’t have to fund this out of its own capital budget. The same model that built the other five campuses’ systems works here: a private developer finances, owns, and operates the equipment, and UH simply buys the power at a rate below the HECO tariff. Layer in federal resilience grants — FEMA and Department of Energy money exists precisely for this — and use state capital funds only to close whatever gap remains. The financing path is well-worn.
This is bigger than a power bill
Yes, a microgrid would save UH Hilo money on electricity, but the real prize is resilience. When the next big storm knocks out the grid possibly for days, a self-powered campus becomes a community anchor — a place with lights, refrigeration, internet, and shelter when people need it most. It would also make UH Hilo a working model for the rest of the island: proof that an institution on an isolated, expensive grid can take real control of its own energy.
That’s exactly the kind of energy independence I want to see more of on this island — practical, locally rooted, and built to keep the lights on when it counts. UH Hilo is the perfect place to start. Let’s get it done.
A more detailed policy brief behind this post — including the sizing tiers, cost ranges, and verification items — is available on request.
