Wednesday, September 16, 2026 79° Today’s Paper
By Rob Kay
Today
COURTESY PHOTO
Olin Kealoha Lagon
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I don’t have to remind readers how nasty Lala was to Hawaii residents. Food spoiled, the internet disappeared, traffic signals went dark and medical devices became inoperable. Should homeowners be thinking more seriously about backup power?
For some expert advice, I called my old friend Olin Kealoha Lagon.
A serial social entrepreneur and technology whiz, Lagon founded high-tech firms including Shifted Energy, a renewable-energy company, and ChipIn, the first crowdfunding platform, as well as social ventures such as Purple Mai‘a.
I sat down with him recently to discuss the ins and outs of adding battery backup to a home solar system.
Question: Do you believe the power outages have exposed the vulnerability of Oahu’s electrical grid?
Answer: Full disclosure. I helped invent technology that balances grids across the U.S. and Canada, including here, so I know this problem well. Our grid is unique and fragile. Each island runs its own standalone grid. On the continent, operators can buy power from neighboring regions when they run short. We can’t even do that among our islands.
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In 2015, Hawaii pioneered a 100% renewable electricity mandate. Since then, an explosion of solar has created more generating capacity on customer rooftops than any single power plant in the state. Providing reliable electricity with more than 120,000 rooftop generators that nature controls is insanely hard engineering.
Lala showed us how fragile this is, but also the resilience of our crews, who restored power to nearly all of Oahu days ahead of schedule. But some of that resilience needs to live in our own homes.
Q: Given the recent storms and lengthy power outages, a battery is starting to look like a pretty good insurance policy. If you already have (Net Energy Metering) solar and can afford it, does it make sense to add a NEM Plus system with battery backup?
A: Lucky you if you have NEM. Adding NEM Plus with battery backup makes a lot of sense. You keep your original NEM system while adding generating capacity and, importantly, electricity when the grid goes down.
Grid-tied panels normally shut off during outages to protect line workers, so ask whether your legacy panels can be wired into the new backup circuit. It’s possible but adds cost, design and approvals.
Q: What would a typical NEM Plus battery system cost, ballpark?
A: Roughish: If you use about 1,000 (kilowatt-hours) a month — about $450 — you’ll need a 10-(kilowatt) system with a battery, about ($45,000) installed. The federal credit is gone. The state credit is 35%, capped at ($5,000) per system, although tax rules can treat a 10-kW installation as two systems. A new state law adds income limits and a statewide cap starting in 2027.
Enroll the battery in HECO’s BYOD Plus and get about $2,000 upfront plus roughly $50 a month in export credits. Your final cost could be about $33,000, with the system paying for itself in about seven years. After that, it generates “free” electricity for 15 years or longer. But check with your tax person.
Q: How much battery do you really need?
A: The most popular home battery holds 13.5 kWh. A fridge uses about 2 kWh a day, so one battery easily runs a fridge, internet, lights, fans, microwave and CPAP. It won’t carry big loads like some water heaters, dryers and AC.
With enough sun, your panels can recharge the battery the next day. But your electrical panel isn’t smart enough to exclude large loads during an outage. Know which breakers feed them and flip them off, or they’ll drain or overload the battery.
Q: Could a portable unit keep an apartment dweller going?
A: For essentials, it would be expensive. A battery big enough to run a fridge costs about $2,500 and weighs 50 pounds or more. Apartment-sized solar panels probably won’t keep a fridge going for multiple days. You may still need a small generator run outdoors a couple of hours a day.
Q: Can we do (photovoltaic) balcony systems like Germany?
A: These are panels you buy at a German hardware store and plug into an outlet. Germany has more than 1.3 million Balkonkraftwerke (“balcony power plants”) safely operating. Utah passed the first U.S. plug-in solar law last year and at least seven states have followed.
Our two bills died last session, even though one passed the Senate 25-0 before stalling in the House. About half our homes might not be ideal for rooftop solar, so this could be a huge equalizer. I really hope we pass it here.
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Rob Kay, a Honolulu-based writer, covers technology, health and sustainability. He is the creator of Fijiguide. com and can be reached at Robertfredkay@gmail.com.
Rob Kay, a Honolulu-based writer, covers technology, health and sustainability. He is the creator of Fijiguide.com and can be reached at Robertfredkay@gmail.com.
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