As rain from Tropical Storm Lane subsided Monday, Hawaii’s solar industry seems to have avoided serious damage.
However, two solar industry professionals called the situation "a wake-up call."
Though Lane weakened as it slammed into Hawaii, 13,000 Hawaiian Electric (HECO) customers lost power from the storm. According to the National Weather Service, Lane caused the third-highest rainfall from a tropical cyclone since 1950 in the U.S. The storm washed away roads and damaged houses and buildings.
The impact was serious, but earlier reports suggested Lane could have wrought much more devastation. Is Hawaii's distributed energy industry ready for even stronger storms?
“It’s a matter of time before we do get hit by that monster hurricane,” said Will Giese, executive director of the Hawaii Solar Energy Association. “It’s much better to treat things pre-emptively rather than…when you start experiencing symptoms.”
Giese said he sent out an email to the organization’s membership in the middle of last week providing guidance on how to cope with a potential influx of customer inquiries regarding system issues. On Monday morning, he hadn't heard from installers or developers regarding problems.
“That leads me to believe that there wasn’t a huge impact on residential and commercial solar,” he said. Later in the day, still no major electrical or solar system damage had been reported.
Colin Yost, chief operating officer of Honolulu-based solar provider RevoluSun, said aside from some “horrific” flooding in parts of the state, the solar industry was “breathing a collective sigh of relief.”
The flooding didn’t have much impact on solar, according to Yost, because winds were not strong enough to destroy systems that can withstand winds at 105 miles per hour, as required by building codes. The biggest threat, Yost said, faces Hawaii’s older housing stock, where full roofs could fly off with panels still attached.
HECO said on Monday the utility had restored all customers with storm-related power outages, and a spokesperson said there had been no news of damage to grid-scale solar systems.
Ahead of Lane’s arrival, Yost said RevoluSun fielded numerous requests from customers to test their storage systems. Out of approximately 7,000 RevoluSun residential solar customers, only several hundred have battery storage as well. But that’s changing. Looking ahead, the company plans to add energy storage, which it started deploying in 2017, to all installations.
After the storm, Yost said RevoluSun saw an “enormous increase” in storage inquiries. Although between 16 and 20 percent of HECO, Maui Electric Company and Hawaii Electric Light Company customers have rooftop solar, most installations in Hawaii are not currently supported with backup batteries.
“It’s very sad to have this big solar system on your house that’s capable of powering your whole house indefinitely, and it just doesn’t work if the grid goes down,” said Yost. “I think you’ll likely see an explosion of storage installations in Hawaii over the next couple years. It just makes a lot of sense.”
Yost said a general spike in interest, as well as tariff changes that favor battery storage, are contributing to the rise in solar-plus-storage. On Oahu, Hawaii’s most populous island, customers now get about 15 cents per kilowatt-hour for “smart exports” outside daylight hours and about 10 cents per kilowatt-hour for “customer grid-supply plus” power exported during the day. The 2017 average retail rate of electricity was just over 28 cents per kilowatt-hour, making storing solar power more economical.
For RevoluSun’s customers who have Tesla Powerwalls installed, Yost said a new feature called “Storm Watch” — which, when triggered, prioritizes charging the system to 100 percent backup power before a weather event begins — provided important support.
According to Tesla, that feature was rolled out in July as part of a software update. The company, which has been embroiled in controversy this summer, declined to specify the regions where it’s currently available or the types of weather events it supports aside from hurricanes.
Tools like Storm Watch could be helpful during extreme weather events when customers have less time to react than they did with Lane, according to Yost. But he said Hawaii, often viewed as a leader in clean energy, has much to accomplish in terms of resiliency.
Crude oil was Hawaii’s top import in 2017. And much like with Hurricane Maria in Puerto Rico, Lane-related service disruptions were caused by problems with transmission and distribution rather than generation, according to HECO. Hawaii’s transmission system also crosses rugged terrain. In the wake of Lane, the utility said it's rerouting service to redundant lines while repairing damage.
Both Yost and Giese suggested some progress is being made, mentioning recent grid-hardening initiatives from Hawaii’s Public Utilities Commission. In July, the PUC opened a docket on establishing a microgrid tariff that referenced Puerto Rico. In June, the PUC asked state utilities to accelerate interconnection of rooftop solar, storage projects and the development of large-scale renewables in response to volcanic eruptions that closed down the Puna geothermal plant.
To continue pushing resiliency efforts forward, Giese also said he hopes state lawmakers will consider legislation similar to several bills that ultimately stalled this year, which focused on grid resiliency planning.
“Obviously, this is on the state’s mind,” said Giese, but, he added, “faster would be better.”
On Monday, another tropical storm — Miriam — was gathering force in the Pacific.