A new rate scheme for Hawaiian Electric's rooftop solar customers is set to take effect this spring.
Some solar industry advocates say it could fundamentally change the local energy landscape.
"I think this is going to have a dramatic impact on our market," said Rocky Mould, president of the Hawaii Solar Energy Association.
He predicted that new rooftop solar grid interconnections could drop by 50% or more under the new tariff structure — which the Public Utilities Commission decided on last month.
Mould's primary concern is that it may become more cost-effective for new customers to use all the power they produce rather than sell it back to the grid.
"The order that came out is going to incentivize customers to build systems for their own use and not for export," Mould said. "There isn't going to be an economic incentive for customers to export to the grid."
About 37% of single-family homes served by Hawaiian Electric have rooftop solar panels, according to the utility's most recent sustainability report. On Oʻahu and in Maui County, customer-sited solar is the single largest renewable source of energy available to the grid. On Hawaiʻi Island, it ties with geothermal.
Mould said rooftop solar has played a critical role in providing clean power as fossil fuel generation phases out and utility-scale solar has struggled to come online.
He points to the Battery Bonus program, which was co-designed by solar industry experts, the utility, and the PUC.
The program incentivized households to build solar storage units that could provide energy back to the grid during high-demand hours.
It launched ahead of the closure of the AES coal plant in 2022 to help Oʻahu address its subsequent energy shortfall.
Mould said Battery Bonus showcased the power of rooftop solar to help "stabilize the grid, which in turn allows us to bring on more affordable, reliable, renewable energy as we approach 100% renewable energy and achieve the state's goals."
The Hawaii Solar Energy Association, along with the Hawaii PV Coalition, filed a motion asking the PUC to reconsider its decision on the new rates.
Earthjustice attorney Isaac Moriwake represents the association. He expects a response from the commissioners soon.
"It's a big question," Moriwake said, "if they're going to do enough to realize their mistake and correct course, or whether they're just going to follow through with this approach."
In a statement to HPR, a HECO spokesperson said they believe the motion filed by industry advocates has “not met the legal burden of demonstrating the PUC should reconsider its earlier decision.”
They further stated they anticipate the new structure will "streamline" the process for customers.
A response to the order from the Consumer Advocate, which represents the interests of utility consumers, is expected this week.
Moriwake believes this issue warrants a hearing and hopes the Commission takes action quickly.
"There is a looming deadline because the existing programs that are the lifeline for the solar industry are going to expire," Moriwake said. "We need some sort of roadway or pathway forward to keep the solar industry and the solar market going."
