Hawaiian Electric Co. estimates that it will be opening up 50 to 70 percent more room on a typical circuit for photovoltaic systems and reducing the number of costly interconnection studies on Maui by "changing to a different kind of standard," said a HECO official Tuesday.
The interconnection study, which can cost thousands, has been a sticking point as the output of PV systems on Maui and across the state has doubled annually since 2008 to a projected 160 megawatts statewide by year's end.
Peter Rosegg, spokesman for Hawaiian Electric Co., explained that the old threshold for triggering an interconnection study had been more than 15 percent of peak, or 50 percent of the daily minimum load of PV on a circuit.
Haleakala Solar installer Andy Kala fits a solar panel into place on the roof of a Kahului home on Wednesday morning. Electric utilities have changed the standard for the amount of photovoltaic systems allowed on typical island circuits, meaning there will be more opportunities for residents to get solar power.
The Maui News / MATTHEW THAYER photo
The new "checkpoint" for typical residential systems before a possible interconnection study, which he said could range from $500 to $4,000, is now 75 percent of the minimum daytime electrical total for PV.
"That will create more room on the circuit," he said.
Given differing circuit sizes, Rosegg could not quantify exactly how many more PV systems could be added with the new checkpoint. He said there would be "50 to 70 percent more room on a typical circuit" on Maui.
"It's a substantial addition," he added.
"The change should make the move to PV for many customers simpler and faster," said Colton Ching, HECO vice president for system operation and planning, in a news release.
"Operating experience with some of the highest PV penetration in the nation on our companies' grid has made this new approach possible," Ching said. "This experience, coupled with technical studies conducted with other experts, gives us confidence that we can make this change and still ensure reliable service for our customers."
Adding PV while maintaining the stability of the system for all customers is the goal of HECO, Rosegg explained.
"We're the ones responsible for keeping the lights on," he said.
The problem with integrating PV into a circuit is that there is no way of know how much electricity the solar systems will feed into the circuit, Rosegg said. Up to a certain point there is no problem.
After that point, HECO has been requiring interconnection studies to determine whether devices need to be added to keep the circuit stable, he explained.
As of Oct. 1, most residential and some commercial customers of HECO, Maui Electric Co. and Hawaiian Electric Light Co. on the Big Island can install single-phase PV systems up to 10 kilowatts, a typical residential system, on single-phase transformers and participate in Net Energy Metering (NEM) - with no interconnection study.
HECO also said that any customer who previously paid for an interconnection study and system upgrades to install a 10-kilowatt or smaller single-phase PV system will be refunded the cost of the study and any upgrades.
On Maui, that involves a "handful" of customers, said Rosegg.
"This is a step in the right direction, and the timing could not be better," said Brad
Albert, co-owner of Rising Sun Solar on Maui and founder of the Hawaii PV Coalition. "We enjoy a very good working relationship with the utilities and appreciate their continued support for renewable energy. This shows they are listening to the concerns of their customers and the solar industry."
HECO noted that a customer or contractor still must provide the utility with a signed NEM application with all supporting paperwork before installing the PV system, and the county building permit must be closed before the NEM agreement can be finalized for the customer to begin receiving full credit for all excess renewable electricity sent to the grid.
On a few circuits, an interconnection study may still be needed to prevent service disruptions and for safety, the HECO news release said.
For larger NEM installations, the threshold for possible interconnection studies will remain at 15 percent of peak or 50 percent of the daily minimum load.
HECO has developed an online Solar Resource Center at goingsolar.heco.com with information on choosing a contractor, financing the installation and siting and sizing on a roof or property.
* Lee Imada can be reached at firstname.lastname@example.org.