HECO opens space for some 2,800 new solar systems to send excess power to grid

Hawaiian Electric said Wednesday the utility is opening up space for about 2,800 additional rooftop solar systems to connect to the grid.

More than half of that capacity is on Oahu.

The announcement comes after the state Public Utilities Commission ruled in March that the solar industry could bring on more customers for the previously full “grid-­supply” program, which credits customers for the energy their solar systems export into the grid.

Prior to the PUC announcement, the only solar program offered to homeowners by HECO was the “self-supply” program, which did not allow the owner to send excess power to the grid. Typically, the self-supply program involves an owner adding a battery system to hold excess energy generated by the solar panels.

The grid-supply program credits homeowners for excess power sent to the grid.

More space was made available for grid-supply systems because of homeowners who had previously been approved for a rooftop solar system but never installed one.

Jim Alberts, senior vice president of customer service at HECO, said the utility has space for at least 20 megawatts of added rooftop solar power, which equals about 2,800 systems depending on the size of solar systems owners connect to their homes.

If customers size their systems at 5 kilowatts, 4,000 systems would fill the 20-megawatt space, according to Alberts. The average system on Oahu is 7 kilowatts.

“If people size their systems right, according to their own needs, then we can probably have more out there,” he said. “There is no size limitation on a system today. If people want to put in a really big system, they can.”

“Hawaiian Electric advises grid-supply applicants to install a ‘right-sized’ system calculated for their household’s actual energy use rather than an oversized system designed mainly to sell electricity to the grid,” the company said in a news release. “Oversized systems cost more and can potentially export more electricity than the homeowner will receive credit for on their electric bill.”

Hawaiian Electric Industries is the parent company of Hawaiian Electric Co. on Oahu; Maui Electric, serving Maui County; and Hawaii Electric Light on Hawaii island.

There were approximately 400 grid-supply customers waiting in Hawaiian Electric territories for their solar systems to be approved as of April 4, according to the company’s latest weekly report.

After the grid-supply program originally hit its limit in 2016, new solar systems were prohibited from sending excess energy into the grid. This meant new solar customers were unable to earn credit for their systems and, in most cases, had to buy a battery system to prevent excess energy from exporting into the grid.

The solar industry has said the addition of grid-­supply systems will help the battery program get off of the ground, giving more time for battery prices to decrease and the solar companies to reach new customers.