‘Self-supply’ solar delayed by inexperience

The increasing interest in Hawaii’s third-string solar program is caught on a snag as the city, the utility and solar contractors learn more about battery technology.

Hawaiian Electric Co. has seen nearly 350 applications for “self-supply” rooftop systems — the only solar program currently authorized in its territories, according to a weekly report released by the utility Tuesday. But only two have flipped the switch.

Ron Hooson, founder of Solar Inspectors Hawaii, said the low number of energized systems is due to contractors and city and HECO plan reviewers having to cut their teeth on how to monitor and inspect the batteries that will connect to the solar energy systems.

“There are a myriad of questions that haven’t been asked before they had batteries associated with them. … It’s a new technology and everyone is being extra cautious or thorough,” Hooson said. “There is teething on both sides.”

Most self-supply systems include a battery to store power during daylight and to use at night or in cloudy conditions. This is because the program prohibits owners from sending excess solar to the grid for credit, but allows residents to draw power from the grid.

Self-supply was one of two programs that replaced the popular “net energy metering” solar program that paid residents the full retail rate for excess electricity sent into the grid in October 2015. But that program and another watered-down version of it, known as grid supply, are no longer available.

Due to the added technology and lower incentives associated with the program, the “self-supply” option saw a slow start.

IN JUNE, the first self-supply system was officially energized. The second was energized in August.

Anthony Aalto, owner of the first self-supply system in Hawaii and chairman of the Sierra Club Oahu, said he expected the process to be slow because of the new technology involved. Aalto was the first to install a Tesla Motors Powerwall battery in Hawaii.

“I entered into this whole thing knowing I would be a guinea pig,” Aalto said. The city Department of Planning and Permitting and HECO “were very careful and cautious,” he added.

Aalto said the initial delay for his system came from the DPP with the permit application going through three sets of comments. The DPP’s returned paperwork included questions, such as what liquid was inside the battery.

“It was a slog,” Aalto said. “I don’t blame DPP or HECO for that matter. They are dealing with safety issues and their concerns I think are genuine. … I am putting a giant lithium-ion battery on the wall of my house.”

After the permits were approved Aalto’s system was turned on briefly in May — only to face an additional month of delay due to his system still sending excess energy to the grid. “There was a small amount of leakage of electricity into the grid,” he said.

HECO spokesman Darren Pai said that the utility wanted to be confident that the systems are going to do what they are supposed to according to the PUC’s requirements. “For some of the first systems we did some work with the solar companies,” he said. “We went out to take measurements and collected the data to make sure the systems were operating as they are intended to do and met the program requirements.”

The length of the review process at HECO has fluctuated over the year, as the review on Oahu was as short as one month in August and more than 76 days in October.

“It did take some time with these first systems,” Pai said. “The hope is that you can get these systems out there and customers can receive the benefit in the choices and investments that they are making.” As the city and HECO work to understand the new technology, the battery industry changes at a quicker pace. The second Tesla Powerwall was announced in October.

Hooson, the Solar Inspectors Hawaii founder, said the delay will help streamline the process for batteries, but that right now it’s a “pain in the neck” for the solar industry.