A program to encourage Hawaii residents to install solar panels on their homes has once again hit a stumbling block because the state says it has reached its limit in approving permits.

That means residents can only get approval for solar panels if they also install self-storage batteries which will cost thousands of dollars more. The batteries can be installed on the walls inside or outside the house.

We wanted to know why there was a limit and if it’s even worth getting solar panels with the added cost.

Solar companies say having the limit is a bad idea and have already asked the Public Utilities Commission to raise it or, better yet, get rid of it.

Revolusun’s chief operating officer Colin Yost says most homes will need two of them with their PV panels. The cost of two batteries will be about $15,000 with installation.

“The result’s gonna be you’ll still save money over what you would pay to HECO, but you will not save as much at this moment as you would have saved under the Grid Supply program for most customers,” he said.

The Grid Supply Program is what PV customers have been participating in for nearly a year. They buy the solar panels and any extra energy is then sold to Hawaiian Electric. HECO says 2,900 customers participated in the program which started in October.

But the Public Utilities Commission set a limit that has now been reached. Commission chair Randy Iwase says the cap is necessary for the safety of the whole grid. “We have to be a little more conservative, because if something does go wrong, the whole grid is affected in an adverse way,” he said. “We could have blackouts and everything.”

Iwase says the PUC also has to reserve room on the grid for other forms of alternate energy, as well as give other families the opportunity to participate with what’s known as Community Based Renewables “to reach out to a segment of our population that cannot presently utilize PVs, either because of the cost or where they live if you’re a renter or if you’re in a condo.”

Yost says this goes against the state goal of relying on 100 percent renewable energy. Companies will have a hard time selling the self supply or self-storage systems because of the extra cost of the batteries.

According to Hawaiian Electric, only two of the self-supply systems have been installed statewide — 26 have been approved and an application comes in about once every week.

“They’re saying why is it that we’re getting less and less of an incentive to do this when we’re only at 20 percent,” said Yost. “We’re only at 20 percent on our way to a hundred percent. Why are we slowing everything down and I agree it doesn’t make any sense.”

No word yet on when the PUC will make a decision on lifting the limit that solar companies are asking for. They are also asking the PUC to add a time-of-day rate because energy used at night will be more expensive. That would be an incentive for customers to use the battery systems because they can store the energy during the day and use it at night.