Hawaii island’s solar industry took a big hit in 2016.

The number of permits issued on the Big Island dropped 56 percent compared with the year earlier. In 2016 there were 1,256 permits for solar electric systems, according to data compiled by Marco Mangelsdorf, who tracks rooftop solar permits and is president of Hilo-based ProVision Solar. There were 2,833 permits in 2015.

Earlier this week, Mangelsdorf provided data showing Maui County also saw a substantial decrease. The number of rooftop solar permits issued for Maui, Molokai and Lanai dropped 47 percent in 2016 compared with the year earlier. Some 1,657 permits were issued in 2016, compared with 3,153 in 2015.

“Of all Hawaii’s four counties, the Big Island’s PV industry suffered the biggest hit in 2016,” he said.

A similar drop in numbers on Oahu and Kauai is likely to be seen once their numbers are released. The number of permits issued has been shrinking since the state ended a popular solar energy incentive program called net energy metering in 2015.

The only program still available for Hawaii residents to add rooftop solar and stay connected to the electric grid is self-supply, which prohibits solar owners from sending excess energy onto Hawaiian Electric Co.’s grid but allows owners to draw from the grid. Most systems need batteries to meet self-supply requirements.

“As with the other islands served by Hawaiian Electric utilities, PV companies and those homeowners still wanting to go solar PV were hit hard with the elimination of net energy metering in October 2015, the limited (grid-supply program) cap which was reached last summer and the painfully slow adoption of (self-supply program) systems,” Mangelsdorf said.

The grid-supply program, the other program state regulators used to replace NEM, credited customers for a reduced amount of money compared with NEM for the excess energy they sent to the grid. All of the islands hit the state’s limit within a year of the grid-supply program launching. Regulators have offered to allow more to apply for grid-supply, if residents who did not end up installing a solar system under NEM are removed from a list of accepted applicants.

“For some of us in the industry being able to install more (grid-supply) projects will provide us at least something of a lifeline as we wait for (self-supply) sales to ramp up,” Mangelsdorf said.