Solar permits issued on Oahu began the new year by declining 25 percent to 172, marking the lowest number in January since Hilo-­based Pro­Vision Solar President Marco Mangelsdorf began tracking the data in 2012.

The drop-off follows a year in which permits issued for solar electrical systems on Oahu fell 4 percent and the number of state permits issued dropped 6 percent. There were 2,875 solar permits issued by the City and County of Honolulu in 2018, down from 2,993 in 2017 and far off the peak year of 16,715 in 2012. For the state, there were 4,830 permits issued last year compared with 5,151 in 2017 and down 77 percent from the all-time peak year of 21,385 in 2012.

Last month a record 78 percent of solar-permitted systems included batteries — with LG Chem and Tesla the most popular choices on Oahu.

“The Hawaii Legislature is, for the fourth consecutive year, considering a bill that would provide a tax credit for adding energy storage to existing renewable energy systems,” Mangelsdorf said. “Somewhat surprisingly, there’s not unanimity in the solar industry as to the value of seeing such a bill reach the governor’s desk.

“Creating a separate tax credit for adding batteries would likely be part of a broader bill which could also modify the current renewable energy tax credit provisions. Among some in the industry, there’s aversion to tinkering with those percentages lest they get ramped down over time. At present, there’s no sunset date on the Renewable Energy Technologies Investment Tax Credit.”

In other counties, Maui’s solar permits issued in 2018 fell 13 percent to 587 (the peak permit year was 3,153 in 2015), Kauai solar permits issued dropped 35 percent to 367 (the peak permit year was 876 in 2014) and Hawaii island solar permits issued rose 10 percent to 1,001 (the peak permit year was 2,883 in 2015).