The number of solar-energy system permits issued by the City and County of Honolulu increased by 45 percent in January from the year-earlier period.

In January the city’s Department of Planning and Permitting issued 407 permits for photovoltaic systems, up from 280 issued in January 2015, according to data from Marco Mangelsdorf, who tracks rooftop-solar permits and is president of Hilo-based ProVision Solar.

While the number of permits is up from the year before, January’s numbers dropped 45 percent from December.

“There’s typically a drop-off in PV permit numbers in January compared to (the fourth-quarter) months,” Mangelsdorf said.

The state Public Utilities Commission ended a popular solar incentive program called net energy metering (NEM) in October. The program credited solar owners the full retail rate for the excess energy their systems sent to the grid. When it ended NEM, the PUC replaced it with two less attractive options.

“We may also be seeing the beginning of the decline of new post-NEM sales,” Mangelsdorf said.

The programs replacing NEM are called “customer grid supply” and “customer self-supply.” Customers who use grid supply are credited approximately 15 cents per kilowatt-hour for the excess energy their systems send to the grid instead of the full retail rate.

Grid supply has a minimum charge of $25 a month, while NEM had a minimum of $17.

Under the self-supply program, solar customers do not export energy to the grid. Batteries linked to PV systems store the excess energy produced.

The PUC ordered Hawaiian Electric Co. to make a decision on self-supply systems under an expedited review.

One self-supply application has been approved by HECO. No grid-supply application has been approved.

A number of grid-supply applications have been rejected by HECO due to problems with the applications, HECO said. There were 96 grid-supply applicants waiting for approval as of Jan. 26, down from 282 applicants in late December.

“The number of customer grid-supply applications are alarmingly low compared to the frenetic volume of submitted NEM applications from January-October 2015,” Mangelsdorf said. “If — and this is the big if — these numbers were to keep up over time, the local PV industry will face a very steep decline.”