The number of rooftop solar permits Hono-lulu issued in November fell by 50 percent from the prior year to mark 19 months of year-over-year decline for the solar industry.

Solar industry representatives are worried about sales as the winter months are usually a busier time of year for installations. 

The City and County of Hono-lulu issued 520 rooftop solar building permits last month compared with 1,040 in November 2013. Permits issued since the beginning of the year saw a drop of 51 percent with 5,914 issued through November compared with 12,163 in the same period last year, said Marco Man-gels-dorf, president of Hilo-based ProVision Solar.