The number of solar permits issued in Maui County plunged 23 percent during the first six months of the year.

There were 281 permits for solar electric systems compared with 363 in the year-earlier period, according to data compiled by Marco Mangelsdorf, who tracks rooftop solar permits and is president of Hilo-based ProVision Solar.

The downturn was a continuation of what occurred in the county in 2017 when solar permits plunged 59 percent from 2016 and 80 percent from 2015.

Through midyear the drop in PV permits for commercial projects declined 61 percent to 26 from 67.

“(That) was painful because these larger projects can be more lucrative than residential though often with a lower overall profit margin,” Mangelsdorf said.

The 23 percent drop in Maui County through six months was in contrast to increases of 45 percent on Hawaii island and 15 percent on Oahu over the same time period.

“One of the important differences between Maui County and the state’s other three counties is that the electrical department requires the submission of a MECO (Maui Electric Co.) conditional approval letter before issuing the required PV permit,” Mangelsdorf said. “Meaning, among other things, that PV permits pulled on Maui are more likely to lead to systems going live compared to the other islands. Some PV permit inflation is likely occurring on Oahu and the Big Island though an exact number of phantom permits cannot be easily determined.”

Mangelsdorf said another possible reason for the lower numbers for Maui is what he calls the Lanai and Molokai “contagion effect.”

“Practically speaking, the door has been all but closed for several years to the addition of more rooftop solar PV on those two islands due to the existing somewhat less than 2 megawatts on Lanai and Molokai’s 2+ MW of existing solar capacity and their effects on those islands’ grids,” he said.