Customers of the Hawaiian Electric Companies installed solar photovoltaic systems with 129 megawatts of generating capacity in 2013, up 39 percent from the previous year, the utility reported today.

That was a significantly slower pace than in 2012 and 2011 when PV installations more than doubled each year.

There were 17,609 PV systems installed last year across the utility’s service area, which covers Oahu, Maui County and Hawaii island.

The cumulative amount of PV installed through 2013 totaled 300 megawatts of generating capacity.

According to HECO 10 percent of its customers on Oahu have PV systems, by far the highest percentage of any utility across the country. In Maui County the figure is 8 percent, and on Hawaii island it is 7 percent, according to HECO.