IIRC, that's because of the silly way (given Hawaii's abundant solar and geothermal resources) in which most electricity is generated in Hawaii: burning imported fossil fuels. If the local renewables were fully exploited, I can't think of a reason for costs to be so high.
The island layout doesn't help either. The geothermal resources are all on the Big Island, and that's also where it would be easier to install large-scale solar facilities. But the main energy usage is on Oahu, and there isn't an inter-island power grid.
You're right! Hawaii's utility is fighting against solar installations, and I see Tesla's energy solution coming in to push the uptake of solar installs in Hawaii.
You don't have to wait on the utility for their approval if you're not connected to them.
