I don't live in Hawaii anymore, but when I last did and HELCO was still allowing homeowners to participate their home solar with a grid tie they had the following limitations: no matter what your balance of power production to consumption differential was, there was no discount for a base 'connection fee' - essentially the lease of the meter.

They would sell each household kWh at full price, and 'purchases' daytime production at a wholesale rate derived from a mainland commercial grid interconnect rate, the difference was about one order of magnitude, and their meter had the ability to cap output from the panels, such that no matter what the purchase price of excess power would never exceed the consumed power price, and every month there was at least $80ish in connection fee.

This kept most of my neighbors from either, a) considering solar for the household, or b) deciding to stay disconnected from the grid when the house finished installation.

My friends with new houses being built mauka (up-country) also faced a Many-KiloUSD per pole cost to run lines along the road to new housing areas, and if even you could get everyone on a road to pitch in for a new run it often was more economical for everyone to just DIY their own selection of solar, wind, generator, batteries and it still was less expensive than just running the lines, even before accounting for kWh costs.

Even in towns down closer to the coast, it still made more economic sense to use wind+solar and a batteries with a backup generator than to pay for HELCO's power... which also came in with such erratic voltage and irregular wave profiles that it routinely toasted anything sensitive, from refrigerators, televisions, washing machines, you name it... which careful reading of the manufacturer warranties shows that for most main brands they specifically exclude Hawaii from any guarantee of service or replacement.

Now, HECO services a different island than where I lived, and the situation is widely variable in each of the islands, with completely different rules and operating practices. So that's not to say my observations have any validity outside of Big Island, and some limited observation from friends' ohana in Maui.

When we lived in town, it was necessary to put UPS inline for everything more complicated than a toaster oven, and when we moved way up mauka to our little goat farm, the answer was solar and at first golf cart batteries, then a whole stack of recycled/reconditioned submarine iron core 1.2v cells and some very heavy duty cycle inverters; combined with extremely conservative electricity consumption: about 10~15 kWh per week.

One of the benefits of using all LED red lighting at night, and living at elevation to never need A/C, plus methane digester powered by goat waste for refrigeration and mostly using a rocket stove for cooking with guava wood. and no TV, no tower PC, hand crank wringer for laundry like most mainland peoples great-grandparents and line dry on the patio where the rain cant soak them and the wind might get them dry before too long. Its not an easy or soft way to live, but in many ways my wife and I wish we sere still there.