The federal Energy Information Administration estimates that 77% of Hawaii's power comes from burning fossil fuels, mostly oil and some coal. (source)
That would explain the high cost of electricity.
On Maui, we currently pay $.46/kWh AT HOME.
Unless one is grandfathered in, Maui Electric Company is happy to pay you zero for any solar power you send to the grid. There is an intermediate plan (for which we patiently waited) where they do pay you $.17 for solar power that you send to them—against the $.46 they charge when you want to buy from them.
Unless you join one of the new battery share programs, they also cap the amount of energy you are allowed to produce at 10 kWh. This really sucks as a normal house draw with the Tesla charger going to our Model 3 is around 12-13kwh (if we’re running any appliances on the house.) So even on a bright summer day midday, we need to reduce charge rate (usually from 48 volts to 36 volts) in order to pull only from our panels. (Typically, not a problem as we’ll pull from batteries and have plenty of light to top them off, but still…)
Needless to say, we have a solid solar generation system and two PowerWalls to which we’re adding a third. Hawaii does offer a 35% tax deduction up to 5K per year, (in addition to Fed Tax savings) so we’ve been slowly building up our system each year. Unfortunately, installed PowerWall price has doubled here, too…
Almost everything in Hawaii is expensive as we are a group of islands so most things are shipped here! That includes diesel for the electric utility. Even though we’re on track to be weaned off fossil fuels, there’s not enough nighttime backup yet for that to be practical. Hence the experimental battery sharing programs. But even though they do contribute to the upfront cost of your home’s batteries in these programs, the problem with them is threefold: (1) someone else is managing your batteries so you can’t practice the best battery management for longevity, possibly shortening the life of your expensive batteries (2) they are pulling power precisely when you are most likely to need it (3)they are still not offering to match the price of what they charge you to buy power from the grid to what they pay you for taking it from your system.
We do love the Tesla app’s ability to manage our Model 3, report on our solar system, and allow us to easily change charging rate to Model 3, battery backup reserve, remotely as conditions change at our house.
We also move our 2018 LR Model 3! And local (ranger) service is superb (although there has been little need for service so far!)
What we don’t love is:
(1) bait and switch of trade-in and new car prices (any other company, if terms are discussed and they take a deposit, that’s called “a contract.”
(2) Difficulty in talking to a real person about purchasing
(3) New policy of paying a second delivery fee to get a new car to an island other than Oahu (there are weekly boats going directly from San Diego to Maui, so not necessary to ship to Honolulu first)
(4) New policy that cats are shipped from Honolul to neighboring islands on an open carrier, so they arrive covered on salt and you must accept or reject befjre removing from shipping yard. Used to be you would meet at a golf course and inspect and accept your beautifully detailed new vehicle…
(4) loss of radar
Ah well—things are evolving. But not necessarily for the better…