The first question, before price
New rooftop solar in Hawaii joins Smart Renewable Energy on one of two tracks. Export provides export bill credits, is open to all renewable technologies and has no project size limit. Non-Export allows all technologies and project sizes but does not permit export to the grid.
Which track applies is not purely a customer preference; it depends on what the grid at your location can accept, which is why it should be established early rather than assumed.
Ask your installer to confirm in writing which track your project is being designed for, and to say when that was confirmed rather than estimated. Hawaiian Electric provides a Customer Interconnection Tool, and an installer working Oahu regularly will use it as a matter of routine.
A quote produced before that question is settled is provisional whatever it says on it. Treat the answer as a precondition for comparing prices rather than as a detail to sort out later.
How a non-export design differs
On the Non-Export track, production that exceeds household demand at that moment has nowhere to go. It is consumed, stored, or curtailed, and curtailed production is simply lost.
That inverts the usual sizing logic. Instead of matching annual production to annual consumption, the design has to match production to consumption through the day, hour by hour, with storage bridging the gap between when the sun is up and when the household actually uses power.
The result is often a smaller array with a larger battery than a mainland homeowner would expect, and that is a rational design rather than an under-specified one.
Ask to see the daily profile behind the design: production, household consumption and battery state of charge on the same chart. Annual totals cannot show you whether a non-export system works, because the whole question is about timing.
Checking the savings model against the track
A savings model built for the Export track and applied to a Non-Export project will overstate results, because it credits production the tariff does not allow you to sell.
The check is direct. Ask what the model assumes happens to production that exceeds your consumption at a given moment, and listen for whether the answer involves a credit. On a Non-Export project it should not.
Ask also what curtailment the model assumes across a year. Some loss is expected in a non-export design and a model claiming none has not been built honestly.
If a battery is in the design, Bring Your Own Device Plus pays $400 per kW of committed battery capacity with no maximum cap, doubled for low and moderate income households, against a five-year commitment and a daily two-hour export window. Ask for that as a separate line in the model.
Costing it out at Hawaii electricity prices
The 30 percent federal Residential Clean Energy Credit under Section 25D expired for property placed in service after December 31, 2025, so a cash or loan purchase in Kaneohe receives no federal tax credit. Section 48E survives at 30 percent for third-party owners under leases and power purchase agreements.
The state RETITC under HRS Section 235-12.5 remains at 35 percent of actual cost capped at $5,000 per system, where a residential system is 5 kW of total output capacity, so a larger installation may comprise more than one system.
Net metering is not available, and neither are Customer Grid-Supply, Customer Grid-Supply Plus, Smart Export, Customer Self-Supply or the Standard Interconnection Agreement, all of which are closed to new customers.
Ask any installer to rebuild the projection from the RETITC, BYOD+ where storage is included, the confirmed Smart Renewable Energy track, and the Oahu 2025 residential average of 40.54 cents per kWh. The track is the input that most often makes an otherwise reasonable model wrong.