Think B.I.G. Hawaiʻi← All toolsThink B.I.G. Hawaiʻi · Energy Self-Reliance (ESR) framework · Statewide
Hawaiʻi imports most of the energy it uses: oil for power plants, gasoline and diesel for cars and trucks, and fuel for ships and interisland flights. Renewables now supply about 38% of the state’s electricity, but electricity is only part of the picture. Counting every fuel, only about 11–14% of the energy used on each island comes from island sources.
This model tracks that bigger number, island by island. For each island it starts from 2025 data, including utility renewable-energy reports and state fuel-tax records for gasoline, diesel and aviation fuel. It converts every fuel to the same energy units, so electricity, transport, shipping, flights and industry can be added together. A simple year-by-year model then adds the projects already under contract or out to bid, continued rooftop solar growth and gradual EV adoption, to show where today’s plans lead. The 95% pathway goes further: faster solar and storage, firm renewables, electrified industry, island-made fuels for boats and planes, and EV sales climbing along an S-curve, from today’s 14% of new cars to about 63% in 2035 and 91% in 2040, a hopeful but plausible pace. Because cars stay on the road about 22 years, that last step sets the pace: on this path no island reaches 95% until about 2059, and the Big Island not until after 2060. Faster EV sales plus trade-ins of old cars and island-made fuels could get there around 2040; the island pages let you try that. These are planning sketches, not utility forecasts; each island page lists its assumptions and sources.
On the map, every major power plant is sized by capacity and colored by fuel, and each island shows its electric grid’s renewable share and its all-energy self-reliance. Play the history since 2005, the buildout on today’s plans, or the 95% pathway. Select an island to open its detailed map and a simulator where you choose what to build and how fast.
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Circles are power plants: area ∝ nameplate MW, colored by technology; dashed outlines are planned, not yet built, or never built. In the 95% pathway, the large dashed green circle on each island shows the extra renewable energy that island’s simulator pathway adds beyond current plans (sites not mapped). Niʻihau and Kahoʻolawe have no utility grid. Statewide shares weight each island by its 2025 generation before 2025, and use model totals after. Plant locations are approximate.
Grid renewable share: official RPS basis (share of generation). All-energy self-reliance: island renewable electricity used, off-grid solar and island-made fuels as a share of all energy used, including road, marine, interisland aviation and industry (ESR framework). The 95% pathway is each island simulator’s “ESR pathway” preset, with EVs limited to what fleet turnover allows (Hawaii EV Association calculator method).
Cars and trucks are the biggest piece of Hawaiʻi’s imported energy, and the slowest to change. Pick how fast EV sales climb to see how long the old gas cars take to cycle out.
Each square is 1% of the state’s 1,082,932 passenger vehicles (DBEDT, September 2026). Green: electric; terracotta: gas and diesel.
How this works: about 1.08 million passenger vehicles, and about 50,000 new ones enter each year (46,753 new retail registrations in 2025, plus ex-rental cars) as the oldest retire, so a new car stays on the road about 22 years. Today EVs are 13.8% of new sales (HADA, 2025); the curve sets that share each year from 2027 on, rising along an S-shaped path from today’s 13.8% toward the long-run share. Today’s EVs, including many early Leafs, leave the road at about 6% a year, matching DBEDT’s net gain of 3,811. A rough guide, not a forecast. The island pathways on this site use the same fleet method. Calculator adapted from the Hawaii EV Association.
History: Hawaiian Electric historical RPS data by island (share of sales to 2021) and RPS reports (share of generation from 2022, Act 240); KIUC RPS filings and annual results. 2025 actuals: Big Island 57.3%, Kauaʻi 52.8%, Maui County 41.6%, Oʻahu 32.3%. Projections come from each island page’s model (current contracts, the 2026 IGP RFP for Oʻahu and Big Island, rooftop trend, slow EV uptake) and its ESR pathway preset; open an island’s “How this works” section for its assumptions and sources. Statewide history before 2025 weights each island by its 2025 generation, an approximation. Interisland flight paths are decorative.
Save every island’s year-by-year results (current plans and the 95% pathway) and the history since 2005 as a spreadsheet, or a short PDF report. The map picture shows the year currently selected on the map’s slider.