Hawaii relies heavily on imported fuel — and bears the cost. The state is exploring options from solar to geothermal to break free from fossil fuels.
Situated as an island chain in the central Pacific with no domestic oil or natural gas reserves, the 50th U.S. state has historically depended on foreign fossil fuels to drive its economic activity.
Imported petroleum powers a significant portion of the electricity grid, along with the maritime and aviation transportation that Hawaii depends on for moving residents and goods — and for bringing nearly 10 million tourists to its beaches each year.
Hawaii started cutting this fuel reliance in 2015 when it became the first U.S. state to pledge a shift to 100% renewable electricity by 2045. The objective was to tap into locally sourced solar, wind, bioenergy, hydropower, and geothermal energy found in its volcanic terrain.
That goal was broadened to cover the entire economy in 2018, with Hawaii establishing a groundbreaking "net-negative" carbon emissions target for no later than 2045. Additionally, a global first youth-led climate lawsuit compelled the state to cut carbon in the transportation sector by the same year.
Peter Sternlicht, a board member of the renewable energy nonprofit Sustainable Energy Hawaii, notes that such forward-looking clean energy objectives that "minimize, or completely remove, reliance on imported energy" have been motivated by a desire for energy independence.
Hawaii's youth charts a course out of the climate crisis
To view this video please enable JavaScript, and consider upgrading to a web browser that supports HTML5 video
As the most recent oil price spike triggered by the U.S.-Israel conflict with Iran reverberates through world markets, this aim stays especially pertinent. But how can a decarbonized, self-sufficient energy system be realized within two decades?
The hurdle
"The state requires numerous policies if it's going to achieve its 2045 target," said Paul Bernstein, an economic policy expert at the University of Hawaii.
Hawaii's various islands have distinct energy requirements shaped by their population sizes and geography. The island of Oahu, home to the state's biggest city, Honolulu, will be particularly tough to decarbonize.
"On Oahu, where population density and land limitations make the shift more difficult, the state is focusing on grid upgrades, more efficient generation, and substantial private-sector investment to back large-scale renewables and storage in the coming years," said Mark B. Glick, chief energy officer of the Hawaii State Energy Office.
Meanwhile on Maui, after a 2023 hurricane knocked down power lines that ignited wildfires killing 102 people, the state energy office says it has been tough for Hawaiian Electric, the state's largest utility, to maintain an affordable transition to renewable energy.
Even in areas where wind, solar, and batteries are aiding the shift, and with roughly 50% of homes on Oahu equipped with rooftop solar, Glick says geothermal energy must play a bigger role in the energy mix.
On Hawaii Island, the state's largest, abundant geothermal energy had been captured to supply a maximum of around 30% of its electricity in 2017. Output was later diminished by a volcanic eruption, but authorities are planning a 20% capacity increase by late 2026.
A major difficulty for Hawaii is cutting carbon from shipping and air travel, worsened by its reliance on planes for tourism.
"Virtually all our goods are imported from elsewhere," pointed out Paul Bernstein. He says sustainable aviation fuel and improvements in plane efficiency will help lower air emissions, but that electrifying flights remains a distant prospect.
Routes to decarbonization
In 2022, the Hawaii state legislature passed a law requiring the state energy office to "assess pathways" and to meet the state's "economy-wide decarbonization objectives."
A study commissioned by the state legislature outlined decarbonization options in which Hawaii's energy sector could shift within decades. This would require solar, wind, and storage to be "rolled out at an unprecedented pace," internal combustion engine vehicles to be eliminated in favor of zero-emission EVs, and buildings to be upgraded for better heating and cooling efficiency.
Furthermore, larger amounts of sustainable aviation fuel would need to replace conventional jet fuel needed for air travel.
But the study also notes that biodiesel, biomass, geothermal, and hydropower generation would need to assume a "significant role" if all Hawaiian islands are to reach the 2045 net-zero target.
A phase-out of fossil fuels could also be sped up with a carbon tax that raises the cost of oil or gas to encourage the shift to clean energy. Meanwhile, existing taxes on each barrel of imported fuel are already funding decarbonization initiatives.
A carbon tax could also be essential for developing geothermal energy, which stays the greatest hope for a transition to clean, domestic power. A relatively small geothermal plant typically uses underground volcanic heat to produce steam that spins a turbine to generate zero-carbon electricity.
"The State is conducting resource characterization of geothermal potential to better understand where geothermal can be developed, consistent with cultural values and community interests," said Glick.
While it was long thought that this energy source was not feasible on the most populous island of Oahu, more recent discussions suggest "that geothermal actually could be available where it's needed most," said Paul Bernstein.
"If that were the case, then that would really change the game," he added.
Although production costs are fairly low over a facility's lifespan, uncovering geothermal resources can be expensive, and much more investment will be required during the exploratory phase. Local consultation will also be crucial due to opposition from native Hawaiian communities over tapping into sacred volcanoes.
Renewable obstacles and calls for LNG
Given that it will be challenging to sufficiently boost geothermal energy in the next 20 years to reach the 2045 transition targets, the Hawaii state government has recently considered lower-emission "transition" fuels to keep up momentum away from high-polluting energy.
Hawaii is weighing the retirement of inefficient oil-powered electricity generators and replacing them with a single high-efficiency gas-fired generator fueled by imported liquefied natural gas (LNG).
This state-of-the-art power plant would cut greenhouse gas emissions by 20% over 20 years and be 20% cheaper than oil-fired energy — Hawaii's electricity is the most expensive in the U.S.
Mark Glick of the Hawaii State Energy Office says the more technologically advanced gas power plant is better suited to "increase renewable integration" into the grid.
But experts say that while LNG is cheaper than oil and produces lower emissions, the costs of cooling, shipping, and regasification are also high.
If renewable energy continues to grow alongside battery storage, LNG plants could become expensive, underutilized assets. "Solar and battery systems are already competitive with fossil fuels and avoid the risks tied to global fuel markets," noted analysis by the University of Hawaiʻi Economic Research Organization.
Edited by: Tamsin Walker
Hawaii reduces emissions in historic climate settlement
To view this video please enable JavaScript, and consider upgrading to a web browser that supports HTML5 video