Alternative Fuels/Technologies


Biofuels are a renewable energy source that can be stored and transported in a manner similar to fossil fuels. They can often be used in existing equipment and be blended with petroleum fuels. Biofuels categorically covers a variety of substances including biodiesel, ethanol, and biogas, among others.


Biodiesel is a domestically produced, renewable fuel that can be manufactured from vegetable oils, animal fats, or recycled restaurant grease for use in diesel vehicles. Biodiesel’s physical properties are similar to those of petroleum diesel but it is a cleaner-burning alternative that can result in a 75.8% reduction in carbon dioxide emissions. It is non-toxic and biodegradable.

In Hawaii, biodiesel is produced locally by Pacific Biodiesel on Maui and Hawaii Island. Pacific Biodiesel’s Hawaii Island refinery utilizes state-of-the-art distillation technology to produce the nation’s highest quality biodiesel and was the first facility in the world to be certified by the Sustainable Biodiesel Alliance for its sustainable production and distribution practices.

Many fleets in Hawaii have integrated 20% biodiesel into their diesel blends.


Ethanol is a normal component of today’s gasoline. Over 40% of the gasoline in the United States contains ethanol and the percentage is projected to increase. Hawaii State law requires all gasoline sold for vehicles to have 10% ethanol blended (E-10). Ethanol is an alcohol-based fuel produced from plant sugars such as corn and sugarcane or from cellulosic feedstocks (grass, wood, crop residues, or old newspapers). Ethanol is used to reduce carbon dioxide emissions from gasoline.


Biogas, also known as renewable natural gas (RNG) or biomethane, is natural gas or methane produced from organic materials such as wastewater treatment plants, landfills, or agricultural crops, by anaerobic digestion. Because biogas is chemically identical to the fossil-fuel derived natural gas, it can be used in existing natural gas distribution systems and must be compressed or liquified for use in vehicles.

Locally, Hawaii Gas opened the first renewable wastewater biogas facility in late 2018 at the Honouliuli Wastewater Treatment Plant in Ewa Beach.


Plug-in electric vehicles use rechargeable onboard batteries to store from the electrical grid or rooftop solar to power one or more on-board electric motors. Plug-in hybrid vehicles can use both the onboard battery as well as a gasoline backup, while full battery electric vehicles only have the battery and no gasoline backup. These battery electric vehicles produce no tailpipe emissions but do have upstream emissions associated with the production of electricity.

However, even with the electric grid as it is today, EVs are still more environmentally friendly to fuel than their gas-powered counterparts. Using 2016 electricity production numbers for the state, an EV in Hawaii releases approximately 40% of the carbon dioxide released by a 22mpg gas-powered car on the road.

There are up-front cost premiums associated with EVs at this stage, but there are also fuel and maintenance cost savings over the lifetime of the vehicle, and they are therefore considered cheaper to own over the lifetime of the vehicle. As battery technologies improve and prices drop, EVs are expected to begin reaching up-front cost parity with gas-powered cars around 2024.

Many people can conveniently charge their electric vehicles at home, by plugging it in overnight and topping off the battery. However, for those living in multi-unit dwellings such as apartments and condominiums, a strong public charging network is important.


Currently, vehicles with EV license plates receive free parking in City and County parking lots and metered parking across the states. They can also park for free at airports for up to 30 days.

There is also a $7,500 federal tax credit on all new full battery electric vehicle purchase, to be used as a credit on the next year's taxes. Plug-in hybrids receive $2,500 for the first 5kwh battery capacity plus $417 for each kilowatt-hour of battery capacity after that. The full credit amounts are only available until a particular manufacturer sells 200,000 qualified EVs, at which time the credit phases out for that manufacturer over a period of time. Currently, only Tesla and Chevrolet have reached their 200k car limit, and the tax credit has begun to scale back.

EVs in Hawaii

A key component of reducing fuel demand and utilizing locally produced renewable energy as Hawaii moves toward its 100% Renewable Portfolio Standard will be a vibrant plug-in electric vehicle (EV) market. All four Hawaii Mayors set goals of 100% renewable ground transportation by 2045, and to reach that goal will require strong investment in EV charging infrastructure and strong incentives for EV owners in early stages of adoption.

EV Charging

The U.S. Department of Energy’s Alternative Fuels Data Center hosts an up-to-date database of EV chargers and as of publication, lists Hawaii as having 266 publicly available Level 2 and DC Fast Charging stations with 524 charging outlets. Locations can be accessed through a variety of EV charging phone apps including PlugShare, EV Stations Hawaii, Chargeway, and other company-specific sites. Hawaiian Electric also operates a public DC Fast Charging network across their areas of service.

EV Organizations & Resources

Many local resources exist for those interested in EVs or current EV owners. Drive Electric Hawaii is a local hub of public and private members that are committed to educating the public about electric vehicles and Big Island EV Association and Kauai EV are community groups where EV owners connect and share.

Hydrogen and Fuel Cells

As the simplest and most abundant element in the universe, hydrogen can be used as a fuel for internal combustion engines (ICEs) or fuel cell electric vehicles (FCEVs). Fuel cells convert hydrogen into electricity through an electrochemical process and are generally twice as efficient as a combustion engine. Fuel cells produce zero emissions and have a similar range and refuel times as gasoline powered vehicles.

The first publicly available hydrogen refueling station and hydrogen electric vehicles have come on the market in Hawaii with the 2018 launch of Servco Toyota’s Mapunapuna Hydrogen Refueling Station and the Toyota Mirai.

The Hawaii Center for Advanced Transportation Technologies (HCATT) runs numerous hydrogen demonstration projects including a fuel cell hybrid step van, fuel cell hybrid aircraft tow vehicle, and fuel cell powered light cart, among others. HCATT is a federally funded project administered by the Hawaii Technology Development Corporation (HTDC).

Hawaii Natural Energy Institute, an organized research unit of the School of Ocean Earth Science and Technology of the University of Hawaii at Manoa, performs research, conducts testing and evaluation, and manages public-private partnerships across a broad range of renewable technologies to reduce Hawaii’s dependence on fossil fuel. Some of those research projects involve fuel cell and hydrogen technologies.