Our Vision & Commitment

Hawaii Pathways to Net Zero

Hawaiian Electric understands the need to develop a comprehensive decarbonization strategy for Hawaii that considers all sources of carbon emissions, not just power generation. For this reason, we commissioned a study conducted by E3, a nationally recognized consulting firm, that describes the long-term, economywide decarbonization scenarios required to meet Hawaii’s target of achieving net-zero greenhouse gas (GHG) emissions by 2045.

The E3 analysis builds on Hawaiian Electric’s Climate Change Action Plan, which we announced in 2021 to cut carbon from power emissions 70% by 2030 compared with 2005 levels. This analysis shows that every industry and every individual will play a role in decarbonizing the Hawaii economy.

We hope that this study can serve as a catalyst for conversations around the challenge of economywide decarbonization and also as a resource for developing action plans.

View Hawaii Pathways to Net Zero


In 2018, Governor David Ige signed Act 15, establishing one of the most ambitious economywide greenhouse gas (GHG) emissions targets in the country. Act 15 requires a 2045 economywide net zero GHG emissions target for the state of Hawaii, which aligns with contemporary climate science's goal of limiting global warming to 1.5°C.

In addition, Hawaii is a member of the United States Climate Alliance (USCA) and shares the Alliance-wide target of 50-52% reduction in GHG emissions below 2005 levels by 2030. In July 2022, after the analysis for this study was already completed, Governor Ige signed Act 238, which sets a statewide greenhouse gas emissions limit of at least 50% below 2005 levels by 2030.

Hawaiian Electric has also instituted its own targets for emissions reductions from electricity generation. These include a 70% reduction in GHG emissions below 2005 levels by 2030 and net-zero GHG emissions by 2045, in line with the state’s economywide target. These targets are voluntary commitments made by Hawaiian Electric and are in addition to legal requirements under the state’s Renewable Portfolio Standard.

Major technological advances, especially in sustainable fuels and carbon-capture, and reaching consensus on land-use policy are some of what’s required for Hawaii to fully decarbonize over the next 22 years. With time fast approaching to meet these targets, the new pathways study advises that aggressive actions will need to be underway by 2030 to create a glide path to full decarbonization that is less steep than if actions are delayed.

The Purpose of this Study

Hawaiian Electric commissioned Energy and Environmental Economics (E3) to develop long-term, economywide decarbonization scenarios that meet Hawaii’s 2045 target. This study does not seek to define prescriptive approaches to achieving net zero in Hawaii, but rather provides an initial exploration of what might be needed to achieve this ambitious climate goal in terms of energy infrastructure, technology adoption and deployment, and supportive policies over the next two decades. This initial assessment of decarbonization scenarios focuses on the scale of the energy transition and the types of technologies and fuels that would be needed to meet Hawaii’s 2045 target.

The primary objectives of this study are:

To develop decarbonization pathways for meeting Hawaii’s economywide net zero by 2045 target that consider various options for emissions reductions in each sector of the economy.

To explore a range of potential electric loads that are consistent with economywide decarbonization and to compare these to Hawaiian Electric’s current load forecasts.

To estimate the quantity of decarbonized fuels that may be needed for end uses that are hard to electrify and to consider the potential sources of decarbonized fuels

To explore which sectors will require major policy or regulatory changes to support decarbonization.

Key Findings

The broad lessons and key findings from this study are summarized below.

1. Renewable electricity generation

Renewable electricity generation alone is necessary but not sufficient to meeting Hawaii’s decarbonization goals. Achieving electric-sector decarbonization goals may require an unprecedented scale-up in new generation capacity to serve both existing loads and new loads resulting from the electrification of transportation and buildings. However, decarbonization of electricity generation will not be sufficient to achieve Hawaii’s economywide net zero target.

2. Electrification and decarbonized fuels

Both electrification and decarbonized fuels will be required to decarbonize other sectors of the economy. In some sectors, such as on-road transportation, electrification is likely to be the key driver of emissions reductions. However, in other sectors such as aviation and marine transportation, electrification is likely to play a smaller role and decarbonized fuels will be required to achieve emissions reductions.

3. Primary challenges to achieving Hawaii's 2030 emissions target

Achieving the state’s 2030 target of 50% economywide emissions reductions will be challenging due to long vehicle and equipment lifetimes, long siting and development timelines in the electric sector, and a lack of near-term decarbonization options for aviation. The scenarios modeled in this study achieve 46-48% GHG reductions by 2030, reflecting ambitious effort across all sectors of the economy to meet the statutory 2045 target. However, these scenarios fall short of the 2030 target under Act 238, indicating that even more aggressive near-term action would be required to achieve 50% economywide emissions reductions by 2030.

4. Energy efficiency and conservation

The buildings sector has significant potential for energy efficiency and conservation, as well as several policies and programs in place to support energy efficiency. Energy efficiency and conservation support achievement of the net zero goal by reducing the total amount of zero-carbon electricity and fuels that must be procured, lessening the cost and land-use impacts of decarbonization.

5. Hawaiian Electric’s load forecasts and planning needs

By 2045, the level of electric loads aligned with achievement of economywide net zero are likely to be far above Hawaiian Electric’s existing load forecasts, which will have major impacts on Hawaiian Electric’s planning needs. Even after accounting for higher levels of energy efficiency, the decarbonization scenarios evaluated in the report result in 2045 electric loads that are 25-56% higher than Hawaiian Electric’s 2045 “base” load forecast. The level of electrification reached by different sectors will have important implications for the amount of zero-carbon generation and capacity that Hawaiian Electric will need to procure.

6. Decarbonization of aviation

Decarbonization of aviation will require a large quantity of decarbonized fuels and is likely to be one of the major challenges for meeting Hawaii’s 2045 net zero goal. The decarbonization scenarios evaluated in this report reflect 51-62% of 2018 demand for liquid (fossil) fuels in Hawaii. By 2045, about 80% of the decarbonized fuel demand may be from aviation. Depending on technological development, it may be possible to electrify short-haul inter-island flights among the Hawaiian Islands. However, most aviation fuel demands are for long-haul trans-Pacific flights to the US mainland and are likely to require decarbonized fuels. The future supply of decarbonized fuels is a significant risk to achieving carbon neutrality in Hawaii, with potential concerns regarding availability, cost, and sustainability. Carbon dioxide removal may be required if adequate decarbonized fuel supplies cannot be procured.

7. Carbon dioxide removal

Carbon dioxide removal will be required to achieve net zero in Hawaii, either through increased natural carbon sinks or negative emissions technologies. If GHG emissions from burning fossil fuels can be reduced to zero, the decarbonization scenarios still reflect 2045 totals of ~3 million metric tonnes per year of non-combustion GHG emissions. These non-combustion emissions, especially methane and nitrous oxide emissions from waste and agriculture, are challenging to lessen. Our interpretation of Act 15 is that any additional carbon sequestration will have to occur within the state of Hawaii. Thus, achieving the state’s net zero target will likely require land-use measures to enhance Hawaii’s natural carbon sinks and/or in-state deployment of negative emissions technologies such as direct air capture.

8. Additional policies and regulations needed

Additional policies and regulations are needed to ensure the deployment of decarbonization strategies outside of the electric sector. The electric generation sector has considerable policy and regulatory mechanisms in place to support decarbonization. However, other sectors of the economy do not yet have corresponding policies in place to ensure or support emissions reductions. Without additional sectoral policies, the state will not be on track to achieve the 2045 net zero target.