What are renewable energy zones, and why are they important?
At a glance
- Essential building blocks of Hawai'i’s clean energy future
- Bundle development efficiently, ensuring new generation projects can seamlessly “plug into” the grid through transmission upgrades
- Generate economic development and create jobs and workforce training opportunities in the renewable energy industry
- Help minimize and manage impacts to communities and the environment
- Support long-term reliability and allow for more stable electricity rates
- Complement ongoing safety and wildfire mitigation work
O'ahu
Renewable energy zones
Group 1
- Potential: 120 MW
- Interconnection: Hoohana 138 kV substation
Potential: 120 MW
Interconnection: Hoohana 138 kV substationGroup 2
- Potential: 324 MW
- Interconnection: Ewa Nui 138 kV substation
Group 3
- Potential: 588 MW
- Interconnection: Kahe 138 kV substation
Group 4
- Potential: 331 MW
- Interconnection: Waiau 138 kV substation
Group 5
- Potential: 608 MW
- Interconnection: Halawa 138 kV substation
Group 6
- Potential: 147 MW
- Interconnection: Koolau 138 kV substation
Group 7
- Potential: 66 MW
- Interconnection: Koolau 138 kV substation
Group 8
- Potential: 1,160 MW
- Interconnection: Wahiawa 138 kV substation
Renewable energy zones (REZ) are designated areas with strong potential for clean energy generation, such as solar and wind, and efficient connection to the grid. These zones serve as the “building blocks” of the clean energy grid.
By focusing renewable projects in the right places and allowing planned, coordinated construction of essential grid components like transmission, renewable energy zones help streamline the connection of clean energy projects into the grid, reduce costs, minimize impacts and deliver reliable energy to customers.
FAQsREZ are a key part of the Integrated Grid Plan
They support a coordinated, statewide effort to reduce carbon emissions. Through the renewable energy zones program, Hawaiian Electric is working alongside state leaders, agencies, communities and developers to build the infrastructure needed to power Hawai'i safely and sustainably.
What will renewable energy zones include?
Renewable energy zones will include power generation, like wind or solar, and transmission infrastructure to connect clean energy to customers. Transmission is a crucial component of the future grid.
We will need to build new transmission infrastructure as part of renewable energy zones to expand the grid’s capacity. New transmission will carry more electricity to meet customers’ growing demand for power.
What is transmission?
Transmission includes power lines and substation equipment that transport high-voltage electricity (such as 138 kilovolt or 69 kilovolt) over long distances and are typically held up by towers or poles. They are like highways, as the lines can move power from where it’s generated to substations, and eventually to customers.
Why now?
The Public Utilities Commission (PUC) has directed Hawaiian Electric to identify at least two renewable energy zones on O‘ahu by the second quarter of 2026.
Establishing these zones early helps streamline future renewable projects and the development of transmission lines to deliver clean energy to areas where it’s needed most.
Transmission infrastructure takes much longer to build (often 10 to 20-plus years) while clean energy projects like solar can be developed in just 2 to 5 years. Planning and building transmission must start well in advance so the grid is ready when new clean energy comes online.
Renewable energy zones help us plan ahead so future projects and grid upgrades can be coordinated, which can help reduce impacts on communities and the environment. This work lays the foundation for a more connected, resilient energy system that reflects a shared commitment to a carbon-neutral Hawai'i.
Timeline of EventsWhat are the benefits?
Click on the diamonds to find out
Reliability
- Improved reliability and faster restoration when outages happen, including during extreme weather
- Expanded grid capacity and more modern infrastructure, improving system resilience
Clean energy
- Support Hawai‘i state law to achieve a net-zero carbon economy by 2045, as outlined by the Public Utilities Commission and Governor’s Executive Orders
- Support the growing need for electricity and retirements/replacements of aging generators
Stable electricity rates
- More stable electricity rates in the long-term, as local clean energy generation reduces Hawai‘i’s reliance on imported oil and fluctuating global prices
- REZ is about building a more stable energy system that supports long-term bill stability
Economic development
- Renewable energy zone development takes place over many years. During that time, workers and project teams spend money locally—supporting nearby restaurants, hotels, supply stores, and other small businesses
- Renewable energy zone construction creates job opportunities and supports workforce training in the growing renewable energy sector, helping build local skills that can benefit communities well beyond a single project
What does this mean for customers?
In the immediate term, as Hawaiian Electric moves through the evaluation process and selection of renewable energy zones, customers can expect to receive information and invitations to learn more and provide input about individual projects that are selected to move forward. To support the initial planning phase of these projects, you might see utility crews in your area as early as this year, conducting surveys and gathering information.
In the long-term, renewable energy zones are part of a larger effort to improve reliability, modernize infrastructure, and reduce dependence on imported fuel and stabilize rates. By supporting local energy production, renewable energy zones help protect customers from global price fluctuations.
This work lays the foundation for future renewable energy generation and transmission projects that will each individually undergo a rigorous process of community input and environmental review before approval and construction. Construction associated with renewable energy zones would begin in 2030 at the earliest.
Hawaiian Electric is committed to communicating proactively and transparently with our communities. We encourage you to sign up for our email list and reach out to our project team anytime.
