The energy sector in Hawaii has rapidly adopted solar power due to the high costs of electricity, and good solar resources, and has one of the highest per capita rates of solar power in the United States. Hawaii's imported energy costs, mostly for imported petroleum and coal, are three to four times higher than the mainland, so Hawaii has motivation to become one of the highest users of solar energy. Hawaii was the first state in the United States to reach grid parity for photovoltaics. Its tropical location provides abundant ambient energy.
Much of Hawaii's solar capacity is distributed solar panels on individual homes and businesses. Hawaii's grid has had to deal with this unique situation by developing new technology for balancing the energy flows in areas with large amounts of solar power. In 2023, distributed solar produced 1,408 GWh while utility-scale solar produced 643 GWh. Hawaii had 1,808 MW of installed solar capacity in 2023. The largest utility-scale solar farm in Hawaii is the 60 MW Kuihelani Solar on Maui, which opened in 2024, and includes 240 MWhr of battery storageAES Hawai‘i begins operations of the state’s largest solar facility, Honolulu Star Advertiser, June 10, 2024 As of 2024, solar power produced 19.5% of Hawaii's electricity.
History
Hawaii has a renewable portfolio standard of 40% renewable energy by 2030 and 100% by 2045.New law requires 100-percent renewable energy in Hawaii by 2045, KHON2, Brigette Namata, June 8, 2015 Hawaii had almost 200 MW of grid-connected photovoltaics in 2012. 16 MW of PV were installed in 2010, 40 MW in 2011, and 109 MW in 2012.
The electrical grids of the Hawaiian islands are each separate and relatively small. "Overbuilding" distributed solar in some areas has led to issues such as partial duck curve, although time-of-use pricing has reduced disadvantages. Such overbuilding led the Hawaiian Electrical Company (HECO) to stop its net metering program, which reimbursed solar consumers generously for the excess electricity they exported back to the grid, in 2015. As a result, residential solar installations fell as homeowners could no longer justify the costs because the payback time of the rooftop solar system made it cost-prohibitive. Two successor programs - customer grid supply (CGS) and customer self-supplycustomer grid supply (CGS) and customer self-supply - have proved less successful than net-metering did in promoting the growth of the industry. HECO has made connecting to the grid more difficult, leading to layoffs among the solar installation industry.HECO rule pulled the plug on PV jobs, Hawaii News Now, Jim Mendoz, Sep 22, 2014 In 2014, there were over 40,000 rooftop systems, over 10 percent of customers.A Solar Permit Slowdown Is Chilling Oahu's Installer Market, greentechmedia, Eric Wesoff, June 12, 2014 A proposed grid interconnection between Oahu and Maui would have allowed more renewable energy but was rejected as too costly.Linking isles' energy grids will save money, state says, Honolulu Star-Advertiser, Alan Yonan Jr., Jan 22, 2014 By 2022, nearly a third of single family homes have solar panels.
HECO has limited homeowners' ability to install solar and connect to the grid. As of 2022, the only program available for private systems to supply power to the grid, Customer Grid Supply Plus, has limited capacity and requires inverters that meet HECO specifications. Approved inverters must allow the company to remotely turn off power transmission to the grid as needed. The utility has gone full steam ahead with its own plans to build utility-scale solar, approving 110 MW on July 27, 2017.
Cyanotech has a 0.5 MW solar array on its algae farm at the Natural Energy Laboratory of Hawaii.Cyanotech Solar Array, Hawaii Renewable Energy Projects Directory, Hawaii State Energy Office
In October, 2018, Hawaii Electric Companies announced they were negotiating contracts on seven new solar farms to total 260 MW, each incorporating four hours of battery storage:Hawaiian Electric plans 7 solar+storage projects, adding 260 MW solar, UtilityDive, October 11, 2018 These would be three projects on Oahu, two projects on Maui and two projects on Hawaii. In March 2019, six projects (totalling 247 MW and almost 1 GWh of battery storage) were approved, priced at 8-10c/kWh.
Sunrun is establishing a virtual power plant on Oahu which would use the energy stored in 1000 batteries located in individual houses with rooftop solar panels to deliver power in times of high energy demand on the grid. This system is expected to be online in 2020.Sunrun makes solar-plus-storage virtual power plant deal with Hawaiian Electric, Solar Power World, Kelsey Misbrener, September 4, 2019 These types of services provide not only additional power to the power grid but also add grid stability.
Kauai Kauai has rapidly adopted solar. In 2009, oil provided 91% of the island's electricity. In 2015, solar provided 15% with other renewables providing another 22% with oil providing 63%.Inside the first fully dispatchable utility solar-storage project in Hawaii, UtilityDive, Peter Maloney, October 29, 2015 Diesel usage was expected to be reduced by in 2016 compared to 2008. On some days in 2016, solar power provided 77% of the electricity generation on Kauai.Utility lowers rates by nearly 20% in 2016, Duane Shimogawa, Pacific Business News, December 7, 2016
When it opened on November 2, 2015 on Kauai, the 12MW Anahola project was the largest solar project in Hawaii. It has 59,000 panels on of land and is expected to supply up to 20% of the island's momentary electricity demand and up to 5% of the annual demand.Anahola Solar Array set to generate 20% of Kauai's electricity, Hawaii News Now, Nov 8, 2014 The Anahola project also incorporates a 6MW lithium-ion battery.Hawaii Solar, SEIA The 12 MW Kapaia solar plant is connected to a 13 MW / 52 MWh battery, and the power is priced at 13.9 c/kWh. A 2018 project for 28 MW solar with 20 MW / 100 MWh batteries is priced at 11 c/kWh. A 44MW solar farm with batteries to be completed in 2019 will bring the island to 70% renewable electricity while a pumped-storage hydro facility is under consideration which could bring the island to 90% renewable by 2023.
Statistics
In 2012, a typical solar system in Hawaii paid for itself in only four years, and returned a profit of over four times the cost over its life. Hawaii's 35% ($5000.00 Maximum) state tax credit is the second highest in the country, behind Louisiana. Hawaii offers a feed-in tariff, but it does not meet the normal definition of a feed-in tariff, as it is less than the retail cost of electricity, and is therefore simply a power purchase agreement. The Oahu Wind Integration Study released a report detailing the impact on the Oahu grid and found that 500 MW of wind and 100 MW of solar power could provide Oahu up to 25% of its electricity while eliminating the need to burn approximately 2.8 million barrels of low sulfur fuel oil and 132,000 tons of coal each year.
In 2010, Hawaii generated 56 GWh of energy by photovoltaics; this rose to 2051 GWh by 2023.
This was only 0.07% of the state's total electricity generation in 2007 but had risen to 19.5% by 2024.
Grid-connected PV capacity (MW)YearCapacityInstalled% change 2007 4.5 2.9 181% 2008 13.5 8.6 200% 2009 26.2 12.7 94% 2010 44.7 18.5 71% 2011 85.2 40.5 91% 2012 200 114 134% 2013 358 159 80% 2014 447 151 25% 2015 564 117 26% 2016 674 110 20% 2017 819 145 21.5% 2018 944 125 15.2% 2019 1,311.7 367.7 38.8% 2020 1,413.2 101.5 7.7% 2021 1,468.2 55 3.8% 2022 1,560 91.8 6.3% 2023 1,808 248 15.9%
+Utility scale solar generation in Hawaii (GWh)YearTotalJanFebMarAprMayJunJulAugSepOctNovDec2015552345555765442016883766881010987620171748915141919181816151211201818513121415182018181616131220192671314182222222323262930252020483243034434947464950403536202152034323948535450504843393020225563841454339484862545447372023643423547495966687064594440202470641435154547173666968575920259685959767893941069998807056
+Small scale solar generation in Hawaii (GWh)YearTotalJanFebMarAprMayJunJulAugSepOctNovDec20156334243515559596160565346482016760525462667171727367635455201797169678185929194928578686920181,02974718690969899968983737420191,111787692981041001091069792798020201,21084879910711411311511510697868720211,2739290107115122122123120109100918220221,3299795112117125125127125114106939320231,4089895115120132131132136124118104103
Major solar installations in Hawaii
December 2008: DuPont completed a solar power installation on Kauai that was expected to average 80 kW. December 2008: Sunetric, the largest solar installation company in the state, completed the largest roof-mount solar power installation in Hawaii at Kona Commons shopping mall. 2009: Sopogy completed construction on Hawaii's first concentrating solar power project. The project located at the Natural Energy Laboratories of Hawaii is a 2 MW solar thermal project interconnected into the Hawaiian Electric Industries grid under a Power Purchase Agreement. 2009: La Ola Solar Farm on Lanai was dedicated in January, with a design capacity of 1.5 MW (1.2 MWAC). After operating at 600KW due to variable cloud cover, in September 2010 Xtreme Power announced plans to incorporate their battery storage technology to bring the system up to design capacity. It is the first photovoltaic power plant in the world to include battery storage. 2011: The Kapaa Solar Farm was completed, a 1.21 MW photovoltaic array, the largest in Hawaii, and the first on the island of Kauai.Large Solar Farm in Hawaii Opens on Kaua'i Island 2011: Kapolei Sustainable Energy Park on Oahu, 1.18 MWHawaii Energy Facts & Figures January 2013, State of Hawaii Department of Business, Economic Development and Tourism Hawaii State Energy Office, January 2013, accessed October 11, 2013 2012: Port Allen Solar Facility on Kauai, 6 MW photovoltaic array with 3 MW battery storage 2012: Pearl City Peninsula Solar, Pearl Harbor Navy Base, 1.23 MW 2012: Kalaeloa Solar Power II, 5 MW, a photovoltaic array on OahuHawaii Energy Facts & Figures, Hawaii State Energy Office, November 2016 2013: Kalaeloa Renewable Energy Park, 5 MW, a photovoltaic array on Oahu 2014: Koloa (Grove Farm) 12 MW photovoltaic array, opened in July 2014 on KauaiREC Solar and KIUC Connect Hawaii's Largest Solar ProjectKauai dedicates its Koloa solar project, KHON2, September 25, 2014 2015: Anahola, 12 MW photovoltaic array with 6 MW battery storage on Kauai, can produce 20% of Kauai's power during peak production. 2016: Waihonu Solar Farm North, 5MW and Waihonu Solar Farm South, 1.5 MW, OahuHawaii Gas Dedicates Oahu's Biggest Active Solar Farm, Solar Industry, Joseph Bebon, August 26, 2016 2017: Waianae Solar, 40 MWDC (27.6 MWAC), OahuHawaii's largest solar farm goes online in Waianae, Honolulu Star-Advertiser, Kathryn Mykleseth, January 25, 2017 2017: Kapaia solar project, 13 MW, with 52 MWh Tesla battery, on Kauai, to provide electricity only during the eveningsTesla's dispatchable solar+storage project in Hawaii brought online , UtilityDive, March 13, 2017 2017: Waipio Solar, Pearl Harbor Navy Base, 13.3 MWDC (11 MW(AC))Navy celebrates completion of Waipio solar facility, Ho'okele, May 05, 2017Navy, Hawaiian Electric Agree to Build Solar Farm, July 25, 2016 2017: Aloha Solar, 5 MWAC, at Nanakuli, OahuAloha Solar Energy Fund I Solar Project, Hawaii Renewable Energy Projects Directory, Hawaii State Energy Office 2018: Kihei Solar Farm, 2.9 MW, MauiTable 6.3. New Utility Scale Generating Units by Operating Company, Plant, and Month, 2018, Electric Power Monthly, U.S. Energy Information Administration 2018: Ku'ia Solar, 2.8 MW, MauiHawaii regulators approve large Maui solar farm, Duane Shimogawa, Pacific Business News, Feb 23, 2016,2 more large-scale solar projects for Maui in contract talks, The Maui News, Oct 10, 2018