Hawaii’s first solar panel installation on a commercial project dates back to 1976. The Mauna Lani Bay Hotel on the Big Island was the first to install solar panels. Since then, Hawaii has made significant progress in adopting solar energy, particularly in the commercial sector. As of the third quarter of 2024, the state has installed 2,060 megawatts (MW) of solar capacity, ranking 23rd nationally. This capacity is sufficient to power approximately 552,259 homes and accounts for 20.11% of Hawaii’s electricity generation.
Interest in maintaining the economic and environmental benefits of renewable energy is not waning, and commercial enterprises continue to invest in installations, including repowering the systems that are now aging.
Typically, systems are not replaced until the federal and state tax incentives including rebates, grants, investment tax credits (ITC) and accelerated depreciation have been fully utilized, usually 7-10 years after installation. Aging roofs also require photovoltaic (PV) systems to be removed and replaced, and depending on the PV system’s condition, this may be an ideal time to repower.
Repowering allows for all tax incentives to again be captured based on the total cost of the new system. New PV systems have a life of 20-25 years. Modules degrade at a rate of .08 -.1 percent annually and warranties typically are for up to 80 percent of expected production through the 20-year life. Inverters may also have extended warranties for the life of the system. Permitting and utility inter-connections are required for any repower.
These new systems are no different than installing any new PV system, with the exception of the additional cost of removal, demolition and recycling of the existing system.
Hawaiian Electric Company (HECO) has initiated new inter-connection programs and online applications. However, not all kinks have been worked out, and applications can take longer to process.
Repowering can have the additional benefit of using the most efficient equipment available. Many improvements to materials and equipment have been made since the original was installed. This may allow for more power to be added if needed or the same power generation in a smaller footprint.
Each project needs to be evaluated based on its unique attributes – whether itʻs design, system efficiency, platform conditions (e.g. roof) or financial/economic. Only then can a reasonable and effective plan be initiated.