Hawaii has the most aggressive clean energy goals in the United States—and while the state has already deployed significant amounts of wind and solar power, the utilities on its islands need to know how their grids will operate with increasing amounts of renewable energy.
To shed light on the subject, the U.S. Department of Energy (DOE) and its partners have collaborated with local Hawaiian companies to complete the Hawaii Solar Integration Study—a first-of-its-kind detailed technical examination of the effects of high penetrations of solar and wind energy on the electrical grids on the Hawaiian islands of Maui and Oahu.
The National Renewable Energy Laboratory’s (NREL)’s recently released Hawaii Solar Integration Study Executive Summary highlights the key findings of the multiyear effort, which was jointly sponsored by the Hawaii Natural Energy Institute, DOE, Hawaiian Electric Company, Inc., and Maui Electric Company, LLC, under the auspices of the Hawaii Clean Energy Initiative (HCEI). General Electric conducted computer modeling and analysis of the Maui and Oahu transmission-level grid components. DOE’s National Renewable Energy Laboratory (NREL) formed a technical review committee to help guide the effort and leverage grid integration expertise from U.S. and international organizations.
The study included detailed computer modeling and simulations of the generation and transmission systems on each island to examine how future scenarios of high penetrations of solar and wind power will affect generator operations under normal system configurations. The distribution-level impacts were not assessed in the study.
The results provide a deeper understanding of the differences between distributed solar photovoltaic (PV) systems, centralized PV power plants, and wind power in terms of variability, ability to curtail power output, grid support functions, and characteristics relative to the load. The study found that adding large amounts of new solar power to the electric grids on Maui and Oahu—enough to achieve roughly 20% renewable energy penetration—will create operational challenges that could affect grid reliability, but those challenges are manageable for the scenarios studied with the recommended mitigation approaches and assumed system upgrades. However, the costs associated with the recommended mitigation approaches must be assessed relative to the identified benefits.
Ultimately, the insights from the Hawaii Solar Integration Study form a large body of knowledge for future grid integration studies, and the results can be used to further our understanding of grid integration in other island systems as well as in mainland U.S. systems with high regional solar and wind penetrations.
Read the full DOE SunShot Initiative-funded Hawaii Solar Integration Study Executive Summary.