Can the Mackinac Island Ferry Be Powered by Solar Energy?

Mackinac Island in the state of Michigan, United States of America (USA), is one of the most visited summertime destinations in the country. The island attracts over a million tourists in the short period of 6 months. The only commute to the island is using ferries that travel to the island from Mackinaw City and St. Ignace. In 2022, a study was conducted by the Advanced Power Systems Research Center (APSRC) at Michigan Technological University on the potential benefits of electrification of the ferry from a technical, environmental and economic standpoint. The results from the study concluded that while the retrofitting of the Mackinac Island ferry to an electric ferry was feasible based on components available in the market, electrification would lead to an increase in the CO2 emissions. The economic analysis showed that the electric ferry would result in significant financial losses to any company operating the ferry. The overarching conclusion was that an electric ferry powered by Michigan’s electric grid was not the optimum solution for that time based on both carbon emissions as well as Total Cost of Ownership (TCO). The current work builds on the study completed in 2022 to determine whether an electric ferry powered by local solar energy can help reduce CO2 emissions as compared to the baseline diesel engine-powered ferry. The analysis includes sizing the solar array based on the solar radiation received by Mackinaw City, the CO2 emissions in the manufacture of solar panels based on a lifecycle assessment (LCA) of solar photovoltaics and the addition of battery energy storage as a means of energy storage between ferry trips to determine if the carbon footprint of the electric ferry can be reduced by powering it with energy from solar photovoltaics. Ferry drive cycle data used for this analysis is the same as that collected for the original study, although the appropriate parameters relating to Michigan’s electricity grid and emissions from battery manufacturing have been updated based on technological changes and the addition of different energy sources on the Michigan grid. This work also includes economic considerations for all potential electrification scenarios discussed in this work.