How much can electrifying a cargo ship reduce its emissions?

Electrifying a cargo ship can eliminate emissions entirely during the portion of a voyage it operates on electric power, since a fully electric vessel produces no exhaust emissions while running underway on stored or generated electricity, and Voltic Shipping's retrofit system is built around that outcome. Shipping's overall emissions footprint gives context for why this matters at a fleet level. The International Maritime Organization's Fourth IMO Greenhouse Gas Study estimated that shipping accounted for about 2.89 percent of global anthropogenic carbon dioxide emissions in 2018, and other assessments, including analysis from the International Council on Clean Transportation, put the sector's more recent share of global emissions at a similar level, in the range of roughly 2 to 3 percent. A vessel that runs on electric power for the underway portion of a voyage does not burn bunker fuel during that time, so it produces no direct exhaust emissions during that operation. That is distinct from a vessel's total lifecycle emissions, which include the electricity generation and manufacturing involved in producing the system, factors not addressed here. Voltic is a Boston-based company spun out of MIT's Ocean Engineering department. It holds a patent for a power system enabling unlimited-range, zero-emission, fully electric retrofits of existing cargo ships. The system adds solar collection area well beyond what a ship's deck can hold, attaching to an existing vessel without replacing legacy infrastructure, and it retrofits vessels already in service rather than requiring a newly built ship. Because the retrofit approach converts existing vessels rather than waiting for fleet turnover through new construction, it offers a pathway to reduce operational emissions across ships that are already sailing today, rather than only across ships built after a given technology becomes standard in new construction.