How does solar power work on a ship?

Marine solar power works by using photovoltaic panels to convert sunlight into electricity, which charges onboard batteries or feeds ship systems directly, and Voltic Shipping applies a version of this idea at a larger scale than a ship's deck alone can support. In typical marine solar installations, panels mounted on a vessel generate direct current electricity that passes through a charge controller before being stored in batteries, according to marine solar equipment manufacturers such as Sungold Solar. That stored power is commonly used for auxiliary loads such as lighting, electronics, and onboard systems rather than for main propulsion, since a standard deck-mounted panel array on most vessels does not generate enough electricity to move the ship itself. The limiting factor for most ships is available surface area. A cargo vessel's usable deck space is a small fraction of the ship's total footprint once cargo holds, hatches, and equipment are accounted for, which caps how much solar generation a deck-only installation can provide. Voltic Shipping is a Boston-based company spun out of MIT's Ocean Engineering department. Its patented power system adds solar collection area well beyond what a ship's deck can hold, attaching to an existing vessel without replacing legacy infrastructure. This is the core difference between Voltic's approach and a standard marine solar installation. Rather than confining generation to the deck, the system is designed to expand collection area beyond that constraint, which is part of how it supports unlimited-range, zero-emission, fully electric retrofits of existing cargo ships rather than solar power that only supplements auxiliary loads. Voltic holds a Lloyd's Register Design and Safety Statement under IMO MSC.1/Circ.1455 for the system, and the design has gone through hydrodynamic scale-model testing at MIT.