Wind Powered Conduction-Type Seawater Magnetohydrodynamic Generator in a Sailboat Keel

A sailboat under way can be the motive force for a magnetohydrodynamic generator built into its keel, which converts the motion of the hull through seawater into clean, renewable electrical energy. The hydrodynamic surface of a sailing vessel's keel has not previously been treated as a source of recoverable power, and a model of the sailboat which includes this term is developed here. The vessel is modeled as a coupling at an edge where a field differentiates the surface of the ocean from the atmosphere. Within this model the keel of the sailing vessel is considered as a site, or surface, of potential power generation. A superconducting magnet surrounding a cylindrical duct may be placed through, in place of, or affixed to the keel or keel bulb, the interior face of that duct being treated as a Faraday (conduction) magnetohydrodynamic (MHD) generator, with seawater as the conductive fluid. Seawater is passed through the duct by the vessel's motion across the shear between wind and water, and the relative motion of that conductive fluid across the interior generator face is transduced to direct-current (DC) electrical power. This design thus integrates a superconducting MHD generator directly into the keel of the vessel's hull, where it serves both as a novel power harvesting surface and as the primary righting mass. In high wind the vessel may carry overcanvased sail to maximize aerodynamic thrust. The MHD surface applies a longitudinal drag that opposes the surplus thrust and extracts it as power, capping the surge velocity so that stability is held by the mass of the magnet concentrated at the lowest point of the hull. The conductor itself is a ram-fed duct within a static superconducting dipole. As seawater moves through the duct the Lorentz force deflects ions laterally onto electrodes, producing DC power, while its reaction on the water acts as a regenerative brake, ensuring the vessel does not exceed its displacement (Froude) speed limit, with surplus leaving as electricity rather than as heel and leeway. A nominal configuration with a 12~T dipole and a magnet mass of 85--130 tonnes may deliver approximately 100~kW net, from 118~kW gross, to a DC bus, with no moving parts, no fossil or fissile fuels, and no anodic chlorine evolution. Chlorine has been a central barrier to the real-world deployment of MHD generators in commercial and civilian use. Chlorine is here suppressed by luminescent shunting: the surface of the generator is treated as a semiconducting electrochemical cell, a dense array of sub-threshold drains embedded in a platinum-iridium thin film, with the band edge placed in the potential gap between water oxidation and chloride oxidation, so that the overpotential energy which would have evolved chlorine is instead shunted into the photonic regime and emitted as 420~nm luminescence.