Electric ships face a hard constraint: their batteries can only take them so far before they must turn back and head to port. That ceiling has kept maritime electrification from reaching its potential — until now.
Engineers at SINTEF, a Norwegian research organization, say they’ve demonstrated a wireless charging system that lets electric vessels recharge while floating at sea, drawing power directly from offshore wind turbines. No cables, no physical connectors — just a magnetic field bridging ship and station across open water.
Plugs don’t survive the ocean — so they got rid of them
Conventional charging connectors are built for stability. They require firm, dry metal-to-metal contact to move electricity efficiently — conditions that simply don’t exist at sea. Waves, currents, and wind constantly shift both a vessel and any platform it’s connected to. Even small misalignments place serious mechanical stress on connectors, loosening contacts or interrupting power transfer entirely. When current flows through a connection that momentarily separates, electrical arcing becomes a real risk.
Saltwater compounds every one of these problems. It’s highly conductive and aggressively corrosive to exposed metals. Salt deposits and oxidation degrade charging contacts over time, raising electrical resistance and increasing the chances of overheating or outright failure. Conventional plugs aren’t designed for repeated immersion — water entering a connector can trigger short circuits and insulation breakdown, adding yet another layer of hazard in an already hostile environment.
These factors made traditional offshore charging not just inconvenient but fundamentally impractical. That reality pushed SINTEF’s engineers toward a different approach: eliminate the physical connection entirely.
Wireless power transfer, scaled up for ships
The solution SINTEF developed is based on inductive power transfer — the same underlying principle used in wireless phone charging, but engineered for a far more demanding environment. A transmitting coil inside the charging platform generates a rapidly oscillating magnetic field using alternating current. A receiving coil aboard the vessel sits within that field, and the changing magnetic flux induces an electric current without any physical contact between the two.
Both coils are fully encapsulated in waterproof materials rated to resist salt, algae, and moisture intrusion. That sealed design eliminates exposed electrical contacts, removing corrosion as a primary concern — and it means the system can tolerate the constant small movements between a vessel and a platform without interrupting power transfer.
“We’ve tested a possible solution that works almost like a regular electrical contact. But we can avoid all the problems because we transfer the power inductively by encapsulating the plug itself in materials that can withstand just about anything,” said Giuseppe Guidi, a senior research scientist at SINTEF.
The engineers are careful to note that this isn’t simply a matter of scaling up consumer technology. Achieving reliable inductive charging at offshore power levels required specially engineered cables, intelligent control software designed to minimize energy loss, and electromagnetic components built to handle extreme conditions. The physics are familiar; the engineering is not.
Wind turbines as floating fuel stations
The wireless charging system doesn’t exist in isolation — it’s the centerpiece of a broader infrastructure concept. The Ocean Charger project, led by shipbuilding company VARD and a consortium of green-energy maritime partners, launched in 2023 with the goal of developing a full-scale offshore charging solution that removes the need for vessels to return to shore.
The model relies on offshore substations that collect electricity directly from nearby wind turbines. When wind output is low, intermediate storage ensures charging remains available continuously. “The OSS hub functions as an electrical hub out at sea, collecting electricity from the wind turbines and making it possible to charge vessels directly, without traveling to shore,” said Håvard Vollset Lien, head of the Ocean Charger project at VARD. The substation operates as a persistent electrical hub rather than an intermittent one.
The long-term vision is a network of these hubs distributed along coastlines — beginning with Norway — where compatible vessels can stop and recharge mid-route as a matter of routine.
What this means for the future of maritime electrification
The sectors with the most to gain are those where returning to port for charging is most disruptive. Service vessels in oil and gas, offshore electrical infrastructure, and marine law enforcement all face operational constraints that shore-based charging can’t easily solve. A distributed network of offshore hubs could meaningfully extend their range and cut downtime.
More broadly, if that network scales, it changes the calculus for electric and hybrid-electric vessel design. Operators would no longer need to size battery capacity around worst-case return journeys — routes could be planned around charging stops instead.
Vollset Lien has gestured at what that future might look like: “Perhaps one day it will become a common sight for electric service vessels and coastal vessels to charge their batteries at sea and out in the shipping lane.” Whether that vision materializes depends on how quickly the infrastructure can be built and how broadly the technology is adopted — but for the first time, the engineering barrier to getting there appears to have a credible answer.