Seattle's Elliott Bay Design Group has developed a unique solution for cold-ironing and electric-tug charging. Instead of permanent infrastructure installed at a pier inside the harbor, it proposes to mount a methanol-powered generating system on a barge and provide power to vessels out at the anchorage.
EBDG's "harbor power and charging barge" would look much like a bunkering barge, but instead of a transfer pump and a hose, it would carry a Wartsila W32M methanol-fueled generator and a shore power cable. The seven-megawatt generator set would be enough to take care of the cold-ironing load for a containership carrying reefer boxes, and it would comply with Tier IV emissions requirements.
The barge would carry enough fuel for 14 days of operation - far more than would be possible for an all-battery-electric solution or a hydrogen-based solution of comparable size, according to EBDG Principal-in-Charge Michael Complita.
The 200-foot barge would also carry the e1 Marine hydrogen reformer, which strips the hydrogen out of methanol so that the H2 can be used in fuel cells. That H2 would feed a fuel cell system to charge up a bank of onboard batteries, which would supply electric tugboats with fast charging.
"That's been a big concern in the towing industry: how do you go out and operate an electric tug in the harbor for eight hours and then bring it back to the dock to charge? With this approach, the tug never has to leave the harbor because it can fast-charge at the power barge," says Complita.
