The Port of Oslo, Norway is anticipating the arrival of its first battery-powered trash collection boat. The newcomer is being built domestically by aluminium specialist Grovfjord and, upon delivery in December 2019, she will replace the port’s existing, biofuel-powered rubbish skimmer Pelikan, which is credited with having removed some 1,500tonnes of trash from the area since 1989.
An all-electric solution was specified for the newbuild, as part of the port’s commitment to erasing fossil fuel usage within its jurisdiction. According to port director Ingvar M. Mathisen: “When possible, we choose electric… all other vehicles we use [run] on biofuels. This reduces our annual CO2 emissions by 150tonnes a year.” The replacement skimmer boat will measure 12m x 7.5m and will use a bow-mounted, 300kg-capacity hydraulic front loading basket to collect debris floating on the water surface.
Corvus Energy will supply the boat’s 550kWh Orca energy storage system (ESS), which will power two Danfoss electric engines, rated 107kW apiece. Corvus claims that the ESS’ capacity will enable a “full working mode” of four to five hours before a recharge is required. It should take about two hours to charge the batteries, Corvus adds. The engines will drive a pair of four-bladed, 925mm-diameter Helseth propellers. Additionally, the boat will be fitted with solar panels, to capture energy for the onboard navigational systems.
The new vessel will also utilise a mini-dynamic positioning (DP) system, supported by four electric side thrusters, rated 37kW apiece. Two Palfinger deck cranes have been installed, port and starboard, to retrieve floating objects. One features a lifting torque of 7.4tonnes per metre; the other, a lifting torque of 23tonnes per metre, permitting it to lift heavier items from the water. The boat will also be fitted with an echo sounder, to detect subsurface trash.