Led by Vehicle Projects LLC, an international consortium has developed a 160-kW, 23-tonne fuelcell mine loader, a key production element of underground mining (see illustration). The project, commencing in 2002, is nearly complete as an innovative technical development project. We expect the fuelcell loader to be demonstrated in an underground gold mine in late 2007.
Based on the empirically determined duty cycle, its powerplant (see illustration) is a fuelcell-battery hybrid using 90-kW (nominal) PEM fuelcell stacks (manufactured by Nuvera Fuel Cells Europe, Milan, Italy) supplemented by a 70-kW transient-power nickel metal-hydride battery.
A fuelcell-battery hybrid powerplant design was chosen because of high but narrow power peaks in the duty cycle (see illustration) and the ability to recover some of the vehicle kinetic and potential energy as it descends ramps. With parasitic losses estimated to be no more than 20 kW (77% efficiency), the powerplant will be capable of delivering 70 kW of continuous net power and 140 kW peak net power. This compares favorably to the diesel version of 123-kW peak net power.