Refueling and On-board Storage System Options for Hydrogen-Powered Underground Mining Equipment <xref ref-type="fn" rid="FN1">*</xref>

Researchers at the Spokane Research Laboratory of the National Institute for Occupational Safety and Health studied alternatives to the use of diesel equipment in underground mines, as a means of reducing health hazards. Two of the alternatives being considered are battery-powered equipment and hydrogen-powered equipment. While battery-powered equipment is clean, recharging or replacing a battery takes longer and can be less convenient than refueling diesel equipment. In addition, the amount of electricity available from a battery is far less than the electricity available from a diesel hybrid configuration of comparable weight. Hydrogen-powered equipment faces similar challenges to those being faced by battery-powered equipment. However, if enough hydrogen can be put on-board the equipment quickly and conveniently via safe refueling options, then hydrogen-powered equipment can be competitive.

Refueling options and specifications are determined by the on-board hydrogen storage system chosen for a given application. Three main underground refueling options are identified. Parameters to consider when designing and choosing an on-board hydrogen storage system are discussed.

Safety and cost issues for hydrogen refueling options are included. However, the safety and costs for hydrogen refueling cannot be fully analyzed without demonstration projects. The relative safety and costs of diesel and batteries as compared to hydrogen are beyond the scope of this paper.