RE:RE:RE:RE:RE:RE:New pics on the websiteFuel cells do use oxygen but at a negligible rate. Fuel cells eliminate the need to swap out batteries to recharge which is important in a 24 hour operation like mining. Batteries also become less efficient as the shift wears on, slowing production. Batteries are also impacted by low temperatures.
Here is an example of fuel cell development in above ground mining equipment..