I’m no engineer so don’t expect a crazy in debt analysis from me, I’m just saying they already use overhead cables. Some electric trains have batteries for short movements away from overhead lines… I’m assuming this is a similar idea, recall these things have multi ton engines that are being removed not just diesel. If that huge engine is only being used for short distances it may be viable in the future to change those out for batteries as the electric drive system is already in place what would be removed is the diesel (more energy dense than battery I know) and the massive diesel engine and all it’s components, (all together likely close to the same if not less energy dense for short trips from the cables to the load site and back) considering all the electric system really needs to add is batteries and a controller it may be possible that the battery powered trucks could be viable in the future given the site has the proper infrastructure to support it.