Ann: Quarterly Activities/Appendix 5B Cash Flow Report, page-112

Fuel cells use a battery, in any case, so there is potential there.

https://ieeexplore.ieee.org/stamp/stamp.jsp?arnumber=10174620

batteries are preferred for shorter distances and lighter
vehicles, while for higher millage and heavier vehicles where
more kWh is required, the fuel cell starts to be competitive
since it could provide a better overall volume and weight than
batteries [50]. That is the reason why, at the moment, the
railway market scope for hydrogen fuel cells is focused on
regional trains with more than 80 km of nonelectrified route,
relatively lower frequency of trains, and limited inactive time,
which does not permit battery charging

Finally, the battery has a higher power density than the
fuel cell (see Table 1), and for this reason, a fuel cell system
for railway usually includes a battery. While the fuel cell
provides the average power, the battery absorbs fast power
changes (i.e., recovering kinetic energy during braking) and
provides peak power during acceleration [54]. The battery is
also used to provide the start-up power for auxiliary loads
(i.e., air and heating, ventilation, and air conditioning (HVAC)
compressors, motor ventilation fans, etc.) [34], [55]