https://www.coherentmarketinsights.com/ongoing-insight/autonomous-rail-rapid-transit-1028
Mainly this type is autonomous train is powered by lithium-titanate batteries, though Hydrogen is expected to be a primary source powering trains by 2030 Hydrogen for locomotive power is expected to be driven by nuclear, wind, solar, and hydro-electric resources, as well as other evolving ways of generating hydrogen. Hydrogen is expected to provide ecological and renewable non-carbon energy sources to power rail and transit lines electrically, and would thus reduce energy cost and help lower pollution. Hydrogen fuel cells can find potential application in hybrid rail vehicles. Hydrogen fuel cells are expected to replace diesel engines and generators used in current diesel-electric trains, by using energy generated by the fuel cells, which is stored in batteries and is constantly recharged as the engine moves.
Driverless passenger trains, which includes the automated systems, are in operation in Copenhagen, Paris, Singapore, and Dubai. Automated systems enhance the running time of trains and escalate the average speed of the system.
The Dubai Metro is the longest driverless metro network in the world, covering 75 km. The Copenhagen Metro was the first to feature a fully automated system, including depot operation and launching, which operates 24 hours a day.