"Hydrogen is an increasingly popular energy carrier. It can be readily produced from water using renewable electricity, and it burns without any greenhouse gas emissions"
https://www.cummins.com/news/2022/01/26/how-do-hydrogen-engines-work
"electrolysis and creating hydrogen/oxygen gas"
http://waterpoweredcar.com/
"An alternator pulley is a device that allows a vehicle's alternator to be turned by a belt"
"The alternator pulley is sized to avoid over-driving the alternator when the vehicle is operating at highway speeds, while still providing enough speed to produce ample energy to maintain the battery's charge"
https://www.wikimotors.org/what-is-an-alternator-pulley.htm
"The alternator charges your battery by creating a voltage that is slightly higher than the voltage in the battery, causing a current to flow into the battery until it reaches the higher voltage."
https://www.standardbatteryinc.com/how-does-an-alternator-charge-a-battery/