The following submission statement was provided by /u/Realistic-Plant3957:

However, a new study by researchers from Cambridge University has warned that green hydrogen production processes may not be as sustainable as initially believed.

Please reply to OP's comment here: https://old.reddit.com/r/Futurology/comments/zz1fxq/green_hydrogen_not_the_fuel_of_the_future/j28u7w2/