The problem with “from water” is that it takes as much energy to separate the hydrogen and oxygen in water as you get back by oxidizing the hydrogen to produce water. You can’t use water as a useful way to store hydrogen for energy because of that.
Good thing people have been able to use untreated ocean water as the feedstock. It looks like it needs to be scaled up, but the economic advantage should help incentivize that (seawater is free; treated water is expensive!).
Water Cycle 101:
The oceans are salty because rain water has been flushing salt downstream for billions of years. Salt also collects in endorheic basins such as the Great Salt Lake and Mono Lake, for the same reason. Rain clouds form primarily from evaporation of ocean water, which leaves behind slightly increased salinity, although its effect is widely geographically distributed.
There’s a difference between that distributed evaporation and the concentrated salinity increase of effluent from a reverse osmosis desalination plant or a hypothetical hydrogen plant, but the basic answer is yes, leave the salt in the ocean. It will be fine.
The problem with “from water” is that it takes as much energy to separate the hydrogen and oxygen in water as you get back by oxidizing the hydrogen to produce water. You can’t use water as a useful way to store hydrogen for energy because of that.
Also, that’s our drinking water you’re turning into fuel.
Good thing people have been able to use untreated ocean water as the feedstock. It looks like it needs to be scaled up, but the economic advantage should help incentivize that (seawater is free; treated water is expensive!).
Where do you store all that endless salt though? Or are you going to salinate the oceans further?
Water Cycle 101: The oceans are salty because rain water has been flushing salt downstream for billions of years. Salt also collects in endorheic basins such as the Great Salt Lake and Mono Lake, for the same reason. Rain clouds form primarily from evaporation of ocean water, which leaves behind slightly increased salinity, although its effect is widely geographically distributed.
There’s a difference between that distributed evaporation and the concentrated salinity increase of effluent from a reverse osmosis desalination plant or a hypothetical hydrogen plant, but the basic answer is yes, leave the salt in the ocean. It will be fine.