4 ms·

Yes, exactly this. These membranes will foul and need replacing. I don’t see why anyone would use this over freshwater. There’s plenty of freshwater available i

by eloff 4y ago

Yes, exactly this. These membranes will foul and need replacing. I don’t see why anyone would use this over freshwater. There’s plenty of freshwater available in many places. It literally runs into the ocean. You just don’t build one of these plants in the desert. It might be interesting in niche cases - desert countries where they're already producing water via desalination. But those countries tend to produce energy from fossil fuels anyway, and it's less effective to burn fossil fuels to split water than it is to just split methane to begin with. Maybe in the far future.

jjk166 4y ago
> You just don’t build one of these plants in the desert. If you're generating the electricity in a big solar field which would ideally be built in a desert (few clouds, cheap land) then building the electrolysis plant nearby makes sense. There are lots of areas like north Africa, western Australia, the southwest of North America, the Arabian peninsula, etc where sunlight and sea water are readily available but fresh water is at a premium. Ultra high voltage DC makes power transmission over continental scales technically possible, but the losses are still significant, having the option to use power close to where it is produced enables a lot of possibilities.
- eloff 4y ago
  In Arabia and North Africa it makes more sense to use the solar to displace fossil fuel derived energy than to produce hydrogen - again if you want hydrogen and you’re burning fossil fuels for electricity it makes no sense to use the electricity to get the hydrogen - use methane and cut out the middleman. There might be some places where this could work, but they do seem quite niche.
  - jjk166 4y ago
    You can both provide power locally (if needed - the desert regions with little rain and cheap land tend to have minimal population) and also produce hydrogen with excess power, which could be exported to other locations, used locally as an alternative to other energy storage methods like batteries, and for various things which are not trivially electrified like industrial process heat or vehicle fuel. No one here is arguing that fossil fuels should be burned to conserve solar energy for other uses.
    - eloff 4y ago
      Excess power would have to be very sporadic, too sporadic to offset fossil fuel generation - in which case it’s too sporadic to justify capital expenditure for electrolysis and hydrogen production. I just don’t see it.

by eloff 4y ago

jjk166 4y ago

> You just don’t build one of these plants in the desert. If you're generating the electricity in a big solar field which would ideally be built in a desert (few clouds, cheap land) then building the electrolysis plant nearby makes sense. There are lots of areas like north Africa, western Australia, the southwest of North America, the Arabian peninsula, etc where sunlight and sea water are readily available but fresh water is at a premium. Ultra high voltage DC makes power transmission over continental scales technically possible, but the losses are still significant, having the option to use power close to where it is produced enables a lot of possibilities.

eloff 4y ago
In Arabia and North Africa it makes more sense to use the solar to displace fossil fuel derived energy than to produce hydrogen - again if you want hydrogen and you’re burning fossil fuels for electricity it makes no sense to use the electricity to get the hydrogen - use methane and cut out the middleman. There might be some places where this could work, but they do seem quite niche.
- jjk166 4y ago
  You can both provide power locally (if needed - the desert regions with little rain and cheap land tend to have minimal population) and also produce hydrogen with excess power, which could be exported to other locations, used locally as an alternative to other energy storage methods like batteries, and for various things which are not trivially electrified like industrial process heat or vehicle fuel. No one here is arguing that fossil fuels should be burned to conserve solar energy for other uses.
  - eloff 4y ago
    Excess power would have to be very sporadic, too sporadic to offset fossil fuel generation - in which case it’s too sporadic to justify capital expenditure for electrolysis and hydrogen production. I just don’t see it.