3 ms·

>...which produces green fuel with a solar-to-hydrogen efficiency of 0.13 ± 0.03% and 0.95 kg m−2 h−1 of water vapour as the feed for the PC and collectable pur

>...which produces green fuel with a solar-to-hydrogen efficiency of 0.13 ± 0.03% and 0.95 kg m−2 h−1 of water vapour as the feed for the PC and collectable purified water. This integrated system maintains operational stability in seawater and other aqueous waste streams for over 154 h due to the isolation of the PC from contaminants in the liquid feedstock. So, wildly inefficient, but if the device is cheap enough to produce, could still be worthwhile where there are no other options. I know there is some interest in floating solar panels, which would probably be significantly more efficient (can centralize the hydrogen/H2O production at a large scale facility), but that struck me as introducing a host of engineering problems vs finding some unused land.

Terr_ 3y ago
Or to put it another way, "thermodynamic efficiency" or "reaction efficiency" are not the same as "economic efficiency." If the last is great--and we don't have unpriced externalities like pollution--then the first two aren't deal-breakers.
- pyrale 3y ago
  > If the last is great--and we don't have unpriced externalities like pollution--then the first two aren't deal-breakers. The first two are a major part of the last, though. That's why people are sceptic when this kind of news comes up.
taneq 3y ago
We're not short on sunlit ocean, we're short on energy and clean water. $/watt and $/liter are the relevant constraints, not kW/m^2.
- jillesvangurp 3y ago
  Exactly. It's manufacturing + installation + maintenance + infrastructure cost that define what this costs. I'm guessing these would need quite a bit of maintenance and attention. Things get dirty, hoses get blocked, etc. And of course reservoirs for fuel and clean water fill up. You are not going to put these in the middle of the ocean probably. This looks like it is designed for small scale usage close to where people live.

Terr_ 3y ago

Or to put it another way, "thermodynamic efficiency" or "reaction efficiency" are not the same as "economic efficiency." If the last is great--and we don't have unpriced externalities like pollution--then the first two aren't deal-breakers.

pyrale 3y ago
> If the last is great--and we don't have unpriced externalities like pollution--then the first two aren't deal-breakers. The first two are a major part of the last, though. That's why people are sceptic when this kind of news comes up.

taneq 3y ago

We're not short on sunlit ocean, we're short on energy and clean water. $/watt and $/liter are the relevant constraints, not kW/m^2.

jillesvangurp 3y ago
Exactly. It's manufacturing + installation + maintenance + infrastructure cost that define what this costs. I'm guessing these would need quite a bit of maintenance and attention. Things get dirty, hoses get blocked, etc. And of course reservoirs for fuel and clean water fill up. You are not going to put these in the middle of the ocean probably. This looks like it is designed for small scale usage close to where people live.