[blix]

Fukuoka's desalination plant treats about 16400 m^3 of water per day. Assuming 3kWh per m^3 of water, this works out to a time-averaged power consuption of ~2000kW.

The osmotic power plant generates about 100kW, so it's about 5% of the total desalination energy requirement.

[tempestn]

Ah, so a slightly more efficient desalination plant then.

[rrrrrrrrrrrryan]

Slightly more efficient, with less waste.

[mrexroad]

Pretty solid win-win

[sl-1]

Depends on the CAPEX and OPEX requirements. If it is cheap to do, it could be a solid win, but if the plant requires a lot of capital, it might be cheaper to just take the hit on efficiency

[azepoi]

Yes the brine could just be diluted wih gray water to reduce the environnemental impact without the energy recovery of the osmotic plant and the capital can be invested in other renewable with better efficiency.

That being said it's a first so it's a pilot project needed to have feedback on a real plant in operation and not just back of the enveloppe calculations and suppositions. Sometime you need to just build the thing to encounter problems, issues or non-issues.

[rileyphone]

According to this delightful overview [1] of the desalination plant, the capacity overall is 12000kW so that's definitely close enough.

1. https://www.niph.go.jp/soshiki/suido/pdf/h21JPUS/abstract/r9...

[wavemode]

Why are we assuming 3kWh per cubic meter of water?

[blix]

I did some cursory research and that seems to be a common estimate for modern osmosis-based desalination energy costs.

If you have a better estimate, feel free to supply it.