Comment by bombcar
3 days ago
I wonder at what point the up-front costs of massive desalination would overcome the (often hidden and externalized) costs of projects like this.
3 days ago
I wonder at what point the up-front costs of massive desalination would overcome the (often hidden and externalized) costs of projects like this.
> the up-front costs of massive desalination
Desalination is dominated by operating costs.
Correct it's massively energy intensive to filter the salt out the newest best ideas still use ~2 KWh/m3 of water and that's a lab system in perdue that batches the process instead of having it run continuously which is why current RO desalination systems require so much energy.
For a real world comparison, the Perth desalination plant claims ~4kWh/m3.
California pays other states to take its excess solar energy. Power for a project like this isn't the issue, actually building the system is the issue.
5 replies →
> it's massively energy intensive to filter the salt out the newest best ideas still use ~2 KWh/m3 of water
Am I alone in thinking that doesn't sound like a lot? That would be something on the order of 10% of what major cities charge for tap water?
A scaled down perspective is….
The most efficient commercial desalinator for boats is 32 Watts a gallon.
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As long as we don't try to hide and externalize the cost of all the hyper-saline brine management that comes with desalination.
We can store it in the remains of Owens Lake ;)
I don’t think the brine pollutant issue has been meaningfully solved. You are also now pumping water inland uphill the whole way.
For usage where the water mostly returns as sewage, is treated and then returned to the ocean, you can just dilute the brine with the treated discharge and then it returns at basically the original salinity.
It is common now for treated discharge to be sent to a discharge lake/leach wetlands so it can be used to replenish groundwater supplies.