One of the less well publicized great advances of the past decade is that we have essentially solved desalinization.
Recent advances in the reverse osmosis process mean that capital costs for desalinization capacity have been driven low enough that they can be economically powered by off-peak intermittent power, essentially using reservoirs of fresh water as a grid battery of sorts. The cost of solar and wind in the places that need fresh water are low enough that this can economically replace natural fresh water even in middle-income countries.
Large-scale buildouts are ongoing. We will not need "extreme water recycling" to provide anyone with sufficient water.
Not that it's a bad idea anyway, because it's good for the environment to recycle the other stuff that you pull out of the wastewater stream.
I think that's still very power-hungry and only makes sense in rich, dry countries like Saudi Arabia. My dream is for the weekend to get on board with nuclear desalination (either fixed as part of a land-baded power plant or ship-based).
Israel desalination plant profitably offering a fixed price of 1.45 NIS per cubic meter. At current exchange rates that is around 0.40$ per cubic meter (1000L).
So, even if we replaced all freshwater use in the US with desalinated water at current prices it would only incur a additional cost of ~600$ per capita per year. If our water use were more similar to peer countrys such as Germany (410 m^3), France (475 m^3), Australia (724 m^3), or Japan (640 m^3) the per capita costs would only be ~150$-250$ per year.
What sorts of advances? Anecdotally, I've developed a bit of an interest in hydroponics (the progress of LED lighting makes growing niche vegetables indoors interesting to me) and I was pricing out RO systems which seemed much cheaper than I remember.
Dwarf Romaine Lettuce and many other leafy greens, Carolina Reapers, Habanadas, and hopefully other capsicum varieties if it goes well. Wasabi would be really interesting but seems pretty tricky.
In the end someone has to pay that cost anyway. Overbuild your intermittent sources (and then throttle them when there's oversupply), invest in baseload power (e.g. nuclear), keep using fossil fuels (and pay the environmental/health cost), build storage or curb demand (the case you mention).
Question really then becomes how much does it cost to over provision for 100% or 200%. Allowing to run 12h or 8h for the needed daily capacity.
There is certain fixed costs for facility and then adding capacity increases on top of that. But question is really by how much? 10-50% for 200% or 300% capacity might be acceptable if that sum is saved in energy costs.
One of the less well publicized great advances of the past decade is that we have essentially solved desalinization.
Recent advances in the reverse osmosis process mean that capital costs for desalinization capacity have been driven low enough that they can be economically powered by off-peak intermittent power, essentially using reservoirs of fresh water as a grid battery of sorts. The cost of solar and wind in the places that need fresh water are low enough that this can economically replace natural fresh water even in middle-income countries.
Large-scale buildouts are ongoing. We will not need "extreme water recycling" to provide anyone with sufficient water.
Not that it's a bad idea anyway, because it's good for the environment to recycle the other stuff that you pull out of the wastewater stream.