It usually makes more sense to pump water to a nearby reservoir uphill. That water can be released back through turbines when solar production is lower - pumped hydro are basically giant batteries. So not so much pumping it back upstream, but a similar idea, just without expensive desalination.
Not a saltwater coast, but the Ludington plant on Lake Michigan is a good example of this: https://en.wikipedia.org/wiki/Ludington_Pumped_Storage_Power_Plant
I think they’re more asking about getting usable water than energy storage
Why not both?
You would also need to find a suitable location. If the reservoir is really far away, you’ll be losing too much energy. Think of transmission losses, but for water in a pipe. The reservoir would need to be pretty high as well, so a flat desert won’t work for an application like this.
Ideally, you would have a solar farm in the desert and use the excess energy to pump salt water to the top of a small mountain that sits right next to the ocean. With this setup, you would have a stable source of energy, which you could send to the grid. When the reservoir is full and energy demand is low, you could dump the remaining energy into desalination.
You could also use some of that energy to produce hydrogen and oxygen from water. During peak demand hours you could used a fuel cell to make electricity from the hydrogen.
You’ll also get oxygen as a byproduct, which could be used for a bunch of different chemical processes to get some additional revenue. This is basically a blueprint for a large industrial facility.
gotta do something with the brine
We are talking about humanity here, we will pump the brine into tapped out oil and gas holes and end up salting the aquifers.
Brine can be transported to different parts of the ocean? It’s a massive bodie of water. Widespread adoption would have to be massive as well to see significant increases in molar concentration.
Salinity doesn’t really work like that. You can’t just dump a bunch of brine and expect it to just mix with the rest of the seawater. A lot of that depends on temperature, currents, etc. You might just end up forming a brine lake in the ocean if the brine just so happens to end up at the bottom without ever mixing. Not to mention brine isn’t always just concentrated salt and water. It can include byproducts from desalination.
Reference:
People have made the argument for dumping nuclear waste in the ocean. I believe adding brine to existing brine resivours won’t be too much of a hassle.
Are there any brine reservoir in the ocean? That doesn’t seem to be a thing. It either mixes properly with the ocean if proper mechanisms are set or it just ends up sinking to the bottom of the ocean and killing everything there.
There’s storage inland, but that also has its own problems.
Nuclear waste in the ocean follows a similar idea (although larger in scope). You can’t just dump it and be done. You have to create a plan to slowly release it (over decades) to (hopefully) not adversely affect life
Those are the exact brine lakes I talked about that exist in the bottom of the ocean.
Brine is too dense to be above seawater. They accumulate in the bottom, creating essentially small pockets that kills almost every normal life. Only extremophiles live near it, and even then its usually just surrounding the edges of the lake.
You also can’t exactly guarantee that the brine you make ends up here. They are in the bottom of the ocean, not exactly a place you can pump brine to.
I don’t think you understand the scale and scope of modern engineering.
where exactly? what do you want to kill and pollute? what area deserves it?
Land acquisition cost and not in my backyard’ers. At least here in Southern California. There is no chance that a loosely regulated and toxic high salinity waste water plant would get past public and environmental scrutiny. The only really viable areas are the last local refuges for many.
Like from Mexico to Santa Barbara, the camp Pendleton Marine Corps base is one of the only viable spots. The decommissioned nuclear power plant would be one of the mostly likely spots to build such a facility, but that is surrounded by a state park and some of the most prised undeveloped local surf real estate. Many municipal and commercial projects have vied for that land, but there is fierce local opposition from a wealthy and very politically well connected public.
There has been occasional talk about opening up the Pacific side of the 5 freeway to public development as this is some of the federal government’s most valuable real estate. Even if this happened, that would become one of the most elite places to live in the country.
Few people know this, but the Southern California coast around Orange County and North of San Diego is a spot of rare deep ocean upwelling. There is a micro climate here within a couple miles of the coast that is regulated by the ocean upwelling maintaining temperatures. It is always cooler in the summer and warmer in the winter here and almost always between 50°F and 80°F even when a few miles away it can be 40°F-100°F. This is one of the main reasons why real estate in these areas is so high.
Any question like this can always be answered by asking yourself, who would profit from this?
