| Water in Southern California is a complex issue that isn't given its proper due - and desalination plants aren't the cure-all that people assume. Desalination plants: are expensive to build; are more energetically expensive than most alternatives, which means they are also more expensive to run (its tough to take salt out of water); inefficient - compared to alternatives, more water must be processed to create the same amount of potable water; environmental concerns, from intake (water intake may also 'suck in' krill, young fish, etc. which form the bottom of the food chain) and what happens with all of the concentrated 'sludge'? Dumping it back into the ocean would surely increase salinity in the area creating dead zones; time consuming to build - more water is needed now, not 10 years from now. In L.A. specifically, there are treatment plants like Hyperion which perform secondary treatment on waste-water and then pumps that treated water 4.5 miles into the ocean. Does it make sense to treat waste-water, pump it into the ocean so it picks up solutes like salt, then desalinate it so that it's potable and then pump it back to shore? It makes more sense to upgrade facilities so they can perform tertiary treatment to make waste-water potable - it'd be cheaper than desalination, and much of the infrastructure is already there. Also in L.A., storm runoff gets directed into a pipe system completely separate from the sewer system, so after a rainfall all of the water gets collected and essentially directed straight to the ocean via the stormdrain system without any treatment (and it also picks up massive amounts of debris and pollution along the way). It would also make sense to treat and store that kind of run-off instead of letting it go to waste (and pollute the beaches as well). Israel is often given as a shining example of desalination, but they also recycle something over 80% of their water for irrigation. Essentially, they used all alternatives before adding desalination. L.A. imports over 80% of its water, and only recycles ~2% of it. |
Ram pumps can pump water to a higher location that the water source without any added energy. The kinetic energy of the moving water is all that is needed. The waves supply the kinetic energy.
Once water is pumped into a water tower, then have a bunch of mirrors point at the tower to heat it up. Steam evaporates and flows down to a lower location.
Seems like once it is set up it would be completely stand alone without any electricity being needed. Not sure what kind of output it could generate or how efficient it is, but it wouldn't require any man-made energy.