why isn’t it feasible to use wind or solar power (clean power) to run desalination plants to solve water crisis?



why isn’t it feasible to use wind or solar power (clean power) to run desalination plants to solve water crisis?

In: Technology

Its not profitable. Solar and wind produce a power output over a year that looks more like noise than constant power. So you can’t really calculate with that let alone run a profitable business. Sure it’s technically possible but nobody will do it because you can’t really make money with it. For a steady clean water output you will need a steady power supply.

Basically money. Desalination requires a lot of equipment and energy to run on a large scale, and solar panels/ wind farms (if the latter is even practical in the area in question) tend to get very expensive.

Other than really wealthy economies with some urban concentrated population (near a sea/ocean), it just gets too expensive. Desalination is energy intensive and water is heavy so moving it around in large volume is also energy intensive.

So while it is technically feasible, it is economically impossible to desalinate water for large scale low value agricultural purposes (for example). The water crisis tends to have a big impact on agricultural populations (low income to begin with so adds less value to the economy) rather than urban centers (higher productivity, wealth and can afford to pay more for water)

We will see it more and more in the future. Especially solar power has become cheaper than coal in most places and it combines favorably with desalination, as it can be easily regulated up and down. Sun > produces water, no sun > wait.

Perth Australia does it with wind power. [Cockburn Sound](https://en.wikipedia.org/wiki/Perth_Seawater_Desalination_Plant)

Tidal could doable if there is good enough tidal range?
This power should be reliable?

An ELI5 answer: its the same reason you need a big battery to power something big, rather than using a bunch of tiny ones taped together. Solar and wind power just arent big enough batteries to run desalination, at least not effectively

On a similar note, if the nuclear energy was used would it just be contaminated with radiation?

Desalination uses lots of power. Wind and solar power generate little power.

BUT, in a way, solar can be used, but by using the heat of the sun to evaporate water, thus separating salt from water. It’s pretty slow, though, so in most cases, it’s used to get to the salt, rather than to get the fresh water.

So, the problem isn’t if it’s possible or not, it’s possible. The problem is a matter of scale, you can’t scale it to the industrial scale needed to be meaningful.