5 ms·
Absolutely, but it's a scale problem. Say you want to produce 1000m3 a day. Well you can build a small plant that makes 41m3 ish an hour and run it 24/7. If you
by 10u152 3y ago
Absolutely, but it's a scale problem. Say you want to produce 1000m3 a day. Well you can build a small plant that makes 41m3 ish an hour and run it 24/7. If you want to produce 1000m3 a day in the three or four hours where solar energy is very cheap you need a plant that does 250m3 an hour - or about 5x the size. So your energy is cheaper but your capital cost is 5x or so.
- scythe 3y agoIf you save enough on energy, you can switch your system to save on capital. RO has a fancy nanostructured membrane but electrodialysis or MSF might be easier to build at the cost of 20-50% worse efficiency.
- gonzo41 3y agoIf you build a few batteries next to the plant and that problem is solved.
- 10u152 3y agoThat also increases capital costs, putting us back to square 1. Also, have a look at the energy requirements of desal plants. "a few batteries" is pretty gargantuan hand waving
- dimitar 3y agoOr you can build reservoirs for freshwater
- jvanderbot 3y agoVery much. Or pump it into aquifers.
- ehnto 3y agoMaybe the storage could be part of the energy solution, by pumping to an uphill resovior when power is cheap, and sending it through to downhill resoviors via a hydroplant during the peak hours.
- Maxion 3y agoI don't think there are very many places that pumped hydro can be built, where it hasn't been built. You also need quite the significant height difference for it to be meaningfull.
- 10u152 3y agoThat helps with storage on the output side. But what about the issues/capital costs/resource/labour usage of building huge capacity plant that only gets used 15% of the day?
- jvanderbot 3y agoI don't understand the question. Why can we only pump into aquifers 15% of the day? The point of having massive storage is that you can build a smaller plan and run it all day. But anyway, arguments about cost of making drinking water are moot. We need it, so eventually all options will be explored as needs increase.
- BobbyJo 3y agoIt is very likely that costs would scale sub-linearly. So that 5x is likely dramatically overestimating the increase in capital requirements.
- femto 3y agoMaybe it could be combined with pumped hydro? Pump the water to a higher elevation during daylight hours, then use the pressure of the elevated water to drive osmosis based desalination around the clock. You would have to build a reserviour, but it only has to be big enough to hold 24 hours worth of water. If there is not a high enough hill, some/all of the elevation difference can be in the form of a hole, such as an old mine.
- UnlockedSecrets 3y agoThe requirement for a large high-low point for pumped storage to be effective would limit it to a few areas wherein it could be viable. I imagine other energy storage technologies would be more viable.
- 10u152 3y agoThere's inherently no advantage to just taping the two things together. The idea is to make drinking water. Storing energy is a separate challenge. There's no advantage to combining the two.
- elmolino89 3y agoAssuming you use the sea water: in a hot climate if the reservoir is exposed evaporation will make the water more salty. Building covered elevated cisterns just for the salty water energy storage may be too costly compared to other options, not to mention the risk of creating a salty desert / contaminated aquifer in the case if it leaks out. Also desalinated water does not to be used the moment it is produced. One can run desalination facility at full blast during the day using renewable energy and at a lower or even trickling speed during the night using cheaper, often wasted otherwise energy from the grid.
- femto 3y ago> One can run desalination facility at full blast during the day The advantage is that you need a smaller desalination facility, as it can run at 100% duty cycle. Pumped hydroelectricity could do something similar, but why not have a go at removing the losses of converting back to electricity. (Then again, if you have an electric pump you already have most of the equipment required to produce hydroelectricity by running it in reverse, so pumped hydro might be better because it is more versatile?)