3 ms·

Very tough problem and likely not possible. Look at energy requirements of desal vs. fresh water pollution proliferation. 10-14 kwh required to desal 1000 gal

Very tough problem and likely not possible. Look at energy requirements of desal vs. fresh water pollution proliferation. 10-14 kwh required to desal 1000 gallons of water. 50% of world's food supply is powered by proliferation of phosphorus and nitrogen rich fertilizer and their corresponding runoff.

bagels 4y ago
That puts the cost on par with current residential water rates in the bay area.
martin_a 4y ago
> 10-14 kwh required to desal 1000 gallons of water. Wait, are those numbers right? That doesn't look that expensive to me. That's a roof full of solar for lots of water per day?!
- Mistletoe 4y ago
  Surely that isn’t right. My little 12x10 foot greenhouse uses 5kwh on a cold night to stay above freezing using a little 800 watt space heater that cycles off and on. Edit: nope I checked and that is a correct number.
  - martin_a 4y ago
    Wow, I really thought desalination would be something like factor 10 more energy expensive. Regarding your greenhouse: Does it sit flat on the earth? I'm thinking about lowering the greenhouse at my parents house somewhat into the earth, I think 2 feet would already help with keeping it warmer...
    - Mistletoe 4y ago
      No it just sits on the ground. I went down a whole rabbit hole recently about how to keep a greenhouse warm in winter. Being below ground would probably help somewhat. A lot of people do something like this- https://ceresgs.com/environmental-controls/gaht/ https://ceresgs.com/environmental-controls/gaht/ I did the math and used a kill a watt to monitor the usage and just doing a little space heater hooked to an Inkbird temperature controller was plenty economical for me. I have cheap electricity where I live though. About 30 cents a night when it is freezing outside. So absolutely worst case scenario would be $9 a month which I can handle for how much joy it gives me to be able to grow plants in the winter.
      - martin_a 4y ago
        Wow, that's sure another level of tech with the ground heater. Not sure if you can DIY that thing... Sounds great with your energy prices. At that rates, I'd go for electric heating, too. :-D

bagels 4y ago

That puts the cost on par with current residential water rates in the bay area.

martin_a 4y ago

> 10-14 kwh required to desal 1000 gallons of water. Wait, are those numbers right? That doesn't look that expensive to me. That's a roof full of solar for lots of water per day?!

Mistletoe 4y ago
Surely that isn’t right. My little 12x10 foot greenhouse uses 5kwh on a cold night to stay above freezing using a little 800 watt space heater that cycles off and on. Edit: nope I checked and that is a correct number.
- martin_a 4y ago
  Wow, I really thought desalination would be something like factor 10 more energy expensive. Regarding your greenhouse: Does it sit flat on the earth? I'm thinking about lowering the greenhouse at my parents house somewhat into the earth, I think 2 feet would already help with keeping it warmer...
  - Mistletoe 4y ago
    No it just sits on the ground. I went down a whole rabbit hole recently about how to keep a greenhouse warm in winter. Being below ground would probably help somewhat. A lot of people do something like this- https://ceresgs.com/environmental-controls/gaht/ https://ceresgs.com/environmental-controls/gaht/ I did the math and used a kill a watt to monitor the usage and just doing a little space heater hooked to an Inkbird temperature controller was plenty economical for me. I have cheap electricity where I live though. About 30 cents a night when it is freezing outside. So absolutely worst case scenario would be $9 a month which I can handle for how much joy it gives me to be able to grow plants in the winter.
    - martin_a 4y ago
      Wow, that's sure another level of tech with the ground heater. Not sure if you can DIY that thing... Sounds great with your energy prices. At that rates, I'd go for electric heating, too. :-D