Not sure this is better than reverse osmosis... They mention ~15Wh/L @ 1L/hr... The Katadyn Powersurvivor 40 (pretty compact and 11kg) uses 8.5Wh/L @ 6L/hr...
https://www.spectrawatermakers.com/us/us/89650-8013438-Katad...
From seawater to drinking water, with the push of a button
71–80 of 103 posts
Re: From seawater to drinking water, with the push of a button
#72> requires only 20 watts of power per liter. So if you want a liter, you have to supply 20 watts. For how long? Forever? Does the water instantly become turbid when power is removed? Tsk, tsk, MIT. I would have thought an MIT journo would know what a watt is.
When someone uses watts as a unit of energy, they mean watt hours. It's very common.
Re: From seawater to drinking water, with the push of a button
#73> requires only 20 watts of power per liter. So if you want a liter, you have to supply 20 watts. For how long? Forever? Does the water instantly become turbid when power is removed? Tsk, tsk, MIT. I would have thought an MIT journo would know what a watt is.
When someone uses watts as a unit of energy, they mean watt hours. It's very common.
... and in the video they specify 20Wh/L.
Re: From seawater to drinking water, with the push of a button
#74Am I reading this wrong? It uses less energy at higher production rates? This is a verbatim copy of the text at 1:32 in their video: Seawater >> Drinking Water ~ 20Wh/L for 0.3L/h of production rate ~ 15Wh/L for 1.0L/h of production rate so it uses LESS energy to get MORE drinkable water per hour? That seems odd.
I assume this means with a larger device...
Re: From seawater to drinking water, with the push of a button
#75Earlier quoted context omitted.
The article says they can get 1 liter for every 20 watts. So that'd give them 17,597 ounces per kWh.
It does say that; and you've converted between watts and watt-hours. The article's claim doesn't make sense.
I feel like nobody watched the video (although I do wish the article text had been clearer).
The video specifically shows (at 1:34) that the machine operates at 15Wh/L (for the larger version, the smaller version is 20Wh/L).
This is 15Wh/33 oz (since we seem so set on using customary units), or 2200 oz per kWh.
Re: From seawater to drinking water, with the push of a button
#76Edit: I wrote out the comment below criticizing the efficiency of this device, when compared to reverse osmosis RO desalination (100x less efficient). However, they’re not trying to be more efficient than RO devices, they’re trying to be more compact, portable, and avoid the need for filters. They’re solving for a different problem than I was measuring them against. In my race to criticize, I overlooked those key det…
The video claims that the machine operates at 15Wh/L (for the larger version, the smaller version is 20Wh/L).
This is 15Wh/33 oz, or 2200 oz per kWh.
That's roughly one order of magnitude greater than your estimate.
Re: From seawater to drinking water, with the push of a button
#77Not sure this is better than reverse osmosis... They mention ~15Wh/L @ 1L/hr... The Katadyn Powersurvivor 40 (pretty compact and 11kg) uses 8.5Wh/L @ 6L/hr... https://www.spectrawatermakers.com/us/us/89650-8013438-Katad...
Once an RO filter gets clogged, it stops working.
Re: From seawater to drinking water, with the push of a button
#78Earlier quoted context omitted.
The problem is that southern California is trying to grow a shit-ton of crops that aren't suitable for the environment there. The almond industry is particularly guilty in this regard. Desalination will never scale to a level suitable to supply that industry. If anything they'll take that water and just grow even more crops, while still sucking the aquifer dry. Thing is, aquifers compact when you draw water from them…
> Desalination will never scale to a level suitable to supply that industry. Are you sure about that? It's simply a question of economics. As long fresh water from other sources is significantly cheaper, no one's going to invest in large scale desalination. Once this changes it becomes a question of which is more expensive - shutting down the agribusiness or running large scale desalination (which has options, from n…
It is true in California, because you need to dump the concentrated brine somewhere, and doing that at industrial scale will run up against environmental protections.
Re: From seawater to drinking water, with the push of a button
#79Am I reading this wrong? It uses less energy at higher production rates? This is a verbatim copy of the text at 1:32 in their video: Seawater >> Drinking Water ~ 20Wh/L for 0.3L/h of production rate ~ 15Wh/L for 1.0L/h of production rate so it uses LESS energy to get MORE drinkable water per hour? That seems odd.
I assume this means with a larger device...
Okay that makes sense
Re: From seawater to drinking water, with the push of a button
#80Earlier quoted context omitted.
I want to thank you for your edit, and for keeping the original text. Recognizing something you said ignored portions of the argument, changing the argument, and keeping the original portion to show _why_ you were wrong but still adds to the conversation is very valuable. I commend you for your ability to double guess yourself
Thank you. And you’re right, I am amazing ;) But seriously the main reason I write these comments is to work through my thoughts as I try to articulate them and get feedback on what I’m thinking. I’m actually happy when someone points out a mistake because I learned something. When I’m right, I haven’t gained anything. Sure, my ego enjoys the satisfaction of being right but my already inflated ego doesn’t need anymor…
My biggest issue is when I hit send on something when what it really needed was another editorial revision.