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From seawater to drinking water, with the push of a button

news.mit.edu

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Re: From seawater to drinking water, with the push of a button

#81

Post by BeefWellington »

qayxc wrote: post #67
BeefWellington wrote: post #65

Earlier quoted context omitted.

The wording in the article is specifically: > requires only 20 watts of power per liter. Whether the article is accurate or not I think you missed that.

The point is that 7W/hour is nonsensical. It's a non-unit and physically doesn't make sense in any context. The power is independent from the volume. Total energy use is volume dependent. 20 Watts per litre is mix of units that's nonsensical. Watt is Joules (Energy) per second (time), i.e. power. Either time is irrelevant, that is the device draws 20 Watts of power, in which case you can ditch the litre. Or the power…

Science reporting is not great but colloquially people use 20W per as a way of meaning Watt-hours.

If this is correct, they're saying it takes 20 watts (meaning Wh) to deliver a Litre of water, over three and a bit hours. The time is provided just obfuscated by their "we deliver 0.3L/hour" statement, so by saying 20W/L it does sort of make sense within the context.

~6W/hour (if it means we use a total of 6Wh) would be different than claiming the system runs off 0.1 Watts. Given the size of that solar panel, I suspect they're claiming they are using ~6 Watts for a period of one hour to produce 0.3L. Alternately, they're just flat out wrong and they're using 20 watts for one hour to produce 0.3L.

It could be worded better but I think this is what they're trying to say is that they're consuming 6W.

Re: From seawater to drinking water, with the push of a button

#82

Post by swader999 »

KennyBlanken wrote: post #29

If I had a dollar for every project MIT's press office has said will be revolutionary and end (insert major world health/water/resource/energy/food problem), I'd be a very, very rich person. I'm not sure why MIT's press office gets so much favor here, particularly given their/MIT's track record. Post articles by science journals and news outlets that will tell us if this is actually going to work or if it's just yet…

At least this instance has a workable demonstration. Looking at you battery tech...

Re: From seawater to drinking water, with the push of a button

#83

Post by MichaelApproved »

Damogran6 wrote: post #80
MichaelApproved wrote: post #34

Earlier quoted context omitted.

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.

I almost instantly hit the edit button after I post a comment.

Re: From seawater to drinking water, with the push of a button

#84

Post by nullc »

qayxc wrote: post #59
nullc wrote: post #3

So how is this distinguished from existing commercially available continuous electrodeionization?

Uses less power and is portable? That's pretty much all I could gather from the article.

That's its claimed advantages against reverse osmosis.

Re: From seawater to drinking water, with the push of a button

#85

Post by MichaelApproved »

zmgsabst wrote: post #38
MichaelApproved wrote: post #37

Earlier quoted context omitted.

OP here. Thanks for understanding what I’m trying to say and putting it in the correct terminology. However, I think I’d still make the same mistake in the future because I don’t understand how to express what the (assumed) 50 watt rated panel is generating over half an hour. If it’s running at 60% efficiency then it’s generating at 30 watts per hour. After an hour of running, we’ve accumulated 30 watts of energy. If…

This is what the other person was trying to say: “Watt” is the unit of power which is the rate of change in “joules”, which is the unit of energy . In the way that “velocity” is the rate of change in “position”. 1w = 1J/s A “watt-hour” is another way to represent joules/energy by integrating watts/power over time. 30 watts * 30 minutes = 15 watt- hours or 54 kJ. 30 miles/hour * 30 minutes = 15 miles or 24km > Does it…

Thanks. I’ll need to read that a few times because I struggle with this constantly.

Re: From seawater to drinking water, with the push of a button

#86

Post by zmgsabst »

MichaelApproved wrote: post #85
zmgsabst wrote: post #38

Earlier quoted context omitted.

This is what the other person was trying to say: “Watt” is the unit of power which is the rate of change in “joules”, which is the unit of energy . In the way that “velocity” is the rate of change in “position”. 1w = 1J/s A “watt-hour” is another way to represent joules/energy by integrating watts/power over time. 30 watts * 30 minutes = 15 watt- hours or 54 kJ. 30 miles/hour * 30 minutes = 15 miles or 24km > Does it…

Thanks. I’ll need to read that a few times because I struggle with this constantly.

I think part of the confusion is we don’t normally have units for rates of change.

So let’s create one: the “walk” is the speed a person can walk — 3mph.

Then I can say the store is “3 walk-hours away”, even if I normally drive the 9 miles with my car.

3 walk-hours = 3 hours @ 1 walk = 18 minutes @ 10 walk (or 30mph)

Batteries are rated in “watt-hours” for the same reason:

3wH = 3 hours @ 1 watt = 18 minutes @ 10 watt

Re: From seawater to drinking water, with the push of a button

#87

Post by sandworm101 »

>> The researchers also created a smartphone app that can control the unit wirelessly and report real-time data on power consumption and water salinity.

No no no no. I was all onboard with this seemingly wonderful product until I hit that line. The things that provide fresh water, that actually enable life functions, should NEVER involve controller aps. Switches. Dials. Positive on/off switches. Maybe the occasional touchscreen. But please do not put the need for a working/charged/connected cellphone between the user and their source of fresh water.

And they say that this thing uses about as much power as a cellphone charger. Wrong. It requires the power of a cellphone charger to filter water, plus a second charger to power the cellphone running the app.

Re: From seawater to drinking water, with the push of a button

#88

Post by joshuaheard »

sandworm101 wrote: post #87

>> The researchers also created a smartphone app that can control the unit wirelessly and report real-time data on power consumption and water salinity. No no no no. I was all onboard with this seemingly wonderful product until I hit that line. The things that provide fresh water, that actually enable life functions, should NEVER involve controller aps. Switches. Dials. Positive on/off switches. Maybe the occasional…

A cell phone app would be handy for remote monitoring and control. Say you lived a mile away from the ocean where it is deployed. You could turn it on and off depending on the tide and know when the container you are filling is full.

Having just completed a home remodel where all the home automation features have an app, having apps is a handy way to monitor and control your hardware without leaving your couch, or even if you are off-premises.

Re: From seawater to drinking water, with the push of a button

#89

Post by sandworm101 »

joshuaheard wrote: post #88
sandworm101 wrote: post #87

>> The researchers also created a smartphone app that can control the unit wirelessly and report real-time data on power consumption and water salinity. No no no no. I was all onboard with this seemingly wonderful product until I hit that line. The things that provide fresh water, that actually enable life functions, should NEVER involve controller aps. Switches. Dials. Positive on/off switches. Maybe the occasional…

A cell phone app would be handy for remote monitoring and control. Say you lived a mile away from the ocean where it is deployed. You could turn it on and off depending on the tide and know when the container you are filling is full. Having just completed a home remodel where all the home automation features have an app, having apps is a handy way to monitor and control your hardware without leaving your couch, or ev…

But does the pipe bringing fresh water into your house use an ap? There are things in this life that are expected to "just work", that are so basic they should not be trusted to aps. This product isn't for a fancy house in a city. It is a portable product meant for use in remote areas, by soldiers no less, far away from working cellphone towers or reliable power supplies. Serious consideration should be given before attaching anything more complicated than an on/off toggle switch.

Re: From seawater to drinking water, with the push of a button

#90

Post by xtracto »

sandworm101 wrote: post #89
joshuaheard wrote: post #88

Earlier quoted context omitted.

A cell phone app would be handy for remote monitoring and control. Say you lived a mile away from the ocean where it is deployed. You could turn it on and off depending on the tide and know when the container you are filling is full. Having just completed a home remodel where all the home automation features have an app, having apps is a handy way to monitor and control your hardware without leaving your couch, or ev…

But does the pipe bringing fresh water into your house use an ap? There are things in this life that are expected to "just work", that are so basic they should not be trusted to aps. This product isn't for a fancy house in a city. It is a portable product meant for use in remote areas, by soldiers no less, far away from working cellphone towers or reliable power supplies. Serious consideration should be given before…

Right, the more I learned about computers and automation, the more I want dumber stuff. Intelligent doorlock? Alexa lights? Ring? Nooo thank you, I don't want to be left out of my home or without light because of some internet error.

I like my electronics like my dogs: dumb as a mule.

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