# New-B needs help with portable solar



## cladano (Feb 3, 2011)

Please help me help me build a portable solar generator. :bow: And please excuse my ignorance.
I'm trying to build a portable solar backup generator to power this Atmospheric Water Generator (http://www.ecoloblue.com/ecoloblue30) which appears to have a 280 watt power intake. The backup solar/AWG would be used at home in case of power failure and also would be taken camping too.

I would like this system to be under $2000. I believe I need 2 solar panels, controller/fuse box, Inverter, and batteries but I have no clue what to look for.

Solar Panels: I'm guessing I would need 2 150/160 watt panels. I have no idea what would be a good solar panel ????

Controller: Not sure what to look for in a controller setup. I did find this one online but have no clue if it would work (http://www.solarpanelstore.com/solar-power.small-charge-controllers.sunsaver.morningstar_sunsaver_duo.info.1.html)

Inverter: It's my understanding that a pure sine inverter is best. I read a forum that mentioned this one (http://www.hodgesmarine.com/Xantrex-Prowatt-Sw2000-2000w-True-Sinewave-Inverte-p/xan806-1220.htm)

Batteries: This is probably the most confusing to me. I think I would need 2 batteries but not sure??? I see so many options here and have no idea what to look for...... AH?? No clue on what to look for or where to find some good cheap batteries.


Thank you so much for your time!
Dano


----------



## cmcon=7 (Mar 7, 2010)

I have done some experiments with dehumidification,, the trick is to keep the air flow/temp below the dew point.
you may do just as well with a cheap chest freezer with good air flow management to remove moisture from the air, or a radiant moisture collector for night time collection.
you do not necessarily need power to get water from the dessert.


----------



## dtsh (Feb 10, 2011)

I think the first thing you need to do is figure out how much wattage your dehumidifier uses in a 24 hour period of normal use. Probably the easiest way would be with a Kill-A-Watt, which are fairly inexpensive. Once you know how much power it draws per day, you can begin to calculate your minimums.

Figure out home many hours of insolation are available in the areas you expect to use your panels.
http://www.nrel.gov/gis/solar.html

Time of year matters greatly. Let's say you're in Ohio. In January there can be as little as 2 hours of insolation whereas in July there's 6 hours. To provide the same load all year requires 3 times as much wattage in the winter vs summer due to the changing angle of the sun and length of day/night.

Hope that helps you get started.


----------



## Jim-mi (May 15, 2002)

You can not use the words "good" and "cheap" in the same sentence when talking about batterys.

Its either--or


----------



## cladano (Feb 3, 2011)

I've already purchased this unit (hasn't arrived yet) so switching to something else is not an option at this point. This isn't for dehumidifier, it's for creating clean water in case water can't be pumped to my house for some reason and potentially for taking it camping.

When it arrives I'll hook it up to a Kill-A-Watt to find out it's average daily consumption.

Any suggestions on parts or retailers?

Thanks,
Dano


----------



## wy_white_wolf (Oct 14, 2004)

It would be best if you could hook it up to a kill-a-watt and measure it's power usage for a week to get an accurate power usage.

But here it goes, If your 280 watts is correct then:

Multiply that times the number of hours to run in a day

280W * 24Hours = 6720WH used in a day

Now you need to figure out how much you need to produce in a day with system losses

6720KH * 1.5 (66%) = 10,080WH we'll just round this off to an even 10KWH or about $1.20 worth of power off the grid.

Now we can figure out array size if I new your location. For off-grid you need to use worst case. Which would be the lowest daialy average for any month. National yearly daily average is @4.5, the worst case month usually end up between 1 to 3 hours. We'll use 2 since I don't know your location.

10KWH / 2Hours = 5000Watt array. 

That's way more than the 1 or 2 panels you were thinking about and would end up abot 10X-20X the cost you mentioned you wanted to keep it under. See why at first I suggested the KIll-a-watt and running it for a week.

Now the battery bank, you need more than 1 days storage so when you have a cloudy day you have power to get you through. You also need to run on only the top end of the Batteries to keep from abusing them.

Usually I just you the 5 days atonomy calculations and that really means that in 2.5 days you will have drained them to 50% SOC. That's about as low as you want top go. Then you want to divide that number by the battery bank voltage to determine bank size.

10000WH * 5 / 12 = [email protected]
/ 24 = [email protected]
/ 48 = [email protected]
Just for visual reference. That is about equal to 100-120 normal car sized batteries. See my opening statement again.


Yes sine wave inverters are easier on motors. bu8t with only a 280w load why get a 2000w one. Ovwersizing it that much really increases you power losses. (Generally) Inverters are most efficient when ran close or just under there rated power. Find one in the 300-500W range with a peak of about 450-750W.

WWW


----------



## cladano (Feb 3, 2011)

wy_white_wolf said:


> Yes sine wave inverters are easier on motors. bu8t with only a 280w load why get a 2000w one. Ovwersizing it that much really increases you power losses. (Generally) Inverters are most efficient when ran close or just under there rated power. Find one in the 300-500W range with a peak of about 450-750W.
> 
> WWW


Great point. Maybe something like this would be a better fit http://www.hodgesmarine.com/Xantrex-Prowatt-Sw600-600-Watt-True-Sinewave-Inver-p/xan806-1206.htm

Any suggestions on a kill-a-watt meter? I'm sure the water generator would only run long enough to fill the reservoir then shut off (or I would shut it off).


----------



## Harry Chickpea (Dec 19, 2008)

Read WWW's post again, especially the section about the number of batteries you would need.

FWIW, I wouldn't even attempt what you are trying to do. If I needed to get water out of the air in an emergency situation, I'd use calcium chloride as an absorbent, then heat the brine in a distiller to extract the water and recharge the brine. The device you bought is fine for use as a water cooler where you don't need to buy or lug the water, but is really not suitable for camping or power-less situations.


----------



## cladano (Feb 3, 2011)

Harry Chickpea said:


> If I needed to get water out of the air in an emergency situation, I'd use calcium chloride as an absorbent, then heat the brine in a distiller to extract the water and recharge the brine.


I'm certain the unit is what I want. It's going to run in my finished basement where it will provide clean water and to a small extent also act as a dehumidifier. Taking it camping would be a bonus but not it's intended purpose. I'm just wanting to make sure that there would be electricity so it will provide water in a "---- hit the fan" scenario. I'm a big believer in clean water and I may also purchase a Berkey gravity fed water filter down the road too. But for now I just want a simple solar setup so this can run (even part time) in a SHTF event.
Thanks for all the info so far :clap: Like I said, I'm very new to all this.


----------



## Jim-mi (May 15, 2002)

What all these posts are trying to say is that there is no "simple solar setup" for something that sucks up a lot of power/energy.

I'll bet that this unit needs to 'run' many many hours a day to get any usable amount of water . . . .
There fore just a "simple" solar panel running for 3-4 hours (?) of sunlight will not accomplish what you want.

What a world of difference there is in like Arizona . .single digit humidity vers up here in Mich with high humidity...........
Equating that to the "run time" for . .a glass of water.....

so go ahead and run that gizmo thru a kill-a-watt meter in your "basement" and let us know some results.........
One quart of h2o for how many watt hours.......??

I'm not knocking those things . . I've seen the advertizing for them and have wondered about their performance . . .?????


----------



## byexample (Aug 28, 2009)

I can see condensing water out of the fresh air for clean drinking water... but I'd be fairly dubious about the idea of harvesting water out of my basement. Seems like there are all sorts of potential contaminants in basement air that could be retained in any harvested water. Mold, radon, out-gassing of construction materials, etc.. 

As far as power goes it might not be as bad as some suggest. If one were to look at the power draw of a refrigerator and assume it was going to draw that amount of power continuously you'd calculate an enormous sum of energy. Thankfully refrigerators don't run their compressors continuously.

I expect that a fair portion of the power that your water harvesting gizmo draws is used for some sort of cooling effect. That portion of the system may not run continuously -- much like a refrigerator.

As many have suggested, run this unit for a week or so and log the daily power consumption AND the quantity of water that you were able to harvest. Then you'll know how much power you need and you'll be able to compute an energy cost per gallon of water as well.

Best of luck! Please shared with us your results.


----------



## mightybooboo (Feb 10, 2004)

IMO get the 2000 watt inverter.It will give much more versatility in future vrs bleeding edge energy savings in the here and now IMO.So the de- humidifier doesnt work out,what else might you use that system for,a freezer or ?????

Bleeding edge is expensive. Like a fighter plane the last 15% in wow factor comes at a huge increase in cost.


----------



## mightybooboo (Feb 10, 2004)

cladano said:


> I'm a big believer in clean water and I may also purchase a Berkey gravity fed water filter down the road too.


Purchase that or an American made aqua rain or make your own now.Not later.

http://www.alpharubicon.com/kids/homemadeberkeydaire.htm
I made one of these,but I would do it even better,use 3 buckets,top one the particulate filter,2nd one the charcoal filter and 3rd to collect the water.Currently Im using the berkey black filter,2 bucket system.

I like my aquarain a lot too (stainless steel the best IMO),just wanted to build one because I wanted to prove the concept in my own use,they work very well.I used an old coffee style machine like a Lodge or Business might have so costs was pretty much filter and not much else. I think plastic makes a cleaner setup,no scale like my aluminum does,but you decide if plastic is OK for your drinking water.


----------



## mightybooboo (Feb 10, 2004)

New thread


----------



## cladano (Feb 3, 2011)

byexample said:


> I can see condensing water out of the fresh air for clean drinking water... but I'd be fairly dubious about the idea of harvesting water out of my basement. Seems like there are all sorts of potential contaminants in basement air that could be retained in any harvested water. Mold, radon, out-gassing of construction materials, etc..


This unit has a few filters that should weed any contaminates out. I don't know for sure but I'm guessing it's a lot better to pass those things threw your gut than breathing them in. My basement is also less than 6 yrs old so I'm hoping mold/radon isn't as big an issue as it is in some older basements.

I'm also assuming this unit wouldn't run continually. 

I just received the kill-a-watt meter so I'm hoping to have some hard numbers very soon.

:rock:


----------

