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Living offgrid with small solar system(s)


George Harmony

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On 17/11/2016 at 9:07 PM, Muhendis said:

Further thoughts on Redflow:

I've had a read through the specs. and the installation manual for these batteries and here are my observations. 

The system works in a similar fashion to the vanadium flow battery. You pass a fluid through the cell and a current is generated from ionic transfer (simply put). In this case the fluid is zinc bromide and the zinc is the active component. The zinc is plated onto a plastic membrane during charge and back into solution during discharge. The battery is not sensitive to degradation due to partial charge and discharge and so is well suited to solar charging applications. At 240kg for the standard 200Ahr 48v battery it is not light, but that could also be said about lead acid batteries. Physically it is small enough for direct replacement of a 200Ahr 48v lead acid battery. It can be discharge to 100% and does not suffer any ill effects although the discharge rate is best at C5. The down side for me is it's efficiency. At 80% you have to ask where the other 20% is going. The answer to that is, it gets hot. 2.4Kw. In an ambient of 25 - 30 degrees that is not a problem and fan circulation will take care of it but my feeling is that at 40+ degrees a dedicated air conditioned and well ventilated environment is a must. Well ventilated is required because the thing can give off hydrogen if things go wrong. I don't yet know the cost of the battery but the cost for me of a special air conditioned enclosure would need to be added. There is also a quirky system that requires a regular self maintenance cycle and to do that a separate supply is needed because the battery will be disconnected from the electronic control system at that time.

Hi M.   it was a friend of mine who said "check out the Redflow battery".  On discovering how quirky (your words) and involved and also they don't seem to want to give a price, it seems all too hard despite all thy do have going for them.

Competition seems to hotting up in the battery world and unless something simple enters the field, lithium could be the winner at the moment. I could be wrong and often am.

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On 17/11/2016 at 11:42 AM, Muhendis said:

Hi Naam and Joe. Good to see you are still around.

 

I am still working on my DIY wind turbine but running a small farm tends to get in the way of other hobbies a bit. If anyone knows of a solar device for removing weeds please let me know. I have modified my ideas a bit and will be going for the VAWT design rather than the HAWT. Efficiency is not so good but my generator is a bit cumbersome and I would be nervous at having such a big weight high up on the end of a pole. The VAWT would also be easier from an assembly and maintenance point of view.  http://icewind.is/en/

 

I will be changing my FLA batteries some time soon. All the reasons not to go for the lead acid are coming back to haunt me.  I still have a large number of VRLA's in storage (pun intended). When the VRLA's become used up I am hoping some of the new technologies will have matured enough to be affordable. Redflow did not yet get a mention so I have had a quick look at the Redflow information and my initial thoughts are that it is an interesting system well suited to my application. 

 

Thanks for that Joe. I will be making further enquiries after I've done a bit more reading.

 

Naam I'm sorry you lost 20.7kg. Never mind. I expect if you look carefully you will find it again one day.

 

All of those low voltage ideas from George are very useful and are a practical solution for remote areas where a few lights and a fan are needed. 

Solar device for removing weeds:- Hot water works so maybe a  large Fresnel magnifying glass? :-)   Salt water from redundant battery project?   

Friendly jokes aside, my wind turbine project is on the back burner because of the stacks of solar power to burn from latest purchases of 250W panels at AUD $60 each. =  Power during clouds and some rain. Getting 10KW air/con soon. Uses about 2.3kw power. Will run during good sun when panels are producing 9kw.  Also contemplating induction heating stove top cooking, Again probably sunny times but the way the battery picks up after 2 hours of sune next day, whwo knows when we will cook on the battery.

But when that project is finalised, I'll return to HAWT with a tilt up head for protection. Not sideways.    It is far easier than one thinks and with the strength of steel in mind and reasonable design it wont be a too  worrying weight up top.

Like you, I've thought about VAWT,  and not just about the inefficiencies but the larger and more fragile rotating assembly up top started to daunt those ideas. 

Conversely;- glad to hear you have lost 20kg Naam and from what one reads, it takes determination NOT to find it again. :-)      Sincerely;-  good on ya mate.

I bought small Chinese strip lights that were supposed to be 6W but were more like 2W. Then when the truthful ones came, they sure needed heat sinks. GREAT for Georges practical projects for  remote.  Also very happy with the roll of LED strip lights. Not too fiddly to cut to lengths and get access to the top side for the 12V wiring.

Recently  I bought some 19W    four foot LED "flouro" type tubes. Brilliant! But some were closer  to warm white when they stated a certain colour but the frequency gave it away. Never mind;- great for home. Simply exchange into the flouro batten.

 

 

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Guys--- BEWARE of some Chinese lithium 18650 batteries. Especially the yellow "Ultrafire" brand.

Apart from claiming to be 9800mAh and are probably way less capacity than the best that are actually around 2000mAh.

They are prone to catching on fire according to those who have been caught. Good brand name eh. 

I also bought one of those 5 cells holder/charger like your picture above George and planned to happily use some yellow Ultrafires but don't know what to do now.     Maybe throw them at the noisy 5am crows. :-)

Twenty cells cost about $21.    "If it sounds too good to be true, it probably is"    and it was.     :-(

 

 

 

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I am currently testing this very very bright AC/DC lamp with build in powerbank. Measured the voltage at the led when its burning. No stepup used ???? So its between 3-4.2 volt. Turns on in case of electric fall out. With overcharge and discharge protection. 

I myself charge only DC. 

 

Electronics inside seems to be of descent quality when you connect this lamp to a standard AC fitting.

 

Amazing price of 70.000 Indonesian Rupiahs (about 5.60 USD), 3000 mAh (2x li-ion).

 

The idea: charge it and bring it everywhere you want and hang it up anywhere you want without cable (after charging) :) 

 

Handy for villages without electric or offgrid living

 

Jingjoe, you are right. Be careful what you buy ref li-ion 18650 batteries. 

 

lamp.JPG

Edited by George Harmony
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I have looked at the vanadium battery a few times and always come to the same conclusion. It is too big and too expensive for me. There is an interesting innovation for lead acid batteries which reduces sulphation and increases cycle life allegedly. It is a simple matter of adding a few carbon nano tubes to the plates http://www.thebatteryshow.com/resources/news/2016/09/05/lead-acid-batteries-achieve-4x-longer-cycle-life-using-single-wall-carbon-nanotubes/ 

Good to see you happy with your new power source Joe. If you are thinking of using this to charge batteries then it's as well to bear in mind that you will have 4.5 hours per day of direct sunlight on the panels. If this is used for battery charging and running your aircon you may need more panels. It depends on your air con power and battery size.

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On 21/11/2016 at 0:44 PM, George Harmony said:

What do you think of this??

http://galaprojects.com/super-battery/

 

 

I'm never going to be convinced that any DIY battery can out do a commercial unit on a cost or performance basis. Particularly one where you have to load an "offer" in order to access the instructions. I don't own any Apple devices anyway so no way to take up the "offers".

 

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On 10/12/2016 at 4:37 PM, KonaRain said:

Wow, thanks..
Re: Solar Panels, hard to beat $1 per watt..
Aloha, Boys..

The 250W panels I bought second hand 8 months old were about $61 each. And they will be getting cheaper, and even the 310 W  panels too.

Bought another 24 x 250W panels recently and will install 18 of them, the max. the second identical Midnite controller will handle.

This will make 9kw.  Even with the existing 18 panels the aircon can run all day and the batts are still fully charged by sundown.   22kwh per day with the aircon running is typical collection at present.  

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On 11/12/2016 at 9:30 AM, Crossy said:

 

I'm never going to be convinced that any DIY battery can out do a commercial unit on a cost or performance basis. Particularly one where you have to load an "offer" in order to access the instructions. I don't own any Apple devices anyway so no way to take up the "offers".

 

Thanks Crossy for the URL.  I didn't want to download but accepted your word of scepticism.     

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  • 4 weeks later...
The 250W panels I bought second hand 8 months old were about $61 each. And they will be getting cheaper, and even the 310 W  panels too.
Bought another 24 x 250W panels recently and will install 18 of them, the max. the second identical Midnite controller will handle.
This will make 9kw.  Even with the existing 18 panels the aircon can run all day and the batts are still fully charged by sundown.   22kwh per day with the aircon running is typical collection at present.  

Do you expect to get full voltage from used panels?
Aloha!
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Good to see you again Konarain

Solar panels deteriorate with time and exposure to sunlight. Providing there are no other faults then at 25 years old they will still give something like 80% of their original rated output. Joes panels are eight months old so if they are in good condition the output will be as close to new as you could wish for. I think the deterioration is linear so at eight months old the panels will be 2.1% down and with an MPPT controller that is unnoticeable. It's worth mentioning that solar panel companies specify the output rating of their panels at 25 deg. C. As the temperature rises due to the ambient temperature, the sun's radiation and self heating when working, the output will drop. I can't remember what the figures are but this drop can be as high as 25% when loaded in full sunlight at 40 deg. ambient. A good way to keep them cool could be to arrange cold water to flow over them. recovery of the water would yield a supply of warm water.

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  • 4 weeks later...

Where are you George? How are the experiments going?

The air-con here has been a blessing with the recent heat waves in Oz.

You might remember I wondered about the panel angles where you are right on the equator?

Been learning much since my  current belief and experience is;

have them almost flat and have a few more panels if you can,

Reason being to aim for maximum power on minimum days with clouds/rain.

With cloud cover, the radiation direction is straight down from the clouds above.

I happen to have one group of 3 panels at about 23 degrees and the other 5 groups at 5 degrees North  and the groups are individually wired and switched  to my switchboard (This was a topic once).  The 23 degree group puts out marginally more than any other group on a sunny day           but the reverse is true  on cloudy days.  

Since you will surely have hot days that are cloudy, if you have a spray system to cool your roof (and this has been a topic too) try cooling the panels too and notice a considerable increase  in solar power.         I noticed more power and it didn't use much power to pump it,   and the water wasn't lost (except some evaporation) but I have so much panel power over my needs its not worth the effort but just passing this on to this forum. 

 

 

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Hi Jingjoe. That's a very interesting observation re. cloud and solar panel angle. Did you make any power measurements? 

The sprayed water idea is a good one to keep the panels working at maximum efficiency. If you can collect the water after it's done it's cooling job, you've also got a supply of warm water.

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On 02/02/2017 at 0:32 PM, Muhendis said:

Hi Jingjoe. That's a very interesting observation re. cloud and solar panel angle. Did you make any power measurements? 

The sprayed water idea is a good one to keep the panels working at maximum efficiency. If you can collect the water after it's done it's cooling job, you've also got a supply of warm water.

Hi M.   Good to hear from  you.      Seems we are alone?      I must email George.     Nice bloke.   

I cant remember the differences in power between the two different inclinations  on that cloudy day but can do so again.

BUT;-   We are in extreme heatwave conditions now and very little cloud or rain predicted soon. :sad:

 

I could easily get figures for hot versus sprayed panels.  Must be careful not to thermally shock them and possibly crack glass.    One VERY fascinating phenomenon was "magnification" one day for about 5 minutes.   You might know but I didn't.

Had it explained later that; when a certain size round cloud intervenes  between sun and panels,  the cloud perimeter acts like a magnifying lens  and accounted for a considerable increase in power while the cloud passed.     I firstly  noticed the increase in panel voltage and got a bit worried about the limits of the MPPT tracker controller.

Just lucky to have been watching at the time and suppose I could patiently wait again but it is documented somewhere on-line.

 

Re warm water, it could well be very hot water depending on roof and panel areas.  This could be good for any newbies watching this but my solar hot water is still conveniently great,  I have an 1800 W  element in the tank now for emergency from a generator, or from surplus P.V. via the inverter,  and there's another 18 panels (4500 W) going up soon for cloudy days.    and a $60 Chinese instant LPG gas shower heater when its zero outside and a week of clouds. 

 

 

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On 10/01/2017 at 8:38 AM, KonaRain said:


Do you expect to get full voltage from used panels?
Aloha!

Hi Kona sorry I just noticed your post.   As far as I can measure yes I am getting full specs.,   and because the Jinko brand are well regarded i believe they will serve well into the future too.      Because of the absolute overkill of panels to my needs it wont matter if there is a decline and M has given a good reply as usual.  

Aloha to you too.   :smile:

P.S. the only reason they were removed from the original installation was the roof needed changing so the solar guy had to remove  them first and talked them into replacing with 310 W panels and they were able to get the government grants so to do.      So--- Win win for me too.  

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On 02/02/2017 at 0:32 PM, Muhendis said:

Hi Jingjoe. That's a very interesting observation re. cloud and solar panel angle. Did you make any power measurements? 

The sprayed water idea is a good one to keep the panels working at maximum efficiency. If you can collect the water after it's done it's cooling job, you've also got a supply of warm water.

Just for you M    :-)      I bought a 15 metre lawn spray flat hose with squillions of pin holes and laid it along the full length of 5 of the 6 groups of panels.  The voltage of the whole group was 79 before turning on the water and went to 91.5V after 10 minutes.  Outside temp today is only 33 and when strapping the end of the spray hose to the end panel, the panel was too hot to touch. 

Other than a minimal house load toady I'm running an 1100 W water pump transferring thousands of litres to my neighbour and even with that load there's heaps too much  power coming in so may turn off the water spray.

House supply water is pumped up to the 1300 Litre header tank by a beautiful little solar powered Tops Flo pump. I've mentioned this ages ago.   Brush-less, P.V. friendly,   magnetically coupled and 9 Metre head possibility.

 

 

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1 hour ago, KonaRain said:

Great, I'm gonma get a propane water heater, cause I live in da clouds..
 

RSQ-B6Y  MountainNet 6L is the brand I got and VERY pleased. Couldn't find the purchase  web site sorry. . Runs from very little water head pressure and starts making hot water in 8 seconds.    Needs 2 x D size cells for automatic spark ignition.  I got a manual change over diversion tap/valve so the water that normally gets fed to the shower head can go to the gas heater or the original shower head. It comes with its own suitable plastic shower rose.   Operate the pull-out diversion tap, turn battery switch on,  turn on the cold water fully, it ignites and after some practice of adjusting gas burners etc  its a simple routine.  Great.  Has two burners and one can be shut off.  No digital temp display but that's ok.

Don't reckon it uses much gas for a 3 minute shower. Could be carbon monoxide in a small enclosed room. Not mine.

Oloha

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7 hours ago, Arjen said:

About cooling the PV modules, I record the performance from my solarsystem with a PLC.

I record every 10 seconds thinks like temperature, voltage, amperage, battery voltage, supply from my own inverter, and supply from the grid.

 

My PV modules are facing perfect south, I can see cearly that in the morning (cold panels) the perform much better then in the afternoon.

 

Arjen.

Hi Arjen.   how cold is it in the mornings?  If you are connected to the grid then do you feed back to the grid and get paid per kwh?   here in Australia many people still get about 50c per kwh but many are down to 7cents now. Where are you? 

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On 08/02/2017 at 8:19 PM, Arjen said:

Thailand forum, so I am in Thailand.

I am connected to the grid, but store my electricity in batteries in case from a black-out (happens often) When batteries are full I also use my own electricity, and disconnect from the grid. 

 

Now it is cold. In the morning PV modules are arund 20 degrees. In the afternoon around 60.

 

My system is designed as a whole house UPS. And when batteries are full charged I use this electricity also.

 

Arjen.

 

 

Hi Arjen. Thought for a minute you might be way up north of equator with "panels facing due south".  Many  contributing this forum like me are not in Thailand but have or did have Thai connections.    Do you not just have black-outs but brown-outs as well when grid voltage goes down from 240 to say 180V.     Another forum some time ago had lots to say about this and the danger to refrigeration/aircon  compressors.  What kind  and size batteries  do you have?   Do you have a MPPT solar controller?   A friend wants to buy a Chinese inverter. What size and brand  inverter are you happy with?       P.S. I smiled when you said it is cold at 20 degrees.     Just like my Thai relatives would say.   :-)   Some places in Oz will have 40+ any day now and sometimes we have zero at home here. Cant wait to see how my new aircon will warm the house then.   :-)

Cheers from Jing Joe.

   

Edited by Jing Joe
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4 hours ago, Arjen said:

Hi Jing Joe

 

We also often have brown-outs. I have a phase protector, what gives in case from black- and brown-out a signal to the PLC, and then we change over to my own supply. Works good for now. In the worst case I can supply my own electricity for about 48 hours, but in that case I must be carefull with our consumption. Usual I run for 8 hours daily on my own supply. In case from black/brwon out I run my own supply till inverter stops running because of under voltage from batteries. In case from normal running I go back to the grid when batterie voltage is below 24.5V, so I have capacity left for a black/brown out to cover. It takes maximum 20 seconds to switch from grid to my own supply. In case from a black-out, we are for maximum 20 seconds in the dark. In case from a brown-out or a normal change you hardly notice the switching between grid and my own supply, although you can here it usual when motors are running because phase difference.

 

On attached spreadsheet from 08-02-2017 you can see at 09:06:06 a black-out happening what lasted till 15:42:15

 

I use now Leonics charger and inverter. The durability is acceptable (some problems, all solved under warrantly), but the service from Leonics (considering it is a Thai company) is very good.

Charger is not MPPT, when I installed my PV modules (15 years back) I think they where not available. I wanted to change to a MPPT charger, but that included rewiring the panels. So not....

 

I have 20  piece 12V 100Ah deep cycle batteries from Nubos. Connected in 24V. I am not so happy with these.

 

Arjen.

08 tv.xlsx

Great info thanks. Read it twice and lots to glean from it.  Just a quickie for now>> Didn't know Leonice brand but had a good search and WOW is this some inverter-    www.leonics.com/product/renewable/inverter/inverter_apollo_s-210_en.php

What model is yours?   I couldn't find the attachment you spoke of but will look harder.

I've passed it on to the mate who is looking for an inverter. 

 

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1 hour ago, Arjen said:

And I am sure a lot of people who know all better then me will say I am crazy to spend this amount of money.

four years ago i bought two cars. for one i paid 7.6 million, for the other one 4.5 million. the "cheap" one i used once a week on a sunday morning for a couple of hours to drive around with my dogs. and never in my whole life i cared a flying fart what people say. but then... to each his own :saai:

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On 10/02/2017 at 2:59 PM, Arjen said:

Hi Jing Joe

 

We also often have brown-outs. I have a phase protector, what gives in case from black- and brown-out a signal to the PLC, and then we change over to my own supply. Works good for now. In the worst case I can supply my own electricity for about 48 hours, but in that case I must be carefull with our consumption. Usual I run for 8 hours daily on my own supply. In case from black/brwon out I run my own supply till inverter stops running because of under voltage from batteries. In case from normal running I go back to the grid when batterie voltage is below 24.5V, so I have capacity left for a black/brown out to cover. It takes maximum 20 seconds to switch from grid to my own supply. In case from a black-out, we are for maximum 20 seconds in the dark. In case from a brown-out or a normal change you hardly notice the switching between grid and my own supply, although you can here it usual when motors are running because phase difference.

 

On attached spreadsheet from 08-02-2017 you can see at 09:06:06 a black-out happening what lasted till 15:42:15

 

I use now Leonics charger and inverter. The durability is acceptable (some problems, all solved under warrantly), but the service from Leonics (considering it is a Thai company) is very good.

Charger is not MPPT, when I installed my PV modules (15 years back) I think they where not available. I wanted to change to a MPPT charger, but that included rewiring the panels. So not....

 

I have 20  piece 12V 100Ah deep cycle batteries from Nubos. Connected in 24V. I am not so happy with these.

 

Arjen.

08 tv.xlsx

Great info thanks. Read it twice and lots to glean from it.  Just a quickie for now>> Didn't know Leonice brand but had a good search and WOW is this some inverter-    www.leonics.com/product/renewable/inverter/inverter_apollo_s-210_en.php

What model is yours?   I couldn't find the attachment you spoke of but will look harder.

I've passed it on to the mate who is looking for an inverter. 

 

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(I've not been following this thread, so my apologies if this product has been discussed.  The size of the thread is too intimidating to try to go back and read it from the beginning.)

 

This showed up in my Facebook feed today:  SmartFlower.  It looks intriguing, but the big question I have is how much it might cost.  I could imagine a high-rise office or condo rooftop with a "garden" of SmartFlowers tracking the sun.  They also have a FAQ with more information.

 

The Austrian company seems to have geared its info toward the Euro market, addressing such things as sub-zero temps, frost and snow.  Would it be any less appropriate/effective in Thailand's tropical climate?

 

Is this a realistic product, or just a gimmicky "feel good, look nice" product?

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