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MasterCATZ Regular Member Joined: 25/03/2011 Location: AustraliaPosts: 52
Posted: 07:34pm 07 May 2019
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well I am about to build another set for an 15kw 3 phase offgrid solar system for running my cold-room and aquariums after reading this https://phys.org/news/2018-01-inexpensive-stablethe-salt-battery.html
I am wanting to give naFSI (precise name: sodium bis(fluorosulfonyl)imide) a go but I can only find it @ $70 per gram ... if anyone knows where I might be able to find it at a reasonable price in kg form I am all ears
next issue is working out where to hide/ burry these cells the only room I have left is along the fence-line , I am wondering if it might be able to directly charge these cells from the solar panels ( 270watt panels ) then have the solar inverters run directly from them ( but then again I shot my self in the foot doing 500v DC input 3x PIP-5048MG 120-430V maybe I should have done 3x PIP-5048MS 60-115v ) and then the inverters can charge up the 48-66v 18650 powerwall ( still deciding if I should make my own banks or just get some salvaged tesla batteries ) but I wanted the higher PV voltage to cut down the wire costs running back to the house
the solar panels and saltwater cells would be in parallel and yes the saltwater cells will have diodes on them .. so the inverter would be pulling most of the energy from the solar panels anyhow as the saltwater cells have a low current rating and I would need 10x as many to actually be able to use them 100% , and this is the main downfall of the cells
reason for this is I do not have to worry about the charge state of the saltwater cells they can be overcharged and discharged with out any issues and as their is no room for me to have saltwater cells anywhere near a charger under the house , but having 48-60 solar panels ( still deciding if I will go portrait mode which will be 8 panels per 8m frame @ 4320 watts per inverter or landscape mode 10x panels per frame 5400watts per inverter ) this would mean I need to make nearly 1000 salt water cells to get the required voltage , eek , but I should be able to slowly expand this over time in 40V batches ( 1 batch per solar panel )
such a shame Aquion Energy went bankrupt
but technically I am now retired so , I have all the time I need to tinker now just need to buy one of those head mounted camera's so I can start up a youtube project page :P
how ever I have also discovered Sodium can apparently be used as the anode its self and the use of Na metal as anode instead of hard carbon can apparently massively increase the energy output by about 30% due to the higher capacity and lower potential ( still trying to find its potential value)
so I am still trying to work out how this can work with saltwater as an electrolyte someone was saying ionic liquid? as the breakdown voltage is much higher. To achieve an ionic liquid you combine some alcohol like methanol or ethanol, with a salt for ion mobility. I would still use manganese as cathode I do not know of anything better
https://structx.com/Material_Properties_001.html
Magnesium and Graphite would be best matches , graphite being cheap to make DIY also
wow it is only 2 years later and Magnesium now 10x the price I paid last time I was wanting to buy it as an foam/felt anode to cut down on labour trying to make it with powder but I guess I still can not cheat as I can only get it as rods / sheet / wire / ribbon and powder forms
powder form is cheapest but sheet form expensive !! it really is a pain rolling these up in powder form especially when you want to get it inside a 90mm 3m long pipe by your self..
Graphite felt 1.2mm thick $1 /m2 or $15 per kg PP /PE film battery separator $2 /m2 or $5 m/2 with glass matting
instead of using cotton/fibreglass matting this time but I still need to think of a way to stop the powder falling through the bottom when rolled up and sitting upright ideally I need a large sheet of film I can fold in half , issue is it eventually unravels a bit once I get it in the pipe and I have nothing helping stop the powder fall , I think this is why they manufacture the cells laying horizontal and not vertically , of cause I am trying to do this on the cheap as well the last set cost me $2500 for the 20kwh storage and its performance does seem to be falling now , the only other thing would be just use manganese wire
Edited by MasterCATZ 2019-05-09
Warpspeed Guru Joined: 09/08/2007 Location: AustraliaPosts: 4406
Posted: 01:20am 08 May 2019
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You will need to phone around the chemical supply companies.
Most things are available in several different grades. Medical/reagent grade will be the purest and by far most expensive. Then there is commercial/industrial/bulk grade that will come in huge drums or sacks and be vastly cheaper.
Find out the common uses of that chemical. It may be used by the truck load in agriculture or some common industrial process, and obtaining it in bulk at reasonable cost no problem at all.
Its probably a case of doing some research and getting onto the right sales person at the right company. Find out what its used for and say you want to use it for that purpose. If they think you are "not in the trade" they will probably try to rip you off.Cheers, Tony.
MasterCATZ Regular Member Joined: 25/03/2011 Location: AustraliaPosts: 52
Posted: 12:18pm 08 May 2019
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as someone asked what my cells capacity was
the old bank stored 15w per L and could charge / discharge @ 4w per L
the cells were 3m long 90mm PVC downpipe and held 20L ( originally they ea held 500wh but now only 300wh) and they were impossible to get back out of the ground for maintenance the ones I did try I broke as the tops were brittle I believe my manganese powder fell to the bottom
this time around I will only do 1.5m ~10L or maybe only 1m ~6L but should only need to go ~50cm long to hold 1 days worth of power produced from 270w solar panel
my 270w panels are 38.3 Voc 9.2A Isc @ 1.25v I would need at least 30 cells per solar panel and 70L worth of volume to handle charge and 90L to store that days energy I had also found efficiency was around 80% if you were doing upper limits so if I double the capacity it should be all good
this essentially means I need a 1m x 30 cm wide trench under each of my ground mounted solar panels tho my auger is 300mm so hopefully I can get away with doing just a few holes
BenandAmber Guru Joined: 16/02/2019 Location: United StatesPosts: 961
Posted: 01:36am 09 May 2019
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So far from everything I've read and everything I've Been Told
If you can get a cheap forklift battery and able to move it into place that's the way to go
I am very interested just like all the rest of you guys on any good cheap battery solution
Now if you're really really lucky And can find a piece of property that has a stream that runs year-round
with enough water flow that's better than all the other options if you ask mebe warned i am good parrot but Dumber than a box of rocks
Boppa Guru Joined: 08/11/2016 Location: AustraliaPosts: 814
Posted: 02:10am 09 May 2019
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I set up several microhydro setups back when I was doing solar offgrid installs (the Rainbow Power ones, they were literally down the road from me back then) which were basically a modified car alternator (they made a pelton wheel drive for car alternators) that required very little head on a small stream- one I put in had a stream you could literally jump over, but it ran all year, a small dam about two foot high in a small gully was a piece of cake to build (we put in a fairly large pvc pipe that diverted the flow while we built the dam wall above it, it had a offset outlet that went to the pelton wheel, but flow to it and to let straight through was done simply by unscrewing the pvc 'cap' off
We made a neat 'self cleaning' screen to the pelton wheel with a pvc t piece that had a second pipe straight through the dam wall a bit higher than the outlet the screen was on the bottom of the tee that went to the wheel outlet- the advantage was that if your screen got blocked with leaves or whatever, by opening that top outlet, the water flowing through that pipe would 'suck' all the debris off the top of the screen and out through that pipe
MasterCATZ Regular Member Joined: 25/03/2011 Location: AustraliaPosts: 52
Posted: 03:07am 09 May 2019
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actually I think one of the good ones is having a steep hill and pumping water to top or lifting something heavy that can be released for power later on
which is actually my next goal we have 10m drop and I have 500W-Micro Hydro Turbine Generator's that works with 6m head, excess power will be used to pump water up into 3x 30kl tanks top of hill from the gully or bore ( unfortunately we don't have flowing water here ) then reclaim the power when needed
anyone know of a good head cam ? I wear glasses so can not really use the spy glasses unless I go contacts , and do not want to wear a helmet / bulky gopro .. just a small camera that can hook on head somehow or clips onto glass's
Edited by MasterCATZ 2019-05-10
Boppa Guru Joined: 08/11/2016 Location: AustraliaPosts: 814
Posted: 03:21am 09 May 2019
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I bought one thats in a cap LOL (I used to wear it into work...isn't it grand having a boss who lies constantly...)
Same as these
MasterCATZ Regular Member Joined: 25/03/2011 Location: AustraliaPosts: 52
Posted: 03:28am 09 May 2019
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ok new google baseball cap camera thanks it will be a start at least been 20 yrs since I last wore one :P
Notice. New forum software under development. It's going to miss a few functions and look a bit ugly for a while, but I'm working on it full time now as the old forum was too unstable. Couple days, all good. If you notice any issues, please contact me.
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