Well, the way I look at it the battery/solar-combination can only be justified in an off-grid situation. As long as you’re grid-connected you can’t compete money/work-wise.
Different story if you do what I just did - go big on the solar, sell surplus to the grid and scrap the batteries. Powerouts will have to be dealt with separately.
Edit: But as always…If you already have the batteries…a couple of panels won’t add too much to the cost. My point is problem is batteries, not solar.
Jan I agree with you, hopefully Billy’s power service will actually buy back produced energy. Some companies it’s a wash even if you’re making more than consuming. They just say “thanks for the electricity, sucker!”
If I had a 100% contractual guarantee from my provider to buy overproduction I would do grid tie, and battery backup powered by a DC generator. Like hedging my bets basically.
Before I installed the solar I reserched the battery option some. A brand new set of batteries costs about $1,000 per kWh storage capacity (plug and play). Let’s say you settle for 5 kWh - that’s $5,000 and it will pretty much cover running fridge and freezers over night and that’s it.
Different story of course if a used EV battery happens to fall into your lap. 5-10 times more storage capacity if it’s a modern battery, but it would require a rather pricy inverter to get a smooth AC-voltage with enough amps to be useful.
Cody, that’s true over here as well, only we can choose which power service we like to do business with. I will be producing maybe 3 times my consumption and I’m on the lookout for which one will pay the most for the electricity I make, even if the the smaller part I’m buying is a bit more expensive.
I think one way to have both grid tie and battery backup is to have AC to DC battery chargers to keep the battery at a ready voltage. Then if the bank gets low you could charge them with a generator or maybe have a portion of panels set aside to charge.
If you’re overproducing then you’re tending the batteries for free. You can charge them with a woodgas driven genset for an extended outage.
I am no expert but I would look for
Monochrystal, they do better over time. Cost for good brands are around 0,80 €/Wp for complete systems. Only panels go for 0,40 €/Wp. Second hand less then half. So Tom has a good deal but not special.
Batteries where €120/kWh if you buy LifePo4 with Daly BMS from Alie. 10 times cheaper JO, if you DIY. My friend is on his way to Poland to get a batt from a wrecked Nissan Leaf 65 kWh and sells his old one for €3000 with 24 kWh usable power. Good deal!
So, it depends what your needs are, but PV I can recommend if you use electricity. No matter on or off grid. After a few years you get free energy. For me a no brainer unless you are in a deep dark valley. Off grid you need batteries of course. Lead acid is fossile, not for today. Lots of batt packs coming available now. Battery Hookup is solid, we ordered some there. Now and then they sell nice packs.
If you can build a reliable gasifier, solar and batt is peanuts.
So, @BillyAlabama it looks like it depends who you ask 
I tend to factor in what I can fix. If I run out of wood I can fix it. If I end up with a dead LifePo4 I’m lost
Not really. Woodgasgenerator fits in. If you somehow mess up your battery, you are not lost. But woodgas is not free, you have to pay a price. Not in money but in effort.
We have a solar system. 7kw. Pseudo grid tied.
Meaning that I can switch all or selective parts of our compound over to grid if I need to. We do not feed back into the grid.
The problem as many have noted is storage. Batteries.
I spent a few years mucking around with that topic … for us in the equatorial tropics … the only battery chemistry robust enough to make sense was nickel based. NiFe or NiCd.
Every other battery technology is absolutely killed by heat. And work around strategies such as cooling the battery space eventually worked out to be a “Red Queen dilemma”. Producing just enough power to cool the space so you could … produce power.
Nickel cells are EXPENSIVE. But they are very robust, and by in large serviceable. You can take them apart and work on them.
We first purchased old cells and rebuilt them. Then later purchased new cells. I have cells that are 40+ years old in production behind me as I type.
Should you end up in the circumstance of having Nickel cells, I have a manual that I developed from that time shows how to maintain, overhaul, and rebuild cells. Ask and I’ll send it to you.
What I tell most folks in my bario, is to have a small solar setup. A few panels, basic charge controller, inverter. Just for emergencies like charging cell phones or running medical equipment. Use the worst batteries you can scrounge. They are gonna die anyway.
Have a good generator setup that can run off of fuel you produce from local materials yourself. Have two generators or follow the military logistics rule of “three is two, two is one, and one is none”.
Investigate absorption refrigeration, (propane),. Those units are more reliable than compressor driven chillers. And from my thinking more economical than electrical powered in the long run.
And get acclimated to living without electricity.
Where you can find this stuff up in the “land of the big PX” I cannot help you with. But I can say that I am extremely impressed with the Jinko series panels. I have the 460 watt panels and they consistently produce in excess of their maximum rating.
Being on the equator and having them mounted on an active tracking base may be why, but they are sweet panels none the less. I believe that “Canadian Solar” is reselling or OEM’ing that line.
I have 2010 era Outback inverters, and I have nothing but good things to say about them. Keeping that in mind Outback was bought out by Alpha in 2011 and their product has gone to sh_t since.
Hope this helps.
Hi Billy, I bought 20 285w panels from; https://store.santansolar.com/product/sunpower-327w-e20/
Hi Billy since about 2015 i have not paid more than 20 odd $$ for solar panels , in fact the last load of panels i paid for cost me a slab of beer ( 10 for the price of $40 ), we get panels coming into the scrap yard these days brought in by installers doing upgrades or insurance work .
Facebook market place you see panels for free or a drink at least once a week over here in Australia .
Dave
Thanks to all. JO…The only reason I want a backup is to produce minimal power when the grid fails indefinatly, long term. Hardcore shtf stuff…without having to always fire a wood generator.
We also are stockpiling from our kiln dried, precut to WK-size, just-have-to-haul -it maple chunks. First wave goal is 200,000 lbs. Making good progress on that.
But woodgas power for every little electrical “need” is very tedious.
Yes, learning to live without power is the first and primary function/skill of grid down scenarios. We can do that, we have done that. But a little here and there makes all the difference.
I hate solar panels as a general rule. They are ugly, they are shiny, they fly away in the wind, .
We are in a co-op that mandates that they buy our power. But I am not very concerned with doing that. I like to have the grid for cheap on-demand power. Getting into a contractual arrangement with them gives more control of my life over to someone else. It doesn’t pay that well in my opinion.
I think I am more inclined to gather what I need for a backup system by getting batteries, controllers, etc. and then planning to charge primarily with woodgas if necessary. We’re also working on a pond at the moment…which will eventually produce a water wheel or turbine project…
I read a vote for NiFe or NiCd. batts. There was another suggestion to simply use whatever batteries could be scrounged.
Does anyone have more insight on the battery part? This is one area that I have definitely never learned enough.
It gets pretty hot here as well.
Anyone knowledgeable want to take a guess at this…
If one were to take a stack of lead acid car batteries and wire them up to an inverter and charge with a generator to run a well pump, couple of lights, maybe a small freezer…what kind of life span would they have?
Same question with deep cycle marine batts?
The only issue with car batteries is they don’t have the longevity. The cell plates are thin and perforated for high amp demand.
Golf cart batteries or gel batteries are the better to go for with Lead.
If I had the budget and space I would absolutely love NiFe. 100 year long potential service life when taken care of? Hot dog! Just top it off with water and it uses alkaline electrolyte, potassium hydroxide. There’s still Edison batteries kicking around in their wooden boxes that hold a semblance of a charge, the old Baker Electric cars used them. I’ve never had an NiFe battery in front of me, I looked them up when Mark mentioned them. Not sure where to go looking for them I’ve seen some steep prices.
Lead is all I know, and you can bring some back using an inverter welder. Tons of videos about that. Even a gel battery you can bring back if you take the vent caps out and top off with distilled water and zap it, damaged cell notwithstanding. Dad when he gave me his Club Car had 6 old totally dead 6v flooded cells and I’ve brought back two so far. Still need to do an amphours test.
I have the same power goals as you Billy. Establish my own grid to run essentials. If I had a better paying job I’d be closer to my personal goals for the property. Right now I’m curbing my expectations and having manual backup plans for things like the well. Gardening I already do by hand, the tiller on my Kubota can’t touch this clay.
I’d like to go as battery less as possible. For the well pump I’ve seen people use the direct DC voltage after a controller on a DC powered pump. They pump it to either an oversized pressure tank or to a holding tank/water tower and use gravity for their head pressure.
I’m sure there’s other things one can power directly/passively off a dedicated panel. For house cooling you could run a swamp cooler and a solar powered fan to blow the cooled air in ducts.
All of the Amish with solar pannels and wind generators around Indiana use old forklift batteries. The might not be best or cheapest, but there are a lot of families using them. They buy them refurbished from Ohio or Pennsylvania and have them shipped here
I have a bank of 4 hd 1000cca truck batteries, they were seven years old when I got them and weak. 5 years later they are still banked up and doing work, powers my carport and shed lights and occasional power tools. When I first lit my truck off they were powering my table saw to make chunks. Far from perfect but it’s what I have and it’s serving the purpose. Regular old lead batteries. Needs lots of recovery time during peak sun and bulk charge with a renogy 40 amp charge controller, 2 panels totalling 600+ watts. Entry level system that got my toes wet and saved a couple bucks. Batteries are what a solar system lives and dies by in my opinion, having storage to meet your needs and the solar to keep it topped up. I will eventually get my hands on some forklift batteries to upgrade with, just not the time or money for it at the moment
When I was at FOB Abu Ghraib, Iraq I was allowed to run the exact experiment you describe. I had new truck batteries, without the electrolyte poured in. I had a variety of generators. I had some 7000watt 240vac three phase inverters. I had an insulated and refrigerated container. I had no panels. I had limited fuel, but enough.
I loaded the batteries into the refrigerated container, added the electrolyte, wired them in series parallel. I ran the inverters at night. Charged the batteries all day while I worked.
The whole thing was unsustainable. The batteries died a brutal death. They had to be refrigerated, from April until November. During that time the night time temperature never dropped below 100F. I spared no amount of fuel, and even burned used motor oil an LDS465 multi-fuel engine for months to keep them charged. It didn’t matter, the heat and dust killed them, We never could enjoy a whole night’s tv, ac, and lights without the battery voltage dropping out.
The reason this failed. We could not keep the batteries below 80f long enough to get any longevity out of them. They also were shorting out because of the alkaline dust building up across the tops. We could not stop the dust. I eventually gave up on a pure battery system and moved to a hybrid system where we would charge the batteries as we used the inverter. Finally, switching over to Kubota powered generators.
I had some experimental solar panels that were useless too. Dust covered them so fast as to make them completely useless.
Conclusion? I would determine how long Li-ion tool batteries are lasting in your area. If they survive the heat, then start collecting them and buy a battery management system and start building banks. I am pleased with their performance here in the cold. I see the price for a 100ah LiFePO4 battery is only slightly more then a 100ah lead acid AGM battery.
Right now we are trialing all three, Li-ion, AGM, and LiFePO4.
You may not like panels, but you sure don’t have to listen to them.
This is a picture of Li-ion cells 18650 (18mmX65mm) I am salvaging.
I’m sure everybody here knows more about this stuff that I do Billy. Not many know as much about what’s coming and I can’t beat that horse any longer. My philosophy is always, Never be dependent on outside sources for things I need or desire in the event there are no outside sources. PV? great right now. Not so when the sun is blocked by trapped volcanic ejected matter for a long period of time. Not survivable when exposed to sulfur dioxide laden rain. Lead acid batteries are everywhere. You can rebuild them or strip them down to basic components and make your own. This way is not for people who believe we are just experiencing repairable glitches in the bright and shiny future.
I’m here on DOW because I threw big money and bigger time at solar.
All batteries … ALL … are chemical houses made from cards.
Average life span 3 or 4 years. Good life span 7 or 8. Lucky, (or expensive as hell), 10+.
So the real solution is to make what you need, from what is available in your yard.
my other idea is to go all the way in and work on MAKING my own batteries…devloping a semi-sustainable process for making batts.
Lots of vids on youtube showing what I’ve seen myself in developng countries…usually poorly ventilated mud huts with 10 year old boys smelting lead into plates and stacking them into recycled battery cases…
But who needs yet another process project…we’re in the middle of a gravel crusher at the moment…and 2 fish pond dams…and black diesel…and water wheel…need to build a new hay filter on the one truck…stockpiles of rice and beans…and ice pre season is here.
As long as you have the necessary tools and supplies then you have it beat whenever it comes up of the list.
