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LastOutlaw
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# Posted: 1 Jan 2019 02:12pm
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I am in the process of setting up my basic solar system and I am in the market for a 48V DC to 120/240V inverter charger for under $1000. I need to be able to run my water well (240v) in the event of loss of power. At first it will be a non grid tied system but eventually may want to grid tie as we build it up and add more batteries and panels. To start this system will use four 300 watt panels and eight 6volt batteries. I already have the panels, a Midnight Kidd charge controller and about 100 ft of AWG2 copper wire. From what I have gathered this system as it is will be operating at about half it's capability so we plan to add 8 more batteries and 4 more panels in the near future.
Can anyone recommend an inverter/charger for under $1000 ? Maybe something that will automatically switch to grid as needed down the road?
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ICC
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# Posted: 1 Jan 2019 03:55pm
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You didn't say how many watts output you'd need. The well pump may have a large start surge so that has to be determined and planned for with a larger enough capacity inverter. I don't know of any under $1000. I have used and like Schneider. .
Depending on long it needs to run the batteries may not have enough reserve. Lead-acid? 
Puzzled why you would start out off grid and then (maybe) get grid tied? Grid tie gets you into lots and lots of regulations and no way to get connected without a complete inspection checking for all the right little bits of hardware, especially if you also want to have batteries and have power when the grid goes down.
If the well pump is a big power user you might want to rethink the whole thing and change the pump for something like a Grundfoss SQFlex that does not have a power start surge and can even run direct off panels.
And use lithium batteries.
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LastOutlaw
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# Posted: 1 Jan 2019 05:01pm
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Yeah... you are pushing my system up a few more thousand dollars that I do not have. While I like Lith Ion I can not just run out and drop a couple thou on them. I certainly can't juts yank up my $500 well pump and drop in a $2200 Grundfoss SQFlex on top of the lith ion batteries. ICC where are you located? Where I am I doubt that anyone will want to come inspect anything. They don't even have building codes here. I'm looking to get something working to run my well in the event of a grid down emergency.I will not run this on my well full time. If I can get my system up and running off grid then I will be happy. I will then expand into more panels and more batteries after that.
I have tried to find electrical specs on my well pump to no avail.
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LastOutlaw
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# Posted: 1 Jan 2019 05:02pm - Edited by: LastOutlaw
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It is a 3/4 hp 3200 series 8gpm franklin electric deep well submersible 3 wire pump
BTW, i do have a 22kw backup generator as well.
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ICC
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# Posted: 1 Jan 2019 05:59pm
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Quoting: LastOutlaw ICC where are you located? Where I am I doubt that anyone will want to come inspect anything.
Northern NM where I'm watching the snow pile up to almost 2 feet new in the past 24 hours.  Pretty much as much as we had all last winter.
IF you are hooked into the grid and want to add solar into that mix you will be inspected. Guaranteed. If the grid can get to you so will their inspectors. The BIG thing they are, rightly, concerned about is to be 100% certain that if the grid goes down your system automatically separates from the grid. They do not want any chance whatsoever that your power could back feed into the grid and electrocute a lineman who is working on a dead grid.
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LastOutlaw
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# Posted: 1 Jan 2019 07:37pm
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ok, I could see the reasoning behind that. I will say though that my generator is hooked to my system via a grid/ generator switch and no one has ever come to inspect it. Now I don't know if that is the same thing or not. I do know that my generator does not feed into the grid.
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Atlincabin
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# Posted: 2 Jan 2019 09:16am
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I also don't see any way you can hook into the grid without an inspection, unless it is surreptitiously. In that case, you don't get any credit for adding power to the grid, and it would be dangerous as already noted.
I suggest just going grid-tied to begin with, and spend the battery money on panels and a larger inverter.
As far as inverters, have a look at the stuff they have at Wholesale Solar. I'm not shilling for them, but am a satisfied customer, having purchased a couple of systems (one off-grid, the other grid-tied) over the past few years. At the very least, it would give you an idea of what's out there and prices. I just installed 4 kW with an oversized inverter (future addition of panels) for $7k, which includes all the other bits and pieces needed. After the tax breaks (in the US anyway) that ends up less than $5k.
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LastOutlaw
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# Posted: 2 Jan 2019 09:43am
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I'm not trying to avoid an inspection. I don't care if they inspect or not. I'm trying to set a few things up here for the event of a grid down situation so I can still get water for my family and livestock, gardens etc without having to use a well bucket https://www.lehmans.com/product/lehmans-own-galvanized-well-bucket/
or spend $1100 for a deep well hand pump plus all the extra items needed to make it operable. Because I already have four 300 watt panels and a midnight Kidd controller I thought I would just put together that system with expansions added in later if needed to make it do the job. If I can get a fridge or freezer into that system as well I would be ecstatic. Now here is a catch about grid tied that I don't like. The local electric co-op will not cut you a check if you produce more electricity than you need. They only will give you a credit towards more electricity of theirs in a grid tied situation. I question the legality of this but that is a whole other battle. Besides it will be a loooong time before we ever reach that stage.
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ICC
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# Posted: 2 Jan 2019 09:46am
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Re the US alternative energy credit; to get the full 30% credit on solar the equipment must be bought and placed in service before the end of 2019. After that I think the credit is reduced. I forget by how much.
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Atlincabin
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# Posted: 2 Jan 2019 09:58am - Edited by: Atlincabin
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Credit decreases by a few percent each year after this year. 26% in 2020, 22% in 2021, then "permanent" 10% thereafter.
LastOutlaw, that is typical of most electric providers. I put in a system in our former home in NV (2012) when the state and power company were really pushing it, including a cash rebate for excess power. Long story short, the power company bought the PUC (Public Utilities Commission, a political body) and got them to allow the company to quit giving ANY credit or refund to anyone who produced excess power. Basically totally killed the solar industry in NV and screwed anyone like us who has put in solar. That finally got adjudicated and those who put in solar before the "buyout" were grandfathered in to at least get our electricity back, but has still hampered any real solar development in one of the best places on the continent for producing power. That made me hesitant to put in solar in our new place in CO but we did it anyway.
ok, rant over.
Best thing to do is try to size your system to fit about 95% of your needs. Alternatively, oversize a bit to allow for future growth and you can always use any excess running a heater or something at the end of the year. And remember that the panels will degrade a slight bit each year, so oversizing slightly is not a bad idea anyway.
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LastOutlaw
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# Posted: 2 Jan 2019 10:47am - Edited by: LastOutlaw
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Thanks @Atlincabin. I have something put together for me by MtnDon a few years back when I was considering using my panels on my off-
grid cabin. I ended up not adding panels there and using a battery bank i made out of trolling motor 12 volt batteries that I got a deal on at a car dealership I worked at and simply recharging with an EU2000 when I was there occasionally.
At this point I want to use the panels here on the homestead in the same configuration using the Midnight Kidd that I bought and the four 300 watt panels all still new in the box. Because we are on limited funds I am price shopping for 6 volt golf cart batteries available in my area. (within a 2 hour drive).
Now the original system was designed with the 12 volt batteries in mind and it worked out that using a 48 volt system put the MinKidd operating at half it's capability. Now because I'm looking at 8 six volt batteries rather than the eight 12 volt batteries I believe that I am better off to go to a 24 volt system.
Here is the system originally planned for the 12 volt batteries:
----------------------------------------
Here's a thought that works with 1 Kid charge controller
4 of the 300 watt panels; 2 series strings of 2 panels each and those series strings connected in parallel
48 volt battery bank
buy 2 more of those batteries; 2 series strings of 4 each, connected in parallel
Then when those batteries die buy some real RE batteries (like L-16's) or at least golf cart batteries
MtnDon
Member # Posted: 15 Sep 2014 18:22 - Edited by: MtnDon
Reply Quote
That has the Kid working at half capacity (amps) more or less. Better than working close to the maximum, as far as theory goes. It also cuts the parallel batteries down to only 2 deep; much better than as is now.
If those batteries are about 115 amp hours each then you would have 115 x 2 = 230 AH @ 48 volts = 11040 watt hours. At 50% max discharge = about 5 Kw usable power.
230 AH would be served well with a 20-25 amp charge input. The 4 panels on the Kid would supply 21 amps at 57.6 volts (equiv to 14.4 on a 12 volt battery). Just about ideal for charging.
Now find a 48 VDC inverter.
MtnDon
Member # Posted: 15 Sep 2014 18:28 - Edited by: MtnDon
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Quoting: MtnDon
Then when those batteries die buy some real RE batteries (like L-16's) or at least golf cart batteries
---------------------------------
The consensus was that splitting up the bank into two series strings was better than one long string of 8 batteries in parallel for the 12 volt batteries.
Now because I'm looking at eight 6 volt batteries it is probably better to do the same thing with them and set up two strings of 4 batteries wired in series and connected in parallel in order to keep the strings short ( which would work out to a 24 volt system) rather than one long string of eight batteries in parallel. (which would create a 48 volt system.)
Am I right in this line of thinking?
My run from panels to batteries and charge controller will be pretty short ( around 15 to 20 ft) and I have about 200 feet of 2AWG copper wire that I bought off a contractor a number of years ago that I have been sitting on.
'm thinking I need to buy a 24 volt 4000 to 6000 watt inverter/charger to use on this system and that should be enough to start up the well and maybe awhile later double the panels and batteries.
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creeky
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# Posted: 2 Jan 2019 11:42am
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Your system was designed in 2014. I would look ahead a bit. Buy some lithium batteries.
There's a guy on ebay with prismatic CALB for $120 per 180 amps.
So you would need 8 for a 24v system. Call it $1000 for 4.5kwh of battery. Similar to the older spec of 48v with lead.
However the pack will last far longer. And give you 20% more out of your solar etc. And handle easily the big surge loads from your pump.
Buying a good inverter/charger for 1000. Don't we wish.
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LastOutlaw
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# Posted: 2 Jan 2019 02:41pm - Edited by: LastOutlaw
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Thank you Creeky,
Are you talking about this battery?
https://www.ebay.com/itm/183568098745
And yes Creeky, Ive realized that I'm looking at about 1700 for my inverter that I need.
Also Creeky I've heard that lithium Ion batteries won't charge below freezing temps. Is that correct?
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Wilbour
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# Posted: 2 Jan 2019 04:18pm - Edited by: Wilbour
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The more I read about the two camps, one being the already have lead acid and just want to add to it, and the other taking a fresh look at lithium, the more it sounds like a learning curve.
Lithium doesn't like charging when below freezing so you keep them in your heated space. You set the controller to not charge below freezing and live with he power you have until the cabin heats up.
Lithium costs more but lasts longer and has a greater d.o.d.
This really starts to sound like the gas car vs electric car argument. Both have merit and have to be treated differently.
It's mostly a clean start to go lithium and if you're starting out it's no brainer. If you are clinging onto your older tech because you just cannot afford to dump everything you already have, I get it, but some parts are transferable and others can go on ebay.
I have a great mentor who walked me through a state of the art lithium setup with top notch parts. But not everyone has a guy like that on speed dial.
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LastOutlaw
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# Posted: 2 Jan 2019 05:31pm
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Well this setup is not going into a cabin. In fact it will be in a non heated outbuilding.
I also see that there is a AH loss between these lithium ion batteries at 24 volt and 180 AH rating for $1100
compared to the 24 volt lead acid battery with a 230 AH wired at 460 AH. for $999.00 from Sams.
Now I have to admit I would like to go into the lith ions and we don't get lots of below freezing weather so they are a possibility and drawing more out of them and no maintenance would be quite a bonus.
Now I just found out that Interstate batteries is now carrying Trojans so I'm price shopping those too.
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Wilbour
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# Posted: 2 Jan 2019 05:43pm - Edited by: Wilbour
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Quoting: LastOutlaw Well this setup is not going into a cabin. In fact it will be in a non heated outbuilding
Just so we are clear, the setup is in an outbuilding because that is where you need it?
Li-on users would put them in a heated cabin and send out the power to an outbuilding. Kinda arse backwards thinking in the lead world but like I said, making the shift is just that, a shift in thinking.
Too bad your outbuilding isn't heated. You just may have to keep going in the direction you already are.
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LastOutlaw
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# Posted: 2 Jan 2019 06:03pm
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Because it is close to where my panels need to be...The sunny area.
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offgrididaho
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# Posted: 2 Jan 2019 06:18pm
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Quoting: creeky There's a guy on ebay with prismatic CALB for $120 per 180 amps.
How does one determine proper bulk/absorption/float settings for batteries like this, are they listed on the batt itself or can you find manufacturer spec sheets? And for a 24v system (for example) do you just multiple those voltages by 8?
And am I correct in my reading that these are plug and play (assuming correct wiring gauge etc), no outside BMS or anything?
My issue with lithium is, really, cost still. I can get 8 6v Deka golf cart batteries for $1,150.00 which gives me 11kw/hr, or 5.5kw/hr usable. Everything I've seen up until now would run me $3k+ for a little less than 3.8kw/hr usable. Now even factoring in the increased efficiency and longer life and lower weight, that's just too much (I think) for me to swallow right now.
BUT... if my math is right on the CALB batteries you mention:
https://www.ebay.com/itm/CALB-LIFEPO4-PRISMATIC-SE-SERIES-BATTERY-EV-RV-POWERWALL-3-2 V-170-179-99AH/183568098745
... I could get 8 of those for $1,120 (incl shipping), that gives me 4.3kwh (so ~3.5kwh usable ~ 80% dod). Plus more efficiency and longer life. And the whole pack would weigh less than 2 Deka lead batts.
Things that make you go hmmm...
Do you find this pricing to be a reflection of better overall pricing for these batteries or is this just a screaming deal?
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LastOutlaw
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# Posted: 2 Jan 2019 06:38pm
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These are used and according to the ad came off a hybrid city bus prototype. My concern would be how to insure that they have any good left in them.
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creeky
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# Posted: 2 Jan 2019 11:45pm
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Quoting: offgrididaho 11kw/hr, or 5.5kw/hr usable
Ya. 50% dod. Might want to check the DEKA charts on lifespan. 500 cycles at 50%? So 1.5 years. Now compare that to 10-30 years for the lithium. You won't need a calculator to see which offers the best value.
I would get a BMS. Especially with lifepo4. NMC is stabler. But if you don't want to do a lot of checkin'. Get a good BMS. Not a bike BMS. Still waiting to find a good cheap one.
The advantages of lithium efficiency make such a huge difference. It really is crazy.
There are lots of good deals. I wouldn't worry about use as these cells are designed for 2,000 cycles. So unless the bus prototype is a decade old.
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