Hello everybody... I currently live off grid in northern California and have been making do the last several years with a hodgepodge of recycled 12v panels and batteries. A local was replacing his grid tied system and I ended up with the old system... now I am trying to figure out what to do with it and any guidance would be appreciated. My current systems feed about 1000watts 12v to two sets of ancient batteries (4) 6v trojan 400amp/hr and (4) 6v rolls 300 amp/hr What I got is ~5kw of panels (30) 198 watt 32.9v (voc) 26.3v (vpm) 7.52a (lpm) Sharp ND-198U1F circa 2008 also a grid tie inverter [sunny boy SB5000US PV ] which I don't think there is any use for offgrid without some serious hacks. Anyway the initial thought is to divide these into two systems (12 panels 24v) (18 panels 24v) and get some new2me batteries, new2me charge controller. My set up in the woods isn't much more than a container house at the moment so not a lot of needs yet though in the future a couple cabins and pond pumps and filters. Any thoughts on how best to configure these would be great! Thanks ~ RL
I acquired 30 used panels and trying to figure out the best use for them.
- Thread starter RightLane
- Start date
schmism
Solar Addict
I wouldn't try to use the inverters.
My suggestion is a growatt/MPP hybrid inverter. A single 3kw 48v spf3000tl (growatt) will be slightly over panneled (per sticker specs) with all the panels. But it may not be an issue based on shade amount (Being in the woods) and or older used panels. That unit will give you 3kw output for future expansion. You can also add additional parallel inverters in the future for additional power.
Id recommend LFP if your replacing the battery pack. That inverter will support FLA but managing all 8 used FLA batteries in series will be a challenge.
they make a 24v verison also however only supports half the solar input (so you'd need 2)
My suggestion is a growatt/MPP hybrid inverter. A single 3kw 48v spf3000tl (growatt) will be slightly over panneled (per sticker specs) with all the panels. But it may not be an issue based on shade amount (Being in the woods) and or older used panels. That unit will give you 3kw output for future expansion. You can also add additional parallel inverters in the future for additional power.
Id recommend LFP if your replacing the battery pack. That inverter will support FLA but managing all 8 used FLA batteries in series will be a challenge.
they make a 24v verison also however only supports half the solar input (so you'd need 2)
MichaelK
Solar Wizard
What I would do is trade in all the batteries, and buy eight new ones to create a 48V system. Here's the Rolls battery that I'm using right now.
www.rollsbattery.com
They also make an 8V version of the same capacity, but twice as heavy. You'd pay about 600$ less for a 48V system made from the 8V, compared to the 4V.
You could then get a new MPPT controller that operates at 200-250V. I am currently using Midnight's 200V CC. You can take your 26V panels and put them in series for a 4S7P set of arrays. Alternatively, 6S5P, but only with a 250V charge controller. You can build array frames like mine in the pic. I put 4 panels on it in portrait orientation, though you could mount 6 in landscape orientation.
If operating a high voltage, you are free to place your arrays in the best solar spots up to hundreds of feet from your location. What I've done is position different arrays to optimize solar power in early morning, noon, or late afternoon.
I'd couple that with a good split-phase 120/240VAC inverter so you can wire a standard house panel for either 120 or 240V appliances. I have a Schneider XW6848 to run my 240VAC well-pump that way. You can have pumped water, refrigeration, air-conditioning, ect
4 CS 17P | Rolls Battery
You could then get a new MPPT controller that operates at 200-250V. I am currently using Midnight's 200V CC. You can take your 26V panels and put them in series for a 4S7P set of arrays. Alternatively, 6S5P, but only with a 250V charge controller. You can build array frames like mine in the pic. I put 4 panels on it in portrait orientation, though you could mount 6 in landscape orientation.
If operating a high voltage, you are free to place your arrays in the best solar spots up to hundreds of feet from your location. What I've done is position different arrays to optimize solar power in early morning, noon, or late afternoon.
I'd couple that with a good split-phase 120/240VAC inverter so you can wire a standard house panel for either 120 or 240V appliances. I have a Schneider XW6848 to run my 240VAC well-pump that way. You can have pumped water, refrigeration, air-conditioning, ect
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Sounds like this will be quite a move up in power for you, congrats.
You don't mention your current charge controller or inverter, so I am guessing they don't exist and you are running everything now at 12VDC; is that right? Are you looking to continue doing that, or were you thinking of moving everything over to 120/240VAC?
Depending on your answers to these questions, your new system(s) would look very different. Assuming you don't have a need to keep some 12VDC stuff running any more (or you can do that off a voltage converter from a higher voltage batt bank), getting an inverter and possibly a separate charge controller(s) would be the way to go, IMO. It isn't clear to me why you'd split these panels into two systems; are there placement considerations and/or a need to power two separated structures? Which inverter(s) probably depends on what your future needs are, any big draw things you will be running someday (water pumps, AC, etc), and to some extent what features you want, built-in MPPT controller, generator ready, etc. In general, getting one larger inverter for a single system is going to be less costly than two separate ones.
I'd probably agree that getting a new matched set of batts is the way to go, unless finances are really strapped or you old batts are relatively new and still have a lot of life left in them, but even then...
WIth MPPT controllers, you can put enough panels in series to get the voltage up so that wire size and wire run losses are under control. That is basically regardless of what batt voltage you choose. But a 48v system will make for smaller wiring on all of the DC side to/from batts and inverter.
As with any system design, an awful lot depends on what you want to do, now and in the future. And of course the details of your site. If you could give us a list of your current needs and future wants it would likely help folks here point you to some products that meet those.
FWIW, I am using a set of similar 167W Sharp panels of that vintage. They are still going strong and will on occasion still put out more than their rated wattage; so I think you will do well with them.
Good luck.
You don't mention your current charge controller or inverter, so I am guessing they don't exist and you are running everything now at 12VDC; is that right? Are you looking to continue doing that, or were you thinking of moving everything over to 120/240VAC?
Depending on your answers to these questions, your new system(s) would look very different. Assuming you don't have a need to keep some 12VDC stuff running any more (or you can do that off a voltage converter from a higher voltage batt bank), getting an inverter and possibly a separate charge controller(s) would be the way to go, IMO. It isn't clear to me why you'd split these panels into two systems; are there placement considerations and/or a need to power two separated structures? Which inverter(s) probably depends on what your future needs are, any big draw things you will be running someday (water pumps, AC, etc), and to some extent what features you want, built-in MPPT controller, generator ready, etc. In general, getting one larger inverter for a single system is going to be less costly than two separate ones.
I'd probably agree that getting a new matched set of batts is the way to go, unless finances are really strapped or you old batts are relatively new and still have a lot of life left in them, but even then...
WIth MPPT controllers, you can put enough panels in series to get the voltage up so that wire size and wire run losses are under control. That is basically regardless of what batt voltage you choose. But a 48v system will make for smaller wiring on all of the DC side to/from batts and inverter.
As with any system design, an awful lot depends on what you want to do, now and in the future. And of course the details of your site. If you could give us a list of your current needs and future wants it would likely help folks here point you to some products that meet those.
FWIW, I am using a set of similar 167W Sharp panels of that vintage. They are still going strong and will on occasion still put out more than their rated wattage; so I think you will do well with them.
Good luck.
Thank you all for chiming so far...
I am definitely open to getting new batteries, I simply have been putting that off as long as possible to let technology make a few leaps. The main batteries I list above are approaching 15 years or more of service. Maybe the lifpoe battleborn or some such custom lithium build, though I get snow here about 2-3 weeks a year and would probably be better served value and performance wise with sealed lead carbon? I looked into salt water based batteries though they seem to not be as featured locally as they were for a while.
As far as the hodgepodge goes this is certainly a big wattage upgrade… I have a few options currently
I have several low end charge controllers simple 20amp sunguard and some 40amp and 100amp mppt which are self sensing 12v or 24v I have a couple 12v inverters 1000 and 2000 watts and one 1500 watt 24v inverter as well. I basically have 3 small systems I use to recharge tool batteries, charge laptops and run basic appliances when needed. Most of my lighting is rechargeable 5v. led. so not tied to staying 12v though it is preferable. I don't have a generator at least not a fossil fuel one (gas or propane) I do have a spin bike that I can charge 12v with or potentially from the car alternator. I would like to keep the costs down though I realize bumping up the KWH's and watts means replacing some of my existing tech collection.
The idea of higher voltage could be a good line to follow for it would allow me to place the panels at a spot with full sun 9am to 7pm most of the year. Say up to 200' run to areas of use. The array as installed before (as grid tied) seems to have been 3 sets of 10 240v 21 amps though I am not sure.
Now at present I have a CNC machine down at a neighbors that is on the grid, if I could get enough power to run that up here, that would be great as well. Say a small sunny day use wood shop barn set up with plug in power tools. That could maybe justify a different inverter/charge controller (Presently all my tools are 18v and 20v battery)
if I do go with two systems from the panels one set of panels will go to my neighbors to help them out since they don't make it through winter with their existing 9 panels without a generator . they have an outback flexmax60 pv mppt charge controller. (thus my idea of 12 for panels them and 18 panels for me)
As far as the sunny boy SB5000US PV grid tie inverter… tricking it to think it was tied to the grid seems to be a hack people have done, though wisdom says I'd be better served if I could maybe just sell or trade it… A person not to far from me has them listed for sale for $750 refurbished, this one is still in working order so it should be worth something at least that might get me toward a good offgrid charge controller/inverter.
I am definitely open to getting new batteries, I simply have been putting that off as long as possible to let technology make a few leaps. The main batteries I list above are approaching 15 years or more of service. Maybe the lifpoe battleborn or some such custom lithium build, though I get snow here about 2-3 weeks a year and would probably be better served value and performance wise with sealed lead carbon? I looked into salt water based batteries though they seem to not be as featured locally as they were for a while.
As far as the hodgepodge goes this is certainly a big wattage upgrade… I have a few options currently
I have several low end charge controllers simple 20amp sunguard and some 40amp and 100amp mppt which are self sensing 12v or 24v I have a couple 12v inverters 1000 and 2000 watts and one 1500 watt 24v inverter as well. I basically have 3 small systems I use to recharge tool batteries, charge laptops and run basic appliances when needed. Most of my lighting is rechargeable 5v. led. so not tied to staying 12v though it is preferable. I don't have a generator at least not a fossil fuel one (gas or propane) I do have a spin bike that I can charge 12v with or potentially from the car alternator. I would like to keep the costs down though I realize bumping up the KWH's and watts means replacing some of my existing tech collection. The idea of higher voltage could be a good line to follow for it would allow me to place the panels at a spot with full sun 9am to 7pm most of the year. Say up to 200' run to areas of use. The array as installed before (as grid tied) seems to have been 3 sets of 10 240v 21 amps though I am not sure.
Now at present I have a CNC machine down at a neighbors that is on the grid, if I could get enough power to run that up here, that would be great as well. Say a small sunny day use wood shop barn set up with plug in power tools. That could maybe justify a different inverter/charge controller (Presently all my tools are 18v and 20v battery)
if I do go with two systems from the panels one set of panels will go to my neighbors to help them out since they don't make it through winter with their existing 9 panels without a generator . they have an outback flexmax60 pv mppt charge controller. (thus my idea of 12 for panels them and 18 panels for me)
As far as the sunny boy SB5000US PV grid tie inverter… tricking it to think it was tied to the grid seems to be a hack people have done, though wisdom says I'd be better served if I could maybe just sell or trade it… A person not to far from me has them listed for sale for $750 refurbished, this one is still in working order so it should be worth something at least that might get me toward a good offgrid charge controller/inverter.
The panels came with the rack system so I just need the roof to put them on . I want to proceed with getting 4 new batteries. (Since one of the 6v trojans is down a cell now) After years of using 6v and myself and others having whole systems go down for one bad battery I think (4) 12v is the way to go for me. if I go with a charge controller that can do 12v, 24v, 48v I will have more flexibility. If that sounds logical the next question is type and how many amp hours I can afford.
. I want to proceed with getting 4 new batteries. (Since one of the 6v trojans is down a cell now) After years of using 6v and myself and others having whole systems go down for one bad battery I think (4) 12v is the way to go for me. if I go with a charge controller that can do 12v, 24v, 48v I will have more flexibility. If that sounds logical the next question is type and how many amp hours I can afford.
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