road glide
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Have a solar array 2400 watts (10 Talesun 240w 36.9Voc 29.7vmp 8.08 imp 8.62 isc with midnite 250 charge controller with combiner - US split phase. What is recommended for 24v -48vbattery system off grid inverter on the cheap?
What to do with left over 2400W talesun DC Solar rack?
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Hedges
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Cheap could be MPP or Midnight DIY all-in-one. In that case you would likely use the SCC built into it.
However, on eBay you can pick up SMA Sunny Island, mostly $2500 but some recently listed or accepted offer in the $1600 to $1700 range. Slightly higher than 48V Midnight DIY, but very powerful low-frequency inverter, good for 120V off-grid loads. (for 240V, need two inverters or autotransformer.)
Although, maybe you want rain proof inverter?
However, on eBay you can pick up SMA Sunny Island, mostly $2500 but some recently listed or accepted offer in the $1600 to $1700 range. Slightly higher than 48V Midnight DIY, but very powerful low-frequency inverter, good for 120V off-grid loads. (for 240V, need two inverters or autotransformer.)
Although, maybe you want rain proof inverter?
road glide
New Member
I have been reviewing the MPP Solar LV1012 & LV2424. I like the fact off-grid and CT"s not required/needed, almost Plug and Play. But it appears the 2400W is too large of an array. It's 2 rows of 5 panels. 1200 watts per row
. If I remember right, it's five parallel two series. I could use one row, but it's kind of a shame when there's 2400 Watts sitting there. Probably 1600-1800w production.
Hedges
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Cheap enough.
5s2p, not 2s5P presently. Need to rearrange for other voltage limits.
Have to stay under 145V input, so can't keep 5s panel configuration.
But you can if you keep the Midnight 250 and let it charge battery.
Your array wattage is only about 50% over, which is actually about perfect. Tilt half one way, half the other. Better SE and SW rather than E and W, so racks not on the original trailer could be oriented better.
Using the MPP, 5 & 5 would not be the right configuration. Maybe 2s5p (need fuse per string), so 4 facing SE, 4 SW, 2S ?
But 48V could be better than 24V. And I still suggest Sunny Island, unless you don't care about 5750W continuous, 11kW surge.
5s2p, not 2s5P presently. Need to rearrange for other voltage limits.
Have to stay under 145V input, so can't keep 5s panel configuration.
But you can if you keep the Midnight 250 and let it charge battery.
Your array wattage is only about 50% over, which is actually about perfect. Tilt half one way, half the other. Better SE and SW rather than E and W, so racks not on the original trailer could be oriented better.
Using the MPP, 5 & 5 would not be the right configuration. Maybe 2s5p (need fuse per string), so 4 facing SE, 4 SW, 2S ?
But 48V could be better than 24V. And I still suggest Sunny Island, unless you don't care about 5750W continuous, 11kW surge.
road glide
New Member
I just looked at the array on the rack, it's off the trailer on cement pad, since I pirated the other parts (cabinet, batteries)
. Yes, 5s2p as they were originally on the DC Trailer. I used the cabinet with everything inside 2 SI's, MS 250 with combiner, breaker boxes and did a 6400 ground mount with 5kw Sunny Boy AC connect. But this winter in NorCal had absolutely no production.
I have an out building I would like to implement the rack with. I figure I have everything but an inverter, obviously from the DC trailer. But now, most inverters (off-grid, grid, hybrid, AIO) have MPPT built in. Kinda makes the Midnite Solar useless, but I would like to use it if possible...
Looking for a summer project....
. Yes, 5s2p as they were originally on the DC Trailer. I used the cabinet with everything inside 2 SI's, MS 250 with combiner, breaker boxes and did a 6400 ground mount with 5kw Sunny Boy AC connect. But this winter in NorCal had absolutely no production.
I have an out building I would like to implement the rack with. I figure I have everything but an inverter, obviously from the DC trailer. But now, most inverters (off-grid, grid, hybrid, AIO) have MPPT built in. Kinda makes the Midnite Solar useless, but I would like to use it if possible...
Looking for a summer project....
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Hedges
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The classic is as good fit for that string arrangement. 63A into 48V if I remember correctly, so got for a bit more PV watts. With two orientations, even more.
Midnight also has their new Rosie inverter, HF with 8kW output and good surge capability. Not cheap.
Sunny island isn't cheap (MSRP or street price), but the liquidation sales are cheap, a bargain for what you get.
You probably have the shunt for use with Sunny Island. Do the calibration procedure to get it accurate. There is a comms converter for the classic which works with older SI firmware. No need for shunt in that case, but if you use both be sure to connect correctly so it doesn't mis-count current.
Battery is going to be what costs real money.
Midnight also has their new Rosie inverter, HF with 8kW output and good surge capability. Not cheap.
Sunny island isn't cheap (MSRP or street price), but the liquidation sales are cheap, a bargain for what you get.
You probably have the shunt for use with Sunny Island. Do the calibration procedure to get it accurate. There is a comms converter for the classic which works with older SI firmware. No need for shunt in that case, but if you use both be sure to connect correctly so it doesn't mis-count current.
Battery is going to be what costs real money.
road glide
New Member
I own 3 SMA products (2 SI's 6048 & 5kw US Sunny Boy) - very happy with them....I have time...I am going to watch SMA on Ebay, Google etc.
In perfect world...I should have purchased a 6kw Sunny Boy for my ground mount...same wiring requirements and move the 5kw to the building.
But I looked for awhile for 6kw....non existent. Ebay, CL, Facebook quite a few 7kw but takes revamping wiring.
In perfect world...I should have purchased a 6kw Sunny Boy for my ground mount...same wiring requirements and move the 5kw to the building.
But I looked for awhile for 6kw....non existent. Ebay, CL, Facebook quite a few 7kw but takes revamping wiring.
Hedges
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Think you can set maximum wattage of 7kW down to 6kW, if the issue is too much current.
There's one used SI 6048US on eBay for $1600 for pick-up, but I think it is 6 hour drive from you.
Or a new scratch & dent sale for $2100 delivered.
Don't know what prices we'll be seeing from latest round of DC solar auctions.
Thought one of those would be good for your ground mount, with DC coupling.
Were you trying to backfeed grid, or just offgrid or backup?
I'll be waiting for a couple SB 7.7, for new grid-tie install.
There's one used SI 6048US on eBay for $1600 for pick-up, but I think it is 6 hour drive from you.
Or a new scratch & dent sale for $2100 delivered.
Don't know what prices we'll be seeing from latest round of DC solar auctions.
Thought one of those would be good for your ground mount, with DC coupling.
Were you trying to backfeed grid, or just offgrid or backup?
I'll be waiting for a couple SB 7.7, for new grid-tie install.
road glide
New Member
What I saw on SMA spec breakdown is 5kw and 6kw take same awg and 30amp breaker. Once you go above (7KW) heavier wiring and bigger breaker. My building is off grid and that's why those MPP Solar 1012 & 2424 caught my eye. 120v is fine...maybe later do split phase 240v but I doubt it.
LOL...viewing eBay now
PS..I noticed most of those off grid inverters Taiwan have a limit on Volts....150? wattage was ok. Some were 100v....that's only 3 panels
I like your idea turn the rack north and south and let 5 panels face SE and the other 5 face SW....that would probably work with some more arithmetic...
LOL...viewing eBay now
PS..I noticed most of those off grid inverters Taiwan have a limit on Volts....150? wattage was ok. Some were 100v....that's only 3 panels
I like your idea turn the rack north and south and let 5 panels face SE and the other 5 face SW....that would probably work with some more arithmetic...
Hedges
I See Electromagnetic Fields!
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Whatever AC amperage you have coming from grid-tie inverter, thermal-magnetic breaker should be 125% of that, to prevent nuisance trips (due to hot weather and wires heating breaker.)
The Sunny Boy parameters may be in terms of watts not amps. If you divide assumed watts by 240V, amps will likely be that number or less, because utility usually drives line voltage a bit high and it rises higher with inverter backfeeding.
In other words, don't worry about inverter documentation's call for wire and breaker, just dial down output wattage until existing wire and breaker is OK. (Of course, wire ampacity must be sufficient for breaker used.)
I don't know how durable MPP is, but Sunny Boy and Sunny Island are rock solid.
If you're off-grid, then Sunny Island supposedly can manage Sunny Boys up to 2x the wattage of Sunny Island.
I've messed around a bit with transformers between SI and SB (or TriPower), can off advice if you try it.
MPPT will take the place of your math, although with math you can estimate how much clipping and extended hours.
My plan is to put 15kW of PV panels on one 7.7kW SB for my sister's house.
Midnight has SCC for 150, 200, 250, and now 600V.
But if you're off-grid, you don't have to get SB -41 for its grid features. Look for earlier transformerless or the transformer type 5000 ~ 8000US. Just set them for offgrid (no RS-485 interface needed for use like in backup systems, just use to configure.) That series can have PV array negative or positive grounded, preventing "PID" for panels which are more susceptible. I've bought older SB for $0.10/W.
The Sunny Boy parameters may be in terms of watts not amps. If you divide assumed watts by 240V, amps will likely be that number or less, because utility usually drives line voltage a bit high and it rises higher with inverter backfeeding.
In other words, don't worry about inverter documentation's call for wire and breaker, just dial down output wattage until existing wire and breaker is OK. (Of course, wire ampacity must be sufficient for breaker used.)
I don't know how durable MPP is, but Sunny Boy and Sunny Island are rock solid.
If you're off-grid, then Sunny Island supposedly can manage Sunny Boys up to 2x the wattage of Sunny Island.
I've messed around a bit with transformers between SI and SB (or TriPower), can off advice if you try it.
MPPT will take the place of your math, although with math you can estimate how much clipping and extended hours.
My plan is to put 15kW of PV panels on one 7.7kW SB for my sister's house.
Midnight has SCC for 150, 200, 250, and now 600V.
But if you're off-grid, you don't have to get SB -41 for its grid features. Look for earlier transformerless or the transformer type 5000 ~ 8000US. Just set them for offgrid (no RS-485 interface needed for use like in backup systems, just use to configure.) That series can have PV array negative or positive grounded, preventing "PID" for panels which are more susceptible. I've bought older SB for $0.10/W.
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