Trying to Pick all in 1 invertor for ~2kw array built w/ used panels.

[donaldbitterman]

Hello,

I am have 18 used 120 watt panels and would like to get these grid tied and for a dream system have battery back up. My electrical usage is very low so in reality I could get away w/ a 1.2 kw array.

I have in hand a SolarEdge 5000a (unknown if it works) but want to sell that off as untested/parts only as it is oversized and I would rather not go through the step of getting microinverters etc. Selling it and cutting out at least one unknown is a preferred option.

Watching Will and others videos as well as digging through these forums I am thinking of going w/ the a 1000 watt inverter below:

PIP-1012LV-MS – 12V 120VAC 1000W AC output, 500W Max 40A Mppt Solar Input – Watts247 Wholesale

watts247.com

The inverter is a bit undersized, but I have other uses for any extra panels and would love to add battery as well.

I'm also looking at the 2kv system below:

Overstock – PIP-2024LV-MK 24V 2kW, Inverter and 2kW Solar Charge controller Parallel-able Split Phase option- Zero Transfer Time! – Watts247 Wholesale

watts247.com

This may be the better option, but I am really unsure if going this is the best path.

A few questions:
1. Can I use this in a permitted grid tie system (not sure on UL listings, etc)
2. Are these the best option
3. As long as I don't exceed input voltage is there any issue with have more panels than the inverter is rated for?
4. Is this outdoor rated? If not, I have a MCC NEMA rated cabinet I can mount this in.

Any other recommendations or should I go with a different unit?

 

[Maast]

This one would be a better choice, and I'd avoid 12v systems unless you're in a vehicle of some sort that needs to interface with the charging system. However I don't believe its UL listed but I'm not sure. I wouldnt touch a MPP with a 10 foot pole, they have a horrific self-consumption.

SPF 3000TL LVM-ES 3kW 120V, 120 to 250V Solar Voltage, 48V Battery OPTIONAL (batteryless), up to 6 in parallel for single , split or 3 phase output – + free wifi – Watts247.com

watts247.com

Edit, according to the below they are UL listed:

Growatt

 

[donaldbitterman]

This one would be a better choice, and I'd avoid 12v systems unless you're in a vehicle of some sort that needs to interface with the charging system. However I don't believe its UL listed but I'm not sure. I wouldnt touch a MPP with a 10 foot pole, they have a horrific self-consumption.

SPF 3000TL LVM-ES 3kW 120V, 120 to 250V Solar Voltage, 48V Battery OPTIONAL (batteryless), up to 6 in parallel for single , split or 3 phase output – + free wifi – Watts247.com

watts247.com

Edit, according to the below they are UL listed:

Growatt

Thanks Maast!

As I am reading a bit more about these, one concept that slipped by is that both these MPP and Growatts are "Grid Assist", meaning that one cannot put power out to the grid.

They seem to serve more as a BMS/Inverter (for power from your battery bank to house side power)/ and automatic transfer switch in one (which is neat, but I was hoping to do a grid tie for this system).

I was hoping for something low cost / rated for 1-2 kw that would serve as a actual grid tie inverter, but am not having luck finding anything below the 1,000 price point. There are some on amazon, but none seem to be UL etc rated and thus I can't use

 

[Maast]

Thanks Maast!

As I am reading a bit more about these, one concept that slipped by is that both these MPP and Growatts are "Grid Assist", meaning that one cannot put power out to the grid.

They seem to serve more as a BMS/Inverter (for power from your battery bank to house side power)/ and automatic transfer switch in one (which is neat, but I was hoping to do a grid tie for this system).

I was hoping for something low cost / rated for 1-2 kw that would serve as a actual grid tie inverter, but am not having luck finding anything below the 1,000 price point. There are some on amazon, but none seem to be UL etc rated and thus I can't use

If you want to sell to the grid the price is going to go up and you start looking at brands like Magnum or Outback or Sol-Ark as there are strict regulatory requirements and certifications an inverter has to have first. Personally I have a Outback Radian GS8048A-1 and it's a hell of a inverter, but I paid a premium for it, mainly for their 'it just works' reliability and its maintainability.

 

[Bud Martin]

Ddi you ask your utility supplier and your city as to the cost and the permit/inspection if you want to feed the power back into the grid?

 

[donaldbitterman]

Ddi you ask your utility supplier and your city as to the cost and the permit/inspection if you want to feed the power back into the grid?

I did talk to the city and it is $235. They will let accept a permit package and non stamped drawing set.

I have not called the utility (PG&E, this is northern CA), looking on line I see reference to a $145 fee, but on PG&E's site it looks like they don't charge an initial connection fee. I will call them though and clarify this detail!!

I am in a community choice aggregator that offers a bit more favorable terms for net metering than if I went direct with the utility (PG&E).

Link is below:
https://www.mcecleanenergy.org/

Great question, I was only thinking of the city permit fees!

 

[Bud Martin]

I live in north bay also, it can add up quite a bit.

 

[donaldbitterman]

If you want to sell to the grid the price is going to go up and you start looking at brands like Magnum or Outback or Sol-Ark as there are strict regulatory requirements and certifications an inverter has to have first. Personally I have a Outback Radian GS8048A-1 and it's a hell of a inverter, but I paid a premium for it, mainly for their 'it just works' reliability and its maintainability.

Outback looks like it is ~$3,700 for 8 kw, Sol-Ark looks like $7,000 for 12 kw

The Magnum inverter you mention looks like they have some microinverter options, that may be the ticket to make this pan out!!! I'll be doing a bit more digging on microinverter options. It looks like Enphase may also be a good path!

Looking at this thread there is mention of these offbrand microinverters, I wonder if that may be an option that could actually get permitted?
Thread link:

Grid Tie Micro Inverter

This is about as simple as it gets. Panel, inverter, plug. I have four, for the panels I have. I'll be putting one on, most likely today. Amazon https://www.amazon.com/dp/B08CMLBLLJ/ref=cm_sw_r_tw_dp_x_wLtXFbAAWJFZ3 Aliexpress...

diysolarforum.com

Microinverter link

43.48US $ 20% OFF|Mppt Solar Grid Tie Micro Inverter 260w 300w 350w 500w 600w Dc18v-50v To Ac110v-230v 50hz/60hz Solar Pv Inverter Waterproof Ip55 - Inverters & Converters - AliExpress

Smarter Shopping, Better Living! Aliexpress.com

www.aliexpress.com

or these "SG series"

72.88US $ 12% OFF|400W 450W 500W 600W 700W PV Smart Micro inverter MPPT Grid Tie Inverter Input 18 50VDC to 100V 240VAC with monitoring Collector|Inverters & Converters| - AliExpress

Smarter Shopping, Better Living! Aliexpress.com

www.aliexpress.com

I may be going way off track as there is no way these are UL listed or anything, but that would be bananas if I could go grid tie this cheap.

 

[donaldbitterman]

I live in north bay also, it can add up quite a bit.

Hopefully the $235 the city wants is it, it pains me to spend on anything not equipment related!

 

[Bud Martin]

Hopefully the $235 the city wants is it, it pains me to spend on anything not equipment related!

I am not sure if this is true or not, I was told that you can perform the wiring yourself but you have to to get it signed off by licensed electrician then the city inspector will then come out to inspect the work before signing off the approval.

 

[Hedges]

Instead of giving the city $235, you could give this company $286 for zero-backfeed (follow the link in this posting)

Planning to reduce electric bill by solar push, no feed back to grid. Daylight hours only.

Here's my thoughts, I have a swamp cooler to cool my home (mobile home), it uses 222 watts when running on low, 120 volt, 440 watts on high. Fridge uses 125 watts when it kicks on, 4.24 KWH in 48 hours time, no big deal. I want to purchase 2x 100 watt panels, and a 600 watt, grid tie inverter...

diysolarforum.com

I don't know how good it is, but this should let PV supply your house (while the grid is up) without feeding the grid.

I am not sure if this is true or not, I was told that you can perform the wiring yourself but you have to to get it signed off by licensed electrician then the city inspector will then come out to inspect the work before signing off the approval.

Maybe some states, not California. We can do our own.

 

[donaldbitterman]

Instead of giving the city $235, you could give this company $286 for zero-backfeed (follow the link in this posting)

Planning to reduce electric bill by solar push, no feed back to grid. Daylight hours only.

Here's my thoughts, I have a swamp cooler to cool my home (mobile home), it uses 222 watts when running on low, 120 volt, 440 watts on high. Fridge uses 125 watts when it kicks on, 4.24 KWH in 48 hours time, no big deal. I want to purchase 2x 100 watt panels, and a 600 watt, grid tie inverter...

diysolarforum.com

I don't know how good it is, but this should let PV supply your house (while the grid is up) without feeding the grid.




Maybe some states, not California. We can do our own.

Thanks Hedges!

This gets back to the "grid assist", I am going to add something like that as a phase 2 (I have an electrodacus and want to build this out as a system that I could potentially hot swap between loads on my house and also take out w/ a camper............that is getting too far down the road.

That does seem like a great system that you linked to! There is allot more to this than I thought.

Currently my scheme is looking like:

Phase 1:
Take the 18 120 W panels
Use enphase microinverters (maybe get used off of ebay) and maybe the envoy (think I could get away without that, but need to research).

Do a permit grid tie, make it as legitimate as possible

Phase 2:
Build out the Electrodacus system for use when camping, blackouts, try to make it so when I am not traveling as much of the house load is using that system.

 

[Hedges]

I think some but not all models of Enphase microinverters support frequency-watts control of output power. Those which do should be able to interact with a battery inverter that supports AC coupling. This could make a nice battery backup.

String inverters can do the same thing. They may require RSD box per panel.

Some Hybrids (Sol Ark, etc.) DC couple panels, can backfeed the grid (maybe do zero-export as well?) and run with batteries off-grid. Likely require RSD.

If you do a permitted grid-tie and are allowed backfeed, then no benefit to a zero-backfeed system.
Depending on utility rules, you might want to enable loads so you use power when you make it, if they don't give 100% credit.

I also have 120W panels, presently ground-mount. If I moved them to roof mount I would string 3 in series and wire that to RSD. I saw some RSD which accept 4 panels, so would work with 3 x 4 = 12 of my 120W panels. Two of those RSD would give me 24 panels in series, which is how I use them with < 600Voc string inverters.

 

[Hedges]

If a permitted grid-tie system, probably has to comply with UL-1741SA.
Older inverters from eBay might only be UL-1741, not "SA", so may not be allowed for new permits in your location.

I get to use them because I'm replacing older, permitted inverters.

This is one of the reasons you might do a zero-export system. I think you can build a UPS for critical loads or whole house, zero export and not required to comply with the new grid-support rules.

 

[donaldbitterman]

If a permitted grid-tie system, probably has to comply with UL-1741SA.
Older inverters from eBay might only be UL-1741, not "SA", so may not be allowed for new permits in your location.

I get to use them because I'm replacing older, permitted inverters.

This is one of the reasons you might do a zero-export system. I think you can build a UPS for critical loads or whole house, zero export and not required to comply with the new grid-support rules.

Hedges,

Thank you, you have given me allot to think about. I keep leaning away from the zero export system as this is a home I will likely sell in 3-5 years or rent out. This is not certain and I really want to do something.

If it was a long term house I would 100% go the route you went.

Still not sure, going to read, consider, and pencil out numbers more!

Thanks again Mr. Hedges!!

 

[donaldbitterman]

If a permitted grid-tie system, probably has to comply with UL-1741SA.
Older inverters from eBay might only be UL-1741, not "SA", so may not be allowed for new permits in your location.

I get to use them because I'm replacing older, permitted inverters.

This is one of the reasons you might do a zero-export system. I think you can build a UPS for critical loads or whole house, zero export and not required to comply with the new grid-support rules.

Hedges,

I added up the numbers for a compliant Enphase system, it would be 1,200 just for inverters and the envoy, then permits, etc. etc. Much to my chagrin, even w/ DIY a compliant grid tie system just is not economically viable. This is a 3 person single family home, we just don't use allot of power. Maybe if I ever get a ev or something, then it would pan out.

You are right, grid export is just not worth it for my usage case.

I think the non export system is the only path and I have to justify that w/ non economic factors (fun & learning of building the system, green example to kids, availability of system when the grid goes down, etc.).

 

[Bud Martin]

You use about the same amout of power as I do here in north bay.
I built my 1000W solar system last Septhember for learning experience after stumbling into Will's video while looking for the review of generator from COSTCO to prepare myself for PG&E rolling black out, the system is saving me only around $25 a month but the knowledge I get from it is worth way lots more than that and I have fun building it too..

 

[Hedges]

Hedges,

I added up the numbers for a compliant Enphase system, it would be 1,200 just for inverters and the envoy, then permits, etc. etc. Much to my chagrin, even w/ DIY a compliant grid tie system just is not economically viable. This is a 3 person single family home, we just don't use allot of power. Maybe if I ever get a ev or something, then it would pan out.

You are right, grid export is just not worth it for my usage case.

I think the non export system is the only path and I have to justify that w/ non economic factors (fun & learning of building the system, green example to kids, availability of system when the grid goes down, etc.).

Yes, more difficult to be cost-effective for a smaller system and with only new equipment being compliant.
$1200/2000W = $0.60/W just for inverters.

Microinverters (e.g. Enphase) do let you scale it to your PV capacity, but with inverter per panel either each inverter is under-utilized or over-paneled. Over-paneled could be the way to go.

"18 used 120 watt"
Did you price 18 Enphase micro inverters?
See if three, 120W panels in series would remain within its voltage limits (or some other series/parallel combination e.g. 2s2p)
Does the price look much better with just 6 microinverters?
I'm not sure Envoy is required, especially if just basic grid tie without monitoring or control.

With a string inverter, the combination of panels can more closely fit inverter capacity. Except, 2000W is small. Inverters are typically 3kW to 7.7kW. I have bought inverters for $0.10/W both new and used, older models that aren't UL-1741SA. The new models compliant to latest code cost about $0.25/kW. If Rapid Shutdown is required, that is additional hardware.

The panels you already have are free, but newer second-hand panels in the 300W to 500W range are attractive because they save on mounting hardware costs and labor.

If you build a battery-backup system that keeps internet and refrigerator going during a power outage you will spend more but it provides other value. Battery to run fridge at night is large and expensive, so size it to supply just telecom and other critical loads, plug refrigerator into it with a timer so fridge only runs when sun is on the panels. Take it with you to your next house. Maybe mount the panels on a patio roof, replace with roofing material when you move.

 

[donaldbitterman]

Yes, more difficult to be cost-effective for a smaller system and with only new equipment being compliant.
$1200/2000W = $0.60/W just for inverters.

Microinverters (e.g. Enphase) do let you scale it to your PV capacity, but with inverter per panel either each inverter is under-utilized or over-paneled. Over-paneled could be the way to go.

"18 used 120 watt"
Did you price 18 Enphase micro inverters?
See if three, 120W panels in series would remain within its voltage limits (or some other series/parallel combination e.g. 2s2p)
Does the price look much better with just 6 microinverters?
I'm not sure Envoy is required, especially if just basic grid tie without monitoring or control.

With a string inverter, the combination of panels can more closely fit inverter capacity. Except, 2000W is small. Inverters are typically 3kW to 7.7kW. I have bought inverters for $0.10/W both new and used, older models that aren't UL-1741SA. The new models compliant to latest code cost about $0.25/kW. If Rapid Shutdown is required, that is additional hardware.

The panels you already have are free, but newer second-hand panels in the 300W to 500W range are attractive because they save on mounting hardware costs and labor.

If you build a battery-backup system that keeps internet and refrigerator going during a power outage you will spend more but it provides other value. Battery to run fridge at night is large and expensive, so size it to supply just telecom and other critical loads, plug refrigerator into it with a timer so fridge only runs when sun is on the panels. Take it with you to your next house. Maybe mount the panels on a patio roof, replace with roofing material when you move.

Hedges,

On roof mounting: I have a flat roof that I just put an elastomeric coating on. I am thinking of going with a ballasted flat roof mount, going to read about it then start getting a few quotes from Alibaba. The pricing is not really transparent, and if it is too much of a headache I'll just rig up my own, but I am trying to save a bit of time as there is much to do!

Flat Roof Ballast-Flat Roof Ballast Manufacturers, Suppliers and Exporters on Alibaba.comSolar Mounting System

Flat Roof Ballast Manufacturers & Flat Roof Ballast Suppliers Directory - Find a Flat Roof Ballast Manufacturer and Supplier. Choose Quality Flat Roof Ballast Manufacturers, Suppliers, Exporters at Alibaba.com.Solar Mounting System

www.alibaba.com

I am thinking labor and hardware costs will be fairly minimal with this approach and the size of the array is not a issue as it is "wasted space"

Photo of my roof in thread below

DIY Grid Tie System 2 KW

Hello, I recently bought 18 120W panels and a Solaredge 5000a (I think, no tag on unit) for $150 total. My power usage has always been relatively low (table w/ power & cost below) so I couldn't justify a solar system financially but I think going this way will let me pull it off. My roof is...

diysolarforum.com

On the inverter/charge controler, etc: I was leaning towards the enphase only in context of doing a legal grid tie system, since this is not going that way, I am thinking now to go I already have an electrodacus system that I have just not hooked up yet
Photos of enclosure, mock up, batteries, etc below:

https://www.instagram.com/p/CHWCb7kpcJD/?igshid=1bjt5oul1cpox

On the Batteries: I have ~1,500-2,000 (need to get a good count) 18650's and most of the hardware/tools needed to build them into packs. I just need to go through the process of actually sorting/processing them. I am almost leaning towards selling these and using the funds for LiPO4 cells just for the the safety aspect.

A few considerations:
1. Figure out how to practically use the power from this system throughout at least some of the house

2. See if there is some way to use excess power as this will be a system that is generating more than I use, and if I go through with assembeling the 18650's into packs I think I can have a system with an oversize battery array and power generation. My thought is maybe get a crypto miner and run it DC linked to the battery pack. Rigging up something to heat water in my water heater is another. This is getting way too far out, and I need to wrap up phase 1 which is get this system up an running. Phase 2 is get it to some of the house. Phase 3 would be practical applications for cheap unneeded power.

 

[donaldbitterman]

You use about the same amout of power as I do here in north bay.
I built my 1000W solar system last Septhember for learning experience after stumbling into Will's video while looking for the review of generator from COSTCO to prepare myself for PG&E rolling black out, the system is saving me only around $25 a month but the knowledge I get from it is worth way lots more than that and I have fun building it too..

Yup, when AC is not really needed and with minor conservation efforts it is not hard to drop electrical usage low. It's one of the blessings of living in this area! I am almost glad the black outs occurred for selfish reasons, now I really have a great excuse to build the system out