My panels have too much voltage

[JoshuaC0352]

Greetings everyone. I am new to all of this, including this forum, so please be patient with me. I have run into an issue. I ordered a battery from BigBattery.com, and the battery came with a home install kit. The kit included a Growatt 6000 inverter. All of this has been shipped, and is supposed to arrive today. However, when I was reading the manual for the Growatt inverter, it says the max voltage it can handle is 240v. My panels (which were on the house when I bought it, so it's not my fault) generate 365-370 volts. So now I am in a dilemma. I checked online and there is a European inverter that has been modified to be compatible with the US grid. It can handle up to 450 volts. But that means I would have to return my current inverter (which is better than the European one BTW, because it can push out 6kw compared to the 5kw of the Euro one). I don't know if I can return the current one though, since I bought it as a package from BigBattery.com. I'm trying to get a hold of them right now. So I have two options as far as I understand it. I can split the PV-DC line and split the voltage, and send 270v to the inverter that came with the panels (that inverter is rated for 270-500), and send 100v to the Growatt 6000. This would require me to build some complicated system involving resistors and such, which will still cost me additional money. Or I could buy the modified European Growatt 5000 and just use that one. I was just wondering what you guys think the best course of action should be. Also, here is some additional info:

Big Battery: 15kwh - 7kw
Current Inverter: 270v - 500v (dumb inverter. Just converts DC to AC) - This pushes power straight back to the grid.
Growatt 6000 - US inverter, 60-240v DC input, output 6kw (smart inverter)
Growatt 5000 - European build, modified for US grid, up to 450v DC input, output 5kw (smart inverter)
Panels: 370v and 0-4kw

edit: Just got done talking with BigBattery, they will not allow me to return the inverter. So I will have to use the Growatt6000 or see if I can re-sell it.

 

[John Frum]

Please include a product link to your Growatt so that we can verify the PV limit.
240 volts sounds like the specification for the AC side not the PV side.

 

[JoshuaC0352]

Please include a product link to your Growatt so that we can verify the PV limit.
240 volts sounds like the specification for the AC side not the PV side.

Growatt 6K Inverter - BigBattery.com

Growatt SPF 6000 DVM series off grid solar inverter is integrated with a MPPT solar charge controller, 120 VAC split phase output , Transformer design provides reliable power conversion in compact size.

bigbattery.com

 

[JoshuaC0352]

Here is the manual

 

[John Frum]

Growatt 6K Inverter - BigBattery.com

Growatt SPF 6000 DVM series off grid solar inverter is integrated with a MPPT solar charge controller, 120 VAC split phase output , Transformer design provides reliable power conversion in compact size.

bigbattery.com

Looks like the pv side has a max of 245VDC.

 

[JoshuaC0352]

Please include a product link to your Growatt so that we can verify the PV limit.
240 volts sounds like the specification for the AC side not the PV side.

On page 10 of the manual it talks about the max PV array open circuit voltage

 

[camelCase]

Also, please give the model number and count of panels in your array.

 

[JoshuaC0352]

Here is the Growatt5000

Growatt 5kW Stackable Off-Grid Inverter | SPF 5000 ES-US (PRE-ORDER)

Signature Solar provides solar components and full kits for off-grid, grid-tie and custom diy solar systems. Providing Solar 101 and hands on experience within the solar industry. Quality inverters, bifacial solar panels, complete solar kits, solar batteries. Holding best in class brands such as...

signaturesolar.com

 

[JoshuaC0352]

Also, please give the model number and count of panels in your array.

The panels were on the house when I bought it, and the previous owner didn't pass any information on to me. I would have to climb up on the roof and count the panels. I know they produce near 4kw, because the inverter reports how much power it is getting.

 

[Hedges]

High voltage battery charge controllers tend to cost more, so understandable a battery based all in one has lower max PV voltage.
An expensive brand, Sol-Ark, takes high voltage PV.

There are separate 600V SCC, but not cheap.

Given existing GT PV, you may be able to keep that inverter and AC couple to a battery inverter (if existing one does UL-1741-SA frequency-watts not just UL-1741)

Only 4kW of PV?
Cheapest solution may be to replace with different panels. Surplus/used market has dried up with recent demand, but would expect that to change in the future.

 

[JoshuaC0352]

High voltage battery charge controllers tend to cost more, so understandable a battery based all in one has lower max PV voltage.
An expensive brand, Sol-Ark, takes high voltage PV.

There are separate 600V SCC, but not cheap.

Given existing GT PV, you may be able to keep that inverter and AC couple to a battery inverter (if existing one does UL-1741-SA frequency-watts not just UL-1741)

Only 4kW of PV?
Cheapest solution may be to replace with different panels. Surplus/used market has dried up with recent demand, but would expect that to change in the future.

You're talking a bit over my head here, but I did post an inverter that can handle up to 450v that only cost $900. As far as replacing the panels, I don't have the money to do that. I blew all of my liquid funds on the battery, so I will have to start saving up again.

 

[camelCase]

Why not rewire the array to split series/parallel for half the voltage? It would double the amperage and possibly require heavier cabling.

 

[JoshuaC0352]

Why not rewire the array to split series/parallel for half the voltage? It would double the amperage and possibly require heavier cabling.

So this is something I was talking to my brother about. He was telling me I would have to buy large resistors that can handle up to 4kw. Is there a way to split the voltage without installing expensive resistors?

 

[camelCase]

No resistors required. Here is a wiki page that discusses series vs parallel panel wiring.

https://diysolarforum.com/ewr-carta/parallelorseriespanels/

 

[MisterSandals]

Can you post pics of the display on your Growatt? We should figure your system out to identify problem(s) before implementing solutions.

If you can snap a pic of your panels that would help. You will likely need a pic of the specs on the panel underside. Taking pics with a phone a pain but doable.

 

[Hedges]

As far as replacing the panels, I don't have the money to do that. I blew all of my liquid funds on the battery, so I will have to start saving up again.

4000W of PV panels for $1135 (plus shipping.) For example.

Used Canadian Solar 310W Poly 72 Cell Solar Panel - SanTan Solar Store

Check out our Used Canadian Solar 310W Poly 72 Cell Solar Panel for only $88.00! Limited quantity! Get yours today! San Tan Solar one year limited warranty.

store.santansolar.com

Sounds like you found an inverter or less, so if you can return the lower voltage one for refund that's better.

Research functions of inverters and their efficiency and standby loss carefully. You want something that works well for your purpose, and some or better suited to one application than another.

No resistors required. Here is a wiki page that discusses series vs parallel panel wiring.

https://diysolarforum.com/ewr-carta/parallelorseriespanels/

Unless he has those oddball high voltage panels. Some individual panels are several hundred volts.

So this is something I was talking to my brother about. He was telling me I would have to buy large resistors that can handle up to 4kw. Is there a way to split the voltage without installing expensive resistors?

Using resistors to reduce voltage would be an absurd solution. Resistors accomplish this by dissipating a huge amount of power, e.g. might be 50% efficient, dump the rest of the power as heat.

Inverters and charge controllers are switch-mode power supplies, perform a function for DC similar to what transformers do for AC. They are 90% to 99% efficient.

 

[JoshuaC0352]

Can you post pics of the display on your Growatt? We should figure your system out to identify problem(s) before implementing solutions.

If you can snap a pic of your panels that would help. You will likely need a pic of the specs on the panel underside. Taking pics with a phone a pain but doable.

I don't have the Growatt inverter, but here is my current inverter

 

[JoshuaC0352]

Can you post pics of the display on your Growatt? We should figure your system out to identify problem(s) before implementing solutions.

If you can snap a pic of your panels that would help. You will likely need a pic of the specs on the panel underside. Taking pics with a phone a pain but doable.

 

[JoshuaC0352]

Can you post pics of the display on your Growatt? We should figure your system out to identify problem(s) before implementing solutions.

If you can snap a pic of your panels that would help. You will likely need a pic of the specs on the panel underside. Taking pics with a phone a pain but doable.

 

[JoshuaC0352]

No resistors required. Here is a wiki page that discusses series vs parallel panel wiring.

https://diysolarforum.com/ewr-carta/parallelorseriespanels/

OK. So you're saying if I rearrange the panels to be parallel this will reduce the voltage?