Solar panels for 5kv inverter

[christyvido]

Hi Guys,

Please can you assist me - I'm looking to get a 5kv Sunsynk inverter, a 5.5kw Hubble battery, and solar panels. My monthly usage is 400-500 kW units.

For the solar panels, i have contacted two installers and each recommended different solar panels.

The one installer recommended 8 x 455 solar panels (one single string) and the other recommended 8 x 540w solar panels (2 strings of 4 each).

The 540w panels do produce more power and will hopefully not need to buy more panels in the future, but I have concerns that these might not be the optimal panels for the invertor. However, with the 455w, I will have an extra string to fill up in the future.

Also if a add another 5.5kw battery in the future - would I need to get additional panels depending on the panel I choose?

Not sure which solution would be the best optimal solution? would really appreciate your views and recommendations.

thanks

[SunEagle]

I would choose the panels that can be duplicated in the future. You really don't want to mix and match panels when you expand a system.

You also didn't mention if this system is grid tied. I don't recognize that Sunsynk inverter but if you are going with a battery then my guess it is either a hybrid inverter or an off grid type.

[Ampster]

I am not sure how you define "optimal panels for the inverter“? Your DC to AC ratio is below 1.25 to 1 so you have plenty of room for expansion in both cases. If the system prices and quality of the panels are similar, I would go with the larger system

[sdold]

Feel free to keep the thread going, but the original poster was here to post ads and won't be back. They simply copied/pasted an old post from another forum here to appear to be a legitimate user, and also copied/pasted an Amazon review into another thread and added an ad link.

[Ampster]

So the OP would not care if we hijacked the thread to talk about clipping, high DC to AC ratios or how to game the current TOU rate structure in California. LOL

[sdold]

So the OP would not care if we hijacked the thread to talk about clipping, high DC to AC ratios or how to game the current TOU rate structure in California. LOL

Heh...probably not, so have at it. I have to admit it was a pretty creative tactic.

[foggysail]

Guys! I have a basic question pertaining to mixing panels. Between panels and distribution, either 240AC or whatever DC is either an inverter or an optimizer. Why would it matter if panels are mixed other than physical size matching? I do not see why it matters

Thx

[Ampster]

It does not matter if using micros. One just has to match the specs of the panel to the micro specs so you do not overload the micro. All the systems I have done have used the same panels so I have no experience with the impact of mismatch on the DC side into a String Inverter. There are lots of others better informed on that issue that can give you an explanation.

[foggysail]

It does not matter if using micros. One just has to match the specs of the panel to the micro specs so you do not overload the micro. All the systems I have done have used the same panels so I have no experience with the impact of mismatch on the DC side into a String Inverter. There are lots of others better informed on that issue that can give you an explanation.

Thanks for sharing your thoughts. I cannot see any reason why mixed panels should not be used other than appearance and maybe physical size differences

[Ampster]

Thanks for sharing your thoughts. I cannot see any reason why mixed panels should not be used other than appearance and maybe physical size differences

Since others have not responded, I will try to conceptualize the issue which I understand. It may depend on whether they are in parallel or series but the voltage and/or current can be affected in a sub optimal way by the other mismatched panels in that string. Further inquiry is advised.

[sdold]

...One just has to match the specs of the panel to the micro specs so you do not overload the micro..

What do you mean "overload the micros"? It's common for the panel (STC) wattage spec to moderately exceed that of the microinverter. For example, the Enphase M215 is rated at 215W continuous, but the spec sheet suggests common panel sizes of 190-270W. My system used them with 250W panels and it was a perfect match in Ca Sacramento Valley conditions where I rarely saw more than 80% of STC power produced. Anything over the Microinverter's 225W peak rating saturated ("clipped") the inverters and no more was produced. In non-microinverter systems, it's typically recommended that panels wired in series are within 5% of the others' current, and within 5% of the voltage when in parallel.

[Ampster]

What do you mean "overload the micro"? It's common for the panel STC wattage to exceed that of the microinverter. ...

I should have been more clear. I meant exceed the voltage Specs. Panels of different cell configurations (60, 72 and 96 cells) have different voltages and the components inside the micros may have voltage limit. Yes, my micros typically have DC to AC ratios higher than 1 to 1.

[sdold]

I should have been more clear. I meant exceed the voltage Specs. Panels of different cell configurations (60, 72 and 96 cells) have different voltages and the components inside the micros may have voltage limit. Yes, my micros typically have DC to AC ratios higher than 1 to 1.

True, the Voc of 72 cell panels is uncomfortably close to the max input voltage of the M215. Thanks for the clarification.

[foggysail]

This is getting overly complicated. I have not looked into rapid shutoffs, optimizers and string inverters so my comments here are only for AC systems using micros. I see no electrical reason why panels with different Vmp, different wattages, 62 or 74 cells cannot be mixed with each panel equipped with a dedicated micro. EAch micro is phase locked to the grid so even mixed micros should be fine as long as they are operated in spec.

[Ampster]

This is getting overly complicated. I have not looked into rapid shutoffs, optimizers and string inverters so my comments here are only for AC systems using micros. I see no electrical reason why panels with different Vmp, different wattages, 62 or 74 cells cannot be mixed with each panel equipped with a dedicated micro. EAch micro is phase locked to the grid so even mixed micros should be fine as long as they are operated in spec.

You can can have a mix of panels on your trunk cable. Just make sure the voltage of the panels you use does not exceed the voltage of the micros. There are a lot more choices with IQ7 micros because there are different models with different voltage specs to accommodate more panel sizes. RSD with micros is as simple as shutting down the AC which gives you panel level shutdown.