a few Fronius Primo Questions

[petect]

Hi all
I have a couple of questions about the Fronius Primo that I can't find answers for despite reading everything I can find about it. Hopefully someone who knows this inverter can help me out. They are:
1) Can the Primo be set up to import power from the grid (typical grid tied function) but NOT export to the grid? That is, allow power in, but no power out. I've read that it can be can be set up to limit export, including 0 export, but can't figure out if it can be setup to allow import when in the 0 export mode.

2) Would I have to balance the pv outputs between the 2 Primo mppt inputs? I can connect my approx. 3K of modules into one of the Primo's inputs, and stay well within the inverter's voltage and current limits. Doing so would save me some $$ on copper, etc.

[ButchDeal]

Hi all
I have a couple of questions about the Fronius Primo that I can't find answers for despite reading everything I can find about it. Hopefully someone who knows this inverter can help me out. They are:
1) Can the Primo be set up to import power from the grid (typical grid tied function) but NOT export to the grid? That is, allow power in, but no power out. I've read that it can be can be set up to limit export, including 0 export, but can't figure out if it can be setup to allow import when in the 0 export mode.

2) Would I have to balance the pv outputs between the 2 Primo mppt inputs? I can connect my approx. 3K of modules into one of the Primo's inputs, and stay well within the inverter's voltage and current limits. Doing so would save me some $$ on copper, etc.

1) Grid tie batteryless inverters like this do not control the input of power. that just comes to your loads. it would just cut power so that it never exports.

2) no the inputs do not need to be balanced.

All that said I would look at SolarEdge. It likely is cheaper if you have to do Rapid shutdown than adding that to the primo.
The SolarEdge is more reliable than Fronius and more efficient. and can handle the same zero export.

Also Why are you looking at zero export??

[DanS26]

.........The SolarEdge is more reliable than Fronius and more efficient.........

If you have support for this statement......would you please share it.

[ButchDeal]

If you have support for this statement......would you please share it.

which the reliable or the efficient. The efficient is easy to see on the HDWave documents.
As for reliable. We have installed some Fronius inverters including the primo and some SolarEdge.
The failure rate for Fronius inverters was almost 50% in the first year. One we replaced twice before the year was out.
The failure rate on the SolarEdge is much much lower.

[J.P.M.]

which the reliable or the efficient. The efficient is easy to see on the HDWave documents.
As for reliable. We have installed some Fronius inverters including the primo and some SolarEdge.
The failure rate for Fronius inverters was almost 50% in the first year. One we replaced twice before the year was out.
The failure rate on the SolarEdge is much much lower.

Any verifiable and independent numbers for that failure rate ? Any qualifications of type/mode of failure ?

From your statement, on the face of it, it looks like if someone installs a Fronius inverter, it might have a 50 % chance of a 1st year failure.

Maybe/likely, I'm uninformed/more ignorant than I thought, but if a product has a common 50 % 1st yr. failure rate, I figure it would be known, or at least I might hear about it. If not common, I'd wonder why your Fronius installs fail at a 50 % rate and others (?) don't.

Any communication w/Fronius about what seems to be their high failue rate(s) ?

[ButchDeal]

Any verifiable and independent numbers for that failure rate ? Any qualifications of type/mode of failure ?

From your statement, on the face of it, it looks like if someone installs a Fronius inverter, it might have a 50 % chance of a 1st year failure.

Maybe/likely, I'm uninformed/more ignorant than I thought, but if a product has a common 50 % 1st yr. failure rate, I figure it would be known, or at least I might hear about it. If not common, I'd wonder why your Fronius installs fail at a 50 % rate and others (?) don't.

Any communication w/Fronius about what seems to be their high failue rate(s) ?

We had better results with the primo and started using them, but right away the solaredge installs were showing up with less problems from all the others.
We kept the primos as a lower cost option for a bit till rapid shutdown started being an issue and then just with SolarEdge as the base line system unless customers specifically wanted something else.

As for the high failure rates they said it was a bad batch though we are talking about installed spread out over a years time and different models. The last Fronius we installed was a while ago and we do monitor it. actually a dual inverter system, One of them was replaced twice fairly quickly.

[petect]

Hi Butch
Here

[DanS26]

Thanks Butch....just wanted to know where that statement was coming from.....your business experience and SolarEdge promotional materials.

I just thought you had available some industry analysis that could help me in my next inverter purchase.

[ButchDeal]

Thanks Butch....just wanted to know where that statement was coming from.....your business experience and SolarEdge promotional materials.

I just thought you had available some industry analysis that could help me in my next inverter purchase.

just the specs on the equipment, our experiences,
and cost differences once rapid shutdown is in play in the installation area.

[ButchDeal]

Hi Butch
Here

yeah the forum is getting a lot of truncated posts of late.

[petect]

Hi Butch
Having trouble - so short post. It's my understanding that I use pv to reduce grid use I need to notify the electric co. as long as I don't export into the grid. I want to set up AC coupling with import but NO export to avoid needing a contract with electric co. Hopefully longer post later

[ButchDeal]

Hi Butch
Having trouble - so short post. It's my understanding that I use pv to reduce grid use I need to notify the electric co. as long as I don't export into the grid. I want to set up AC coupling with import but NO export to avoid needing a contract with electric co. Hopefully longer post later

well there are a few miss conceptions there.

First on the technical, the no export and AC coupling do not play well together. You would get a similar result but the bimodal inverter would do all that.
The fronius would have to NOT be in zero export mode to AC couple and the bimodal inverter would handle the zero export by pulling the power to charge batteries, or shut down the Fronius.
It will do it poorly though and more expensivly than a DC couples system which would be able to do zero export much better.

That all said in most locations you are still going to need an interconnect agreement even with grid zero and you will need permit and inspections.
grid zero is going to be much less efficient with electricity (high loss ) as well as hard on the batteries (they will need to be replaced more often)
than if you get and use net metering.

What is the reason for wanting to do zero export? do you not have net metering in your region?

[petect]

Hi Butch Hopefully this post will workl
I guess I'm confusing things by trying to do 2 things that aren't connected.In order of importance, they are.
1) The power goes out here for 1/2 day or more at least a few times a year, The usual scenario is a tropical or winter storm comes thru, power goes out, while we have blue sunny weather. The power has been out for over 10 days twice in the last several years. Grid tied pv won't work until the grid is back up.
I could get by with a few hours of sun on most days, and a generator, as my loads are small. It won't take much to run my refrigerator, freezer long enough to get them cold, and top off a small battery bank. I would use a transfer switch to disconnect from the grid when using the generator, and want to be able to use my pv also. Outback says it's inverters can operate in a "minigrid mode", and I'd like to be able to operate in a similar manner.

2) Of less importance, I'm a former employee of an electric company and have seen how much influence power companies can have on lawmakers to pass / change legislation in the company's favor. Look at what has been happening in Nevada. That's why I'd like to avoid a net metering agreement with the power company.
And yes, I will have anything I do inspected, and use a licensed electrician where necessary.
Thanks
Pete

[ButchDeal]

Hi Butch Hopefully this post will workl
I guess I'm confusing things by trying to do 2 things that aren't connected.In order of importance, they are.
1) The power goes out here for 1/2 day or more at least a few times a year, The usual scenario is a tropical or winter storm comes thru, power goes out, while we have blue sunny weather. The power has been out for over 10 days twice in the last several years. Grid tied pv won't work until the grid is back up.
I could get by with a few hours of sun on most days, and a generator, as my loads are small. It won't take much to run my refrigerator, freezer long enough to get them cold, and top off a small battery bank. I would use a transfer switch to disconnect from the grid when using the generator, and want to be able to use my pv also. Outback says it's inverters can operate in a "minigrid mode", and I'd like to be able to operate in a similar manner.

2) Of less importance, I'm a former employee of an electric company and have seen how much influence power companies can have on lawmakers to pass / change legislation in the company's favor. Look at what has been happening in Nevada. That's why I'd like to avoid a net metering agreement with the power company.
And yes, I will have anything I do inspected, and use a licensed electrician where necessary.
Thanks
Pete

A dc coupled system like those from outback can give you backup capabilities with out without zero feed in.
i would highly suggest that you work in a dc coupled solution.

2) you will have to investigate if you need an interconnect agreement for zero feed in connection or not. You can feed in with a net metering agreement and still have backup. This is what I do. That way the batteries are cycled very little. Earlier this week the power when tout three times (or more) the only what we could tell is that the stove clock was flashing when.
You can always change to a zero feed in if net metering is changed on you. It is just a configuration Change though you should use different type of batteries for zero feed in.

[petect]

Hi Butch
Thanks again for your help. Yes I have some homework to do.
Concerning Fronius vs. SolarEdge. I'm not an electronics guy, but I do know that electrolytic caps. are often fail over time. A picture of the inside of a Primo showed a bunch of electrolytics including some pretty big ones. In the SolarEdge brochure, they make a point of using thin film caps, instead of electrolytiscs. So while that isn't the whole story, it's a plus from where I stand.
Pete