Finally, the start of my 25kw Ground Mount grid-tie system

[live4soccer7]

Yeah, it was pretty crazy. We could not have been any closer to the fire without burning ourselves. I'll have the reported numbers for august, I just haven't had the time or energy. I'm a bit drained physically and emotionally.

Fingers crossed you guys do well.

 

[wattmatters]

There is no rush, let alone a need to compile and post data. Focus on recovery for yourself and your family.

 

[live4soccer7]

We are ok now. It's more or less just processing everything. It doesn't quite feel real even though you see it with your eyes. We look across the lake where the vast majority of the homes were lost and it is just brick chimnies and foundations. It looks like a warzone.

 

[wattmatters]

We are ok now. It's more or less just processing everything. It doesn't quite feel real even though you see it with your eyes. We look across the lake where the vast majority of the homes were lost and it is just brick chimnies and foundations. It looks like a warzone.

That's what it was like in the area where my mum used to live after the devastating 2003 Canberra fires. Her suburb was badly hit with hundreds of homes lost and I recall driving around the streets being shocked and amazed. Places razed to the ground while a lone house among them was untouched.

This was just up the road from where she lived:

Awful stuff.

 

[live4soccer7]

It is crazy and awful. Thank you for sharing.

 

[live4soccer7]

I'll get some numbers up soon for anyone curious, but 2023 yielded 61.98MWh with the projected range of 57-63 from pvwatts at the time a made that print out.

I got the highest voltage at the inverters I have seen to date today. It is -10F outside right now. They hit 800vDC give or take a volt or two. Max voltage is 1000vDC. Total lifetime production between each inverter is within .1MWh. I think that's pretty good, but I'm no professional.

 

[wattmatters]

Good to hear you are back online. Hope the fire recovery is going OK.

We had a total generation of 17.342 MWh.

I posted my system summary here:

2023 Home Energy Summary

How did everyone's home energy systems perform in 2023? This is our system's summary for the year (Northern NSW, Australia): Legend top chart: Teal = battery discharge Pink = battery charge Orange = self-consumed solar PV Blue = Imports from grid Purple = Exports to grid Lower chart shows...

diysolarforum.com

 

[live4soccer7]

@wattmatters Great summary! Way better than mine. ha.

We are doing well. Just a bunch of logging going on in the area and demo work. A home here and there being rebuilt already. I've been occupied with all of that and then I've also been working largely on a heat reclamation system I built for "servers" I have that run in immersion fluid. I just activated that system a few days ago. Still a LONG ways from being done, but at least working now.

 

[live4soccer7]

Just happened to look at my solar prod in grafana today and noticed inverter 2 wasn't producing. It received an error 427, which has basically no description in the troubleshooting information. Is all I can find is hardware fault/error. It did this on startup this morning so it was never producing. It was registering the pv voltage. I killed grid power to the system and all of the inverters restarted. It started producing again, but a bit concerning it may be the start of a larger issue w the inverter. hmm...

 

[wattmatters]

Unusual error code. Hopefully just an anomaly caused by some unusual trigger.

 

[live4soccer7]

Unusual error code. Hopefully just an anomaly caused by some unusual trigger.

At this point, that is my thought. Fingers crossed, otherwise expensive and a PIA. I did register them, but can't recall what the supposed warranty is. Warranties are always a pia and pretty much are granted the way you would expect.

Edit: I think a 2yr warranty is the standard warranty included on them. That gives me until Oct, assuming it starts when they are installed/registered. If from the purchase date then I just hit 2yrs a little over 2 weeks ago.

 

[wattmatters]

Edit: I think a 2yr warranty is the standard warranty included on them.

Wow that's not great. It's 10 years standard here. First five years covers all costs (replacement, transport, installation), second five years the inverter cost only is covered. An additional 10 years coverage can be purchased, it's ~US$57/year.

 

[live4soccer7]

Wow that's not great. It's 10 years standard here. First five years covers all costs (replacement, transport, installation), second five years the inverter cost only is covered. An additional 10 years coverage can be purchased, it's ~US$57/year.

I was wrong. I just logged in and it shows warranty to OCT 2032, so 10yrs from install/registration. I'll probably know of it becomes an issue by then. Ha.

 

[live4soccer7]

Today it worked as expected, so hopefully just a weird series of things that tripped that error.

 

[live4soccer7]

Another day without issues.

I'm loving the data that I've logged within HA. I'm thinking of building an addition on our detached garage that will have a roofline at about 20ft high. I was able to use projections from suncalc.org and then use data from last year to see at what point it would affect the solar production. It hits the array at the very end of the day when each inverter is producing about 1kw of power on a perfectly clear day. The overall affect on production would be nearly negligible across that time of year since it looses all light shortly after that.

 

[live4soccer7]

How would I go about calculating the peak productions on a multi-oriented system? I currently have 45kw facing directly south, however I am looking at adding on to a garage that will have a fairly large E-W facing roof. I'm still in the design and thought phase of the garage, but I want to take into consideration that I may install panels on both E-W sides, but it would be added on to the existing system. Many things to consider and at this time it is just a thought.

I am considering doing a standing seam roof as opposed to asphalt shingles. I know I've seen some roof racking that literally just clamps onto the standing seems, eliminating the need for a lot of hardware and also eliminating the need to put holes in the roof.

Thoughts on this?

BTW, the fronius inverter has yet to give me any more guff.

 

[Ampster]

PVWatts gives good estimates..You will have to make multiple passes, one for each different tilt and azimuth and add the values.
Depending on wind loading, you may need to increase the number of fasteners on your standing seam roof where the panels will be. I don't know the calculation but it is only necessary in high wind areas and your roofer may know

 

[Hedges]

For multiple orientations, each evaluated separately on an insolation calculator would give kWh/day for various seasons.

If fed to multiple inverters, after applying efficiency losses those numbers should be valid. Peak output is expected to be less than sum of peaks, but during times of reflected light from clouds maybe both inverters put out their maximum (for AC current and breaker size calculations.) By trig you could estimate likely peak power from area presented to sun.

If fed to multiple MPPT of a single inverter, total power limited to inverter output, each array performs according to insolation calculator.

If different orientation strings are paralleled onto a single MPPT (strings should be same voltage), I've read a test showed 2% reduced kWh compared to separate MPPT because not exactly at Vmp. More hours of production, so better utilization of hardware from my point of view.

Efficiency of MPPT and inverter will vary with PV voltage and watts being processed. The difference between 98% and 99% isn't very significant in terms of production, but it is 2x difference in power dissipated in inverter and temperature rise, which shortens life.

 

[wattmatters]

I want to take into consideration that I may install panels on both E-W sides, but it would be added on to the existing system

Using existing inverters?

That's a bit tricky.

I think really for system config it's just better to use the Fronius configuration tool and not be concerned with orientation so much, just assume they can all peak at once (which at noon on a Summer's day they will be close enough to that). Gives safety headroom.

Strings in parallel will need to be the same voltage spec, preferably using the exact same PV panel model/rating and same number of panels.

Solar.creator

creator.fronius.com

My system has two MPPTs, one with 2 x NE strings in parallel, the other is 1 x NE + 1 x NW in parallel. Works well. Here's the MPPT outputs for each on a sunny Summer day:



Can see the 2 x NE string clips as it's hitting the current limit on that MPPT, while the other MPPT has a higher current limit and it does not get that high. Plus there may be some volt-watt power limitation going on due to high grid voltages.

Charting the MPPT DC current makes this more obvious:



I can envisage east and west arrays will have curve peaks separated by about 90 minutes or so I guess, maybe two hours apart. Haven't looked at it in detail.

 

[live4soccer7]

They would get their own inverters. My fronius are already maxed. It would be more or less a limitation on what my service/infrastructure up to my meter could handle. It would also be nice to even out production through the day a little better. In my current scenario it doesn't matter much, but who knows how it will evolve over time. Panels are so cheap now and with the right roofing, installation and "racking" would be cheap enough.

It's just something I've been mulling over. One can always use more power