Tiago optimizers or not? Please read below

Galego said:

Jinko 410W Tiger Neo N-type 54Cell AB

Click to expand...

You don't need optimisers. It's a bit of shade late in the day at one end of the array. These panels are a half cut and will have good shade tolerance and not hurt the rest of the array's production. An inverter with a good global MPPT algorithm will manage it.

You could put an optimiser or two up there but I somehow doubt you'll recover the cost in extra production. Optimisers don't make sunshine, they are supposed to help reduce the negative impacts of partial shading on the rest of the string. But modern panels and string inverters manage it very well now such that there's not much left squeeze out of the stone.

Galego said:

Now in a serious note. Is there any way to determine that all 10 panels are up and running (and none is acting up or faulty)? And without having to go up the roof!!

Click to expand...

Just monitor production and compare with an expected output for such an array configuration. You could use a service like solcast to provide some estimates:

billt1827 said:

2.2kWh reclaimed out of 8kWh generated.

Click to expand...

Just exactly how is this claimed extra energy calculated?

wattmatters said:

Put in reverse cycle aircon for heating and get rid of the chimney.

Click to expand...

That wasn't a joke. It's a pretty common strategy in Australia as homes transition to all-electric, ditching gas and other forms of combustion heating/cooking.

Roof real estate is valuable and many fireplaces are archaic and often a health hazard, they are certainly poor for drafts. Lots of homes here with these older style fireplaces end up blocking them off anyway. Modern fireplaces of course are much better but many homes do not have such fireplaces. Burning wood in suburban areas is just bad news for the air quality. It's a health hazard.

I have one monster fireplace with a large brick chimney I can't wait to get rid of. Not only will it reduce the shading I get on some panels, it will open up the ability to put at least another 10 PV panels up. I have two of those chimneys, this place has two large open fireplaces.

I have no idea, but I have no reason to doubt that some significant amount of energy is being made available that would not be available without the optimisers.

There are 3 systems here with different orientations and degrees of shading. One system has a little shading in the early morning and shows little recovered energy the others have significant shading during the day and show significant recovered energy.

billt1827 said:

I have no idea, but I have no reason to doubt

Click to expand...

I have reason to doubt. You should too.

The chimney that I removed was 3 ft by 6 ft. Allowing 4 more panels and open sky to the rest.
Well worth it.

Actually I don't.

I've just spent a bit of time looking at the logs from the Tigo cloud. They log current and voltage from each Tigo'd panel, so they can work out the instantaneous power for each panel. The outputs of the panels can be compared, so if you have one panel with a low output and another with a high output you can deduce that, without an optimiser the higher output panel would have its output reduced to that of the low output panel, hence you can make an estimation of the power recovered.

By way of illustration here are some graphs of the outputs of my systems. The first one is the one that shows little benefit from optimisers. It's an array of 6 285W panels, the lower 3 have some shading from trees early in the morning. The top 3 don't have any so they don't have optimisers. You can see there's a bit of variability in output at the beginning and end of the day, but nothing much for most of the day. Hence there's no opportunity to recover energy, which is agrees with the recovered energy graphs. (87Wh recovered from 2.96kWh)



Here's another system. A row of 6 280W panels above a row of 220W panels with shading from a neighbouring property.



You can see a fair amount of variation at the end of the day. (1.82kWh recoverd from 14.6kWh)

And lastly a more complicated system. 4 390W panels on a south facing roof, 2 vertically mounted 220W panels facing east and 2 vertically mounted panels facing south.



Considerable variation from the low output panels but little from the high output panels. (2.99kWh recovered from 7.1kWh).

I doubt that the recovered energy estimates are completely accurate, but they are credible.

Not sure why all the hate towards Tigo — I’m a fan. Even those panels not directly shaded can benefit from installing optimizers. Also, it is incredibly valuable to be able to “see” what each panel and each string is doing in terms of power, voltage, amps, etc. at any moment in time. I learn a lot more from my Tigo app (panel-centric) than my OpticsRE app (inverter-centric).

Galego said:

Thanks for the quick and handy solutions "get rid of the chimney" or "rotate the house"....haha

Now in a serious note. Is there any way to determine that all 10 panels are up and running (and none is acting up or faulty)? And without having to go up the roof!!

Click to expand...

Open Circuit Voltage is a good indicator that all panels are producing.

timselectric said:

Open Circuit Voltage is a good indicator that all panels are producing.

Click to expand...

I tend to disagree. I've had a number of panels show good VOC, but output 25% of they're rated STC.

billt1827 said:

so if you have one panel with a low output and another with a high output you can deduce that, without an optimiser the higher output panel would have its output reduced to that of the low output panel,

Click to expand...

It's a pretty big assumption that the other panels' performance will be degraded by that much if the Tigo was not there. Modern panels are already very good at not impacting the rest of the string.

MJSullivan said:

Not sure why all the hate towards Tigo

Click to expand...

There is no hate towards the product per se. But when claims of performance gains are made, they need solid evidence to back them up.

Lt.Dan said:

I tend to disagree. I've had a number of panels show good VOC, but output 25% of they're rated STC.

Click to expand...

I'm not sure how that would happen. But ok.

timselectric said:

I'm not sure how that would happen. But ok.

Click to expand...

I'm not sure either. Idk how it works or anything, but I warrantied 8 panels to San Tan Solar for this exact reason and they gave me new (to me) ones.

Is there something that directly relates VOC to panel output? I saw it consistently on 8 out of 60ish panels, that it would have a good VOC, then you would apply a load (MPPT to battery) and voltage would drop to 50ish %, and current was abysmal.

wattmatters said:

It's a pretty big assumption that the other panels' performance will be degraded by that much if the Tigo was not there. Modern panels are already very good at not impacting the rest of the string.

Click to expand...

It's a pretty big assumption that my system has modern panels - most of them are 9 years old Some modern panels probably don't need optimisers, in fact I have 8 here that claim to optimise without external help, as I don't have panel level monitoring I have no practical means of checking whether they work or not.. That doesn't mean that Tigo optimisers don't do what they claim.

I get it; you don't like Tigo. That doesn't mean that they don't work.

I agree that they aren't worth it in most situations but don't condemn them out of hand.

billt1827 said:

I get it; you don't like Tigo. That doesn't mean that they don't work.

Click to expand...

What gives you that idea? Nothing wrong with Tigo per se.

Tigo have some specific use cases but the OP's case isn't one of them. I considered them myself but once I'd done my due diligence recognised they were not worth it in our case.

wattmatters said:

What gives you that idea? Nothing wrong with Tigo per se.

Click to expand...

Might be because every post that you've made in this thread is some variation of "don't use Tigo optimisers". When I gave evidence that Tigo optimisers work you poured scorn on the idea.

I should also point out that in my first post I said that optimisers probably weren't worth it in the OPs case.

Lt.Dan said:

Is there something that directly relates VOC to panel output?

Click to expand...

Not necessarily. But the correct VOC confirms that all cells in a panel are connected. (Not bypassed by the diodes) If a single cell was shorted, the VOC difference wouldn't be as noticeable. But would lower the output.

Lt.Dan said:

I'm not sure either. Idk how it works or anything, but I warrantied 8 panels to San Tan Solar for this exact reason and they gave me new (to me) ones.

Click to expand...

All of my panels have come from SanTan Solar, also.
Their customer service is exceptional. Had 3 refunded, out of 100. Great company to deal with.

billt1827 said:

When I gave evidence that Tigo optimisers work you poured scorn on the idea.

Click to expand...

Please do not mistake my request for clarification on the methodology used to claim a performance outcome for "scorn". It's not scorn, it's a healthy process of skepticism.

I was open to learn how such performance measure is arrived at. However it would appear the methodology is rather limited. This does not mean the assessment is wrong, just that the methodology in support of it is weak. This is not scorn, it's just being objective.

Being rigorous in how we assess performance of systems is vital to ensure we understand the validity of information presented.

I'm glad they are working for you, and we are in agreement wrt to the OP's case. There is much more we agree on than any differences.

I have a solar system installed in May this year, and believe I might have faulty Tigo optimizers. Would like to have your view on this.

My installation has two strings with 16 and 12 panels respectively. Both strings are installed with the same roof angle and direction. The strings are connected to separate inputs on a Growatt inverter. Tigo optimizers are installed on the 8 encircled panels, see photo. The panels are of half-cut type with by-pass diodes in 3/6 arrangement.

The small string receives a shadow from the roof next to it, until around 14:00. The photo below illustrates, taken at 13:07.

The current graph shows the typical behaviour of my system. Taken from a sunny day (full sunshine up until around 16:00), the graph compares the current from the two strings. When both strings are in full sun with no shade the currents are as expected equal.

The problem is that I get no current at all from the small string until only half the last row is left in shade, at around 12:50. And at that point I only get 50% of the current. Shadow situation at that point is about as shown on the photo.

I would have expected to get full current at least from the time when 8 panels are in full sunshine. With good optimizers maybe I could get full current already when half the middle row of panels are in sunshine.

(BTW, I have verified that the inverter operates fine with only 6 or 8 panels. I tested to cover 4 and 6 panels with blankets, and in both cases I get full current from the string. I have also seen two days this summer when the system behaves very differently and outputs full current already when the middle row gets full sun. However these two days it turned the current down to 50% at the time where I usually start to get current, resulting in a reduction of the power output.)

What do you think?