Does 'grid first' work on latest gen-3 hybrid firmware?

Hi,
I'm currently running firmware 305 - have deferred upgrade since there are some concerns about 3015 battery firmware. The remote-control on the portal offers a 'general' setting 'export power priority' with options 'load', 'battery', 'grid'. But this appears to have no effect on the behaviour of my system. Just wondering if it behaved on 307. (I obviously should have asked earlier in the day while the sun was still up, so that people could test it.)

What I want is that 'grid' means the inverter will generate AC up to the max (5kW for me), and then send surplus to the battery. This may sound a bit odd, but because I'm on IOG tariff, I currently charge battery overnight, and inhibit solar charging during the day, just exporting everything I can. Today I was rather surprised to see the solar peaking at 5.5kW when the sun came out between clouds. So I'm getting into clipping territory unless I divert something to battery.

Yes, I could manually (or via an automation) adjust the charging rate to try to keep AC maximised, but if grid-first is supposed to implement such a scheme anyway, it makes more sense to use it.

Related question: the inverter was running at around 500W at midday - does that come from the AC part of the budget, or the DC part ?

If you are seeing 500W in my app it's probably more due to inaccuracies in the inverter readings than actual consumption. Logically if the panels are generating 5.5kW and 5.0kW is coming out the inverter then consumption would be 500W, But if the 5.5kW is really only 5.3kW (4% error) then consumption would only be 300W. Remember the the 5.5kW figure is calculated by multiplying the voltage and current of each string then adding the results. Possible inaccuracies all round. If it is really dissipating 500W, I would expect the inverter temperature to be between 70C and 80C at an ambient temperature of 20C.

To answer the original question, on my gen1 hybrid I haven't found a way to make it do that. It would certainly be useful as a means of controlling clipping. Timed discharge doesn't help, I have found that the battery won't charge during a timed discharge period.

The best way I found to deal with clipping last summer is documented here
https://givenergymonitor.wixsite.com/tutorials/clipping

A less-than-helpful reply from givenergy support: despite me saying that it has no effect on my system, they tell me that "those functions are available on your inverter".

Just bumping the thread, in the hope that someone has had a chance to try this, now that the days are getting longer. I did report a bug via feedback, but not convinced GE ever look at these. Perhaps I'm just missing a simple trick, like you have to turn off eco mode to use it ?

Otherwise, I guess I'm going to have to implement some kind of monitoring scheme to tune the charging rate. (I see the predbat people are thinking about it too: https://github.com/springfall2008/batpred/issues/886 )

@geoffreycoan I think you're interested in this ..?

First day my anti-clipping script ran unattended (since I was out all day), and quite please with the result:

The grid export is a proxy for AC generation, which is slightly higher (also includes house load). Script tries to keep it in the range 4500W to 4800W, and adjusts the max battery charge rate as reqired if it goes above that.

Other than a bit of an over-reaction between 14:30 and 15:00 it seems to have done a pretty good job. (And maybe what it did then was entirely correct, and just looks wrong here because of the 5-min sampling.)

Maybe next step is to allow it to also discharge battery if it's above, say, 50%, and AC generation is sufficiently low. (Couple of times, I've started an export to grid in the early evening, only to have the sun make a late reappearance and mess things up.)

An update, for anyone interested... I've add a snapshot of monitor.py to https://github.com/divenal/givenergy-scripts (sorry, the README's a bit out of date).

Export is a proxy for ac generation, which is slightly higher (since it has to include the small house load).

A snapshot of the logging, for anyone interested in details:

                      -------solar-------   --------gen-------    --export--   ---------battery----------   -temp- -time-
2024-06-15 12:35:22:  5287 4553.1 4553.1   4604 4018.1 4018.1   4386 3819.9     -27  -27.2   1  50 1  32   36.3   74169 30
2024-06-15 12:35:53:  5285 5102.0 5102.0   4976 4736.5 4736.5   4863 4602.2     -28  -27.8   1  50 1  32   36.4   74199 15
2024-06-15 12:36:08:  5279 5234.8 5234.8   4974 4914.6 4914.6   4863 4797.8     -27  -27.2   1  50 1  32   36.2   74214 10
2024-06-15 12:36:18:  5744 5616.7 5616.7   4973 4883.4 4883.4   4865 4848.2    -476 -363.8   3  50 0  32   36.5   10 10
2024-06-15 12:36:29:  6013 5913.9 5913.9   4969 4872.6 4872.6   4862 4858.6    -763 -663.2   6  50 0  32   35.8   10 10
2024-06-15 12:36:39:  6137 6081.2 6081.2   4873 4797.9 4797.9   4758 4783.1   -1054 -956.3   9  50 0  32   36.2   10 15
2024-06-15 12:36:55:  6292 6239.3 6239.3   4906 4879.0 4879.0   4799 4795.0   -1053 -1028.8   9  50 0  32   36.3   25 10
2024-06-15 12:37:05:  6291 6278.1 6278.1   4589 4586.5 4586.5   4480 4558.8   -1343 -1264.5  12  50 0  32   36.2   10 30
2024-06-15 12:37:36:  6192 6213.5 6274.8   4524 4539.6 4584.2   4423 4456.9   -1343 -1323.4  12  50 0  32   36.6   40 30
2024-06-15 12:38:07:  6192 6197.4 6271.0   4524 4527.9 4581.3   4423 4431.5   -1343 -1338.1  12  50 0  32   36.6   70 30
2024-06-15 12:38:37:  6353 6314.1 6314.1   4667 4632.2 4632.2   4555 4524.1   -1348 -1345.5  12  50 0  32   37.0   100 30
2024-06-15 12:39:08:  6470 6431.0 6431.0   4919 4847.3 4847.3   4797 4728.8   -1345 -1345.1  12  50 0  32   37.4   130 10
2024-06-15 12:39:18:  6679 6617.0 6617.0   4393 4431.6 4541.5   4382 4468.7   -1640 -1566.3  15  50 0  32   37.5   10 30
2024-06-15 12:39:48:  6369 6431.0 6607.7   4394 4403.4 4534.6   4272 4321.2   -1640 -1621.6  15  50 0  33   37.7   40 30
2024-06-15 12:40:19:  5127 5453.0 6550.0   4386 4390.3 4527.4   4282 4291.8   -1640 -1635.4  15  50 0  33   38.0   70 30
2024-06-15 12:40:49:  2885 3527.0 6398.8    330 1345.1 4368.3    325 1316.7   -1642 -1640.3  15  50 0  33   38.4   100 30
2024-06-15 12:41:20:  1754 2197.3 6188.7   3045 2620.0 4280.9   2711 2362.4   -1544 -1568.1  14  50 0  33   38.5   30 30
2024-06-15 12:41:50:  6517 5437.1 6151.2   4569 4081.8 4270.9   4458 3934.1   -1545 -1550.8  14  50 0  33   38.9   60 30
2024-06-15 12:42:21:  6400 6159.3 6159.3   4528 4416.4 4416.4   4419 4297.8   -1543 -1544.9  14  50 0  33   39.0   90 30
2024-06-15 12:42:51:  6485 6403.6 6403.6   4602 4555.6 4555.6   4493 4444.2   -1545 -1545.0  14  50 0  33   39.3   120 30
2024-06-15 12:43:21:  2768 3676.9 6267.2    145 1247.7 4390.2     11 1119.3   -1266 -1335.7  14  50 0  33   39.6   150 30
2024-06-15 12:43:52:  6335 5670.5 6237.4   3705 3090.7 4325.2   4432 3603.8   -1445 -1417.7  13  50 0  34   39.6   30 30
2024-06-15 12:44:22:  6201 6068.4 6228.9   4412 4081.7 4313.1   4302 4127.5   -1448 -1440.4  13  50 0  34   39.7   60 30
2024-06-15 12:44:53:  6152 6131.1 6224.1   4482 4381.9 4381.9   4371 4310.1   -1350 -1372.6  12  50 0  34   40.1   30 30

The 'solar' and 'gen' triplets are the instantaneous reading, a fast moving average, and then a slow sawtooth sort of filter (rises instantly, but decays slowly). Then 'export' is the reading and the moving average.

battery is power in/out (-28 is the typical paused value) and moving average ; charge and discharge power (as %ge of capacity, so for my 9.5kWh battery, each step is about 95W, though it's not linear and adds around 150W) ; paused flag (1 = charging paused, 0 means unpaused); SoC %

Then the last three columns are inverter temp, the seconds since the last change, and the seconds it intends sleeping for until the next update. (Typically 30 seconds when solar exceeds 5kW, 5 minutes at night, but it sets it to 10 seconds if something interesting is happening - typically after it suspects clipping, since it doesn't know how much it needs to increase battery charging by.)

So at the start of the log, solar and generation is well under 5kW, so battery charging is paused.
At 12:36:08, generation exceeded 4900W, so it unpaused the battery and set charge power to 3 (about 450W). Set time delay to 10 seconds since it's likely 450W wasn't enough. Sure enough, it had to increase it up to 12 before it got the generation down 4900W.

It sits there for a little, and generation creeps up, so it once again increases charging power to 15.

Then the generation starts to drop around 12:40, so it slowly reduces the charging power, trying to keep generation between 4500W and 4800W or so.

And that's all there is to it, really...

I have a Gen3, and turning ECO off does this? everything up to 5kW goes to the grid and home and the battery is idle.
anything above 5kW gets pushed to the battery.

wrighar oh, it's as simple as that? I had been wondering, since I'd seen something along those lines mentioned on an issue related to clipping on predbat. (That also mentioned using timed discharge - not sure how that fits into things.)
https://github.com/springfall2008/batpred/issues/1206#issuecomment-2168642857

But I'm pretty sure I tried that, to see if 'grid first' only worked if eco was also turned off. But was probably on firmware 305 - I haven't tried it again since updating to 307. I'll give it a try later since it should be a good solar day.

It's a pity that that turning eco off will also prevent discharge when consumption requires it. (Such as 13:15 on the image above.) But the script becomes much simpler if it's just about turning eco on/off rather than having to adjust charging power.

• I see from another thread that you're on firmware 309.

Good news! Turning off eco mode seems to be all that's needed on firmware 307 too. (Though I'm still not sure that 'grid first' has any effect.)

Also, I can run a timed-export concurrently, and it will automatically switch the battery between charging (when there is excess solar) and discharging, keeping AC generation maxed out. So that's interesting...

wrighar

💡 Whoah. I totally missed that idea. Problem solved. Thanks for that - Seems almost too easy 😂
Going to have a play with that when I next have the time. It’s so easy to overlook the obvious in retrospect ! Of course it’s only obvious now you’ve mentioned it 😂😂

Last few days I’ve been discharging my batteries at 7am, full pelt (4kW) down to about 70% and then wondering why at 09:30, (from my 5.88kW east array) I’m only getting 5kW out of the inverter (panels obviously were being clipped) when I was expecting 5.88kW. Also I hadn’t turned the max charge rate down from 3.4kW to 2.5kW so that might explain things. Simply turning off eco is amazing. Never thought of that. Much more elegant solution.

I thought two of my panels had gone down on that array to be honest. I was really scratching my head, as I’m sure I’d seen the full output last year. But this year I had only very occasionally seen more than 5kW in full sunlight but now I realise whats going on and why I briefly saw above 5kW generation; it was probably when the batteries were getting full and the charge rate ramped down below 2.5kW. Also I was seeing the panel output increase when the car was charging. Just couldn’t work it out, with clouds passing over, rain, full sun etc. Now the penny has dropped.

I thought doing what I did this morning, then (of a potential max 5.88kW) 3.4kW would go to the batteries directly from the DC panels, and 2.5kW to export. But I was only seeing a max of 5kW from the panel generation. I guess the extra 0.9kW was being clipped because I still had the max charge rate instead of reducing it to 2.5kW, so 0.9kW was being nicked from the A/C side of things to charge the batteries. Then when the battery charging ramped down, the panel output was going up !

Thanks for your input. Much appreciated. 👏

DD

That’s excellent news.

DD

I think the timed discharge bit may be to use the battery to house when the solar generation rate drops below home usage rate (a few minutes of cloud cover etc) so you don;t draw from the grid for those moment.

Turning ECO off stops solar charging (below g98/g99 limit), but also discharge.

Yes, I'm on 309, but was on 305 or 307 and did this too.

Another trick (as opposed to the time discharge one) if you don't mind possibly drawing from grid for a few very dull moments is to set timed export and a reserve limit of 90-95%, so whenever it gets dull enough to drop below g98/g99 limit and the battery is over the reserve, it will export back up to that limit, so you hopefully always retain enough space for clipping's

Another day sipping from the clipping part of the curve:
ECO off
Currently set to export between 12:00 and 14:00 down to reserve of 93%