Dealing with excess solar:

[richbee]

I have this problem with my extra Hoymiles PV - where the voltage goes above 253 during exporting and it trips out.
I have reduced the charge current for the batteries to try and spread out the charging time, but at the moment, the battery doesn't discharge that much overnight, so can only help a little bit.
I've also capped the export at 3.4kW in the Sunsynk system with CT coil, rather than the maximum setting of 3.9kW, in the hope of reducing the peak voltage during sunny days.
It still tripped out most days over the past couple of weeks - but in most cases not for too long.
It's frustrating

[sharpener]

I have this problem with my extra Hoymiles PV - where the voltage goes above 253 during exporting and it trips out.
...
It still tripped out most days over the past couple of weeks - but in most cases not for too long.
It's frustrating

I too am quite close to the limit. Fortunately I reused an old 6 sq mm shower cable to my loft so it is quite low resistance. Is there anything you can do to reduce any voltage drops between the inverter and the incoming connection?

If you are within the export current limit agreed with your DNO surely it is their problem to ensure that the voltage at their supply head does not exceed the 230 + 10% statutory limit? Have you spoken to them?

[Mart]

Also, for a DC side battery, especially with the massive Wp overcapacity that Solaredge inverters can handle (up to 200% of rating), then it may be wise to prevent the battery filling before peak generation, so that the inverter output + battery diversion, doesn't fall short of generation.

PS - My SE inverters shutdown temporarily if grid voltage reaches 253V. Hasn't happened for many years.

Not sure I quite understand.

My DC side MPPT is what gets controlled to limit production, in order to preserve max generation hence income from the older FIT setup. Also the Victron can turn down the MPPT at will, but can only shut off the old Steca inverters by frequency control and that only in off-grid (power cut) mode.

Hi, and sorry I was digressing as usual, a major fault of mine. I just meant that if you (people in general, not you specifically) have a SE system, with a DC side battery, and upto 2x the Wp of the inverter rating, then you don't want the battery to be full, when PV gen is peaking, as generation will then be limited to the inverter rating. If there is room in the batt, then generation can exceed the inverter AC output, by a combination of DC battery charging, and AC output.

Ignore me, it seemed important at the time, now I'm less than sure.

[Lincs Robert]

Ive been using it “manually” today and it seems to be doing the job. Just to comment that the inputs seem to operate when they have the required +5 volt signals for a duration of about 10 seconds. This isn't documented anywhere, at least that I can find anyway, so I’m still not sure whether the intention is for the inputs to be high as needed - but the inverter stays at that state until it’s either powered off or midnight. Anyway, 10 seconds does the trick - I’ll experiment further when my wifi switcher arrives. I suspect it will work at less than 10s, but it certainly isn’t a momentary only trigger.

The GPIO pins for this have GND, +5, L1, L2, L3 & L4. I’ll be switching the +5 via external relay contacts, so only five wires required.

[resybaby]

There is a related issue whereby with a lot of generation it can be better to charge the battery at half the rate for twice as long so you are not trying to export above your limit as soon as the battery is full.

Anyone already doing this, and how?

I have done this with my Sunsynk system, turned down the charge rate - some days as low as 10a. Im here all day mind to monitor battery filling.
Once the battery is full then it ramps down as i have zero export set (DNO restricting me to just 3.6kw that the FIT outputs)

The FIT system is also a Sunnyboy and uncontrolled and i want that working at maximum for f8nancial reasons.

Seems a huge waste of power potential to me, but as low leccy users, lots of batteries and panels im over specced for the winter. Goal being no leccy bill all year bar standing charges.

Have had discussions with neighbour about throwing a suitable extension lead over the wall to his to power his immersion - he runs his house on LPG gas so would save him a fortune with me providing power to heat his cylinder.

[ecogeorge]

Seems a huge waste of power potential to me, but as low leccy users, lots of batteries and panels im over specced for the winter. Goal being no leccy bill all year bar standing charges.

Have had discussions with neighbour about throwing a suitable extension lead over the wall to his to power his immersion - he runs his house on LPG gas so would save him a fortune with me providing power to heat his cylinder.
[/quote]

Love that idea ...........
How about a small above ground swiming pool to absorb excess electric? or heated greenhouse ??

[AE-NMidlands]

Seems a huge waste of power potential to me, but as low leccy users, lots of batteries and panels im over specced for the winter. Goal being no leccy bill all year bar standing charges.

Have had discussions with neighbour about throwing a suitable extension lead over the wall to his to power his immersion - he runs his house on LPG gas so would save him a fortune with me providing power to heat his cylinder.

Love that idea ...........
How about a small above ground swiming pool to absorb excess electric? or heated greenhouse ??

and when those are boiling?
Most years we have to put a thin sheet over our greenhouse to protect the (mostly) tomato plants in it. I usually spray them with Bordeaux Mixture so the overspray gives us a level of heat-blocking film on the side windows too.
Our solar thermal tubes have a heat dump mechanism which uses the boiler primary circuit, but I still have a thermostatic mixing valve switched in on the bathroom basin hot tap for when the grandchildren visit...

I am suspecting that my pv export is getting limited by the inverter when the grid voltage goes up near 250V...

[resybaby]

I do have a Koi pond so have mused with bunging s9mething like a 1kw heater in there.

As for neighbours cylinder heating up, it wont make any difference as the Sunsynk will just ramp down to zero again once alls hot, but the neighbour will have a nice hot cylinder FOC and save a few LPg cylinders.

He can repay me in beer

[nowty]

I deal with excess solar by,

1) Home battery becomes near full and the DC coupled charge controllers will simply throttle off and shut down.

2) First 4kW excess gets exported, any more excess gets diverted to pump power into storage heaters and/or hot water tank.

3) If I’m out, any further excess gets exported up to 5kW, thereafter the SMA Sunny Manager throttles the grid tie inverters to keep at a constant 5kW export plus whatever the house is using.

4) If I’m in, then its preferable to prevent the home battery getting too full to keep the DC charge controllers in business. On crazy summer days there can be 10kW or 12kW coming in so I turn on the EV chargers and set them to whatever allows max export. I also look ahead at the forecasts, so if it looks really good, I might need to dump some of the home battery stack to the grid overnight to allow empty space in the home battery the next day and I turn the charge rate down to allow the max export early in the day.

With the obscure higher export rebates compared with cheap rate import, I no longer worry about a low home or EV battery at the end of the solar day as it’s cheaper to import overnight and export as much during the day.

[Colin Deng]

I have this problem with my extra Hoymiles PV - where the voltage goes above 253 during exporting and it trips out.
I have reduced the charge current for the batteries to try and spread out the charging time, but at the moment, the battery doesn't discharge that much overnight, so can only help a little bit.
I've also capped the export at 3.4kW in the Sunsynk system with CT coil, rather than the maximum setting of 3.9kW, in the hope of reducing the peak voltage during sunny days.
It still tripped out most days over the past couple of weeks - but in most cases not for too long.
It's frustrating

Microinverter issue: If the problem is isolated to a single panel, it could be a faulty microinverter ?