Grid over voltage shutting down my PV array

[JohnV6]

Our PV solar keeps shutting down as the DNO supply via Last Mile Asset Management is going over voltage i.e. over 230V +10%. If the grid exceeeds 253 V the pv solar is not legally allowed to export.

It has happened before , they denied it but mysteriously it was sorted.

On the Money Saving Expert forum it seems quite a common issue.


Are others on here having / had the same problem & how did you fix it?

I'm particularly interested if Last Mile is you DNO and or you live in the IP11 post code area

 

[Bam Bam]

I haven't experienced it, but I think that this video might be about a similar case:


I'm guessing there is a lot of solar in your area and it happens on sunny days?

 

[JohnV6]

Correct there is a solar farm as well about 1 mile away across the A14.
The video was very helpful. Thank you for posting it

 

[Bam Bam]

Correct there is a solar farm as well about 1 mile away across the A14.
The video was very helpful. Thank you for posting it

Glad it was useful. Hopefully you can get it investigated by the DNO and sorted.

I don't know if it would make a difference to charge your car up on the sunniest days (and ask your neighbours to do the same).

 

[JohnV6]

Sadly not as PV stops if the grid is over voltage.
Here is yesterdays horrible result. You can see I lost at least 12kWh.

 

[Bam Bam]

Sadly not as PV stops if the grid is over voltage.
Here is yesterdays horrible result. You can see I lost at least 12kWh

How frustrating.

I don't suppose charging the car on full will bring the local voltage down then, I guess you'd need to be charging a large number of cars for it to bring down the voltage level.

You aren't too far from Artisan electrics who could perhaps pick up your issue if you own installer and DNO refuse to do anything about it. They are expensive 'artisans' though. Maybe if they can get a video out of it they will give you a discount or something!

Off grid option?
Do you have the facility to island yourself from the grid? Perhaps then you could run off the solar, but it isn't ideal. We'd have to do it manually and we'd have very limited power available in backup mode (16a total, not the usual 100a).

 

[Rolfe]

Jeez, that's terrible. I would be going screaming banjax if that was happening to me. (Yesterday for me. 48.5 kwh.)

 

[MG4ismycar]

Our PV solar keeps shutting down as the DNO supply via Last Mile Asset Management is going over voltage i.e. over 230V +10%. If the grid exceeeds 253 V the pv solar is not legally allowed to export.

It has happened before , they denied it but mysteriously it was sorted.

On the Money Saving Expert forum it seems quite a common issue.


Are others on here having / had the same problem & how did you fix it?

I'm particularly interested if Last Mile is you DNO and or you live in the IP11 post code area

Yes. I have the same issue.
6.8 kWp solar capacity on roof often creating over voltage, which shuts off my Zappi.
Being restricted on export as well for same reason.
The nearby transformer was installed in the 1960s....

 

[Bam Bam]

Yes. I have the same issue.
6.8 kWp solar capacity on roof often creating over voltage, which shuts off my Zappi.
Being restricted on export as well for same reason.
The nearby transformer was installed in the 1960s....

How annoying - presumably charging the car is reducing the voltage!

 

[JohnV6]

Greenscape Energy tell me they will get Solis to upgrade the firmware as they think the alarms could be false.

 

[Deep purple]

The DNO limited me to 5KW export despite having capability for 7KW. My son very close to me made the decision to go 3 phase as he has 8 KW array, batteries, 22KW charger 3 heat pumps etc. He doesnt have any limits.
At previous house we suffered from huge voltage spikes but eventually the DNO reduced the supply transformer tapping down a step which resolved the problem.

 

[Everest]

Are others on here having / had the same problem & how did you fix it?

We did initially - and we're also with UKPN in East Anglia. UKPN responded very quickly when we reported >253V; as the DNO must conform to ESQCR 2002 regs.

See also my posting here...
MG4 not charging

We also have Solis inverters - check the Solis screen for OV-G-V alarms
see also OV-G-V Alarm

Assuming your Solis is correctly configured for UK G98/G99 grid compliance it should cut off (IIRC) if it detects AC-grid voltage over 258V for 5s or over 262V for 500ms. Note, this is the voltage at the Solis inverter which, when exporting, will be greater than the grid voltage at your DNO fuse depending on cable size and length to the Solis, due to voltage-rise on the line.

If the voltage at the DNO fuse is > 253V at any time that you are exporting 3680W or less, then UKPN should promptly address the issue. They may put some monitoring equipment by your CU for a week or two. Fixing the issue is done by them reducing the tap on their 11kV to LV transformer by one or more 2.5% steps. If the LV transformer is very old (ours was) it will get replaced.

FYI: Weekend pm's and around 1 to 2am any day seem to be the highest voltages around here.

 

[Everest]

P.S pm me if you want more details / help

 

[Everest]

Greenscape Energy tell me they will get Solis to upgrade the firmware as they think the alarms could be false.

Really? I smell BS. I have been using Solis inverters for 3 years and regularly in touch with many Solis users on a solar forum and never come across that as an issue. Ginlong Solis are the world's third-largest PV inverter manufacturer - I think detecting voltages is bread and butter to them.

Now, if Greenscape Energy haven't configured your inverter correctly - that's a different issue