Would people have a look at their stats for 1/12/25 please? Mine are showing that our grid voltage was adjusted down by about 6v from what was a nominal 248v to around 242v at 4pm that day and it has stayed down. I am pleased about this as if it is permanent then I have much greater headroom when exporting energy as previously I had my battery inverter shutdown with over-voltage when my solar inverter was exporting 6kW in the summer.
Windy Miller
I hope this helps. Steve
No change here in North Wales. Still 248v same as all November. Would appreciate a 6v reduction.
Low in Norfolk 
In my corner of North Wales yesterday from the grid's transformer on the pole I had a min of 227.7v and a high peak of 242.5v
Originally when I had my system installed I was regularly getting peaks in grid voltage over 253v and interfering with export and car charging.
The grid has a legal obligation to keep the grid voltage supplied to your house between 216v-253v and you can get them to test your supply. This can mean monitoring your house for a few days and if they see it going out of range then adjust the local step down transformer. How many houses that effects depends on your location.
In my case the transformer only supplies ,my house and one other but we are way out beyond the rhubarb.
No change here. Mayhe someone reported an over voltage and a tweak has been done.
No change here in rural Bedford. Still bouncing around 250V.
We are second house from the substation on our phase and the first house has a big solar array which pushes everything up.
Had to install a Variable transformer on my lathe to stop its overvoltage alarms (it does not like over 245V).
PaDav6
252V+ is over voltage.
I had that and the EV charger folks said report it to the DNO (the EV charger kept shutting down). EV company provided dates and times the EV charger had logged over voltage and DNO leapt into action and reduced the voltage locally.
Thanks everyone.
So I think I have a local change. I requested this 2.5 years ago as I was regularly seeing 258v on sunny days. Because they only measured a nominal 248v when they did their test they said it was in spec. and wouldn't add a monitor to see what I was reporting. Maybe enough others have now reported the problem that they've decided to drop the voltage so now I am seeing a permanent 242v nominal. I'm in a town in Bedfordshire so it wasn't because of long overhead lines. I think the local grid connection hasn't had an adjustment at the substation since it was set up many years ago.
I believe a country-wide change is coming. As they want to harmonise a bit closer to the 230v there is a plan to drop by around 5v in 2 steps. Don't know when they might do this though.
https://www.efixx.co.uk/Articles/Proposed-Changes-to-UK-Mains-Voltage-Limits-Explained
Less than an hour after reporting voltage spikes to UK Power Networks an engineer arrived to measure the voltage.
Next step if for to fit a recorder for a week.
Interestingly the GE recorded grid voltage was 2V higher than than the engineer measured. (248.6V at meter and 250.8V on the invertor)
PaDav6 Interestingly the GE recorded grid voltage was 2V higher than than the engineer measured. (248.6V at meter and 250.8V on the invertor)
GE equipment is not accurate!
These are surprisingly accurate for the price, and rather useful too.
https://www.amazon.co.uk/dp/B07R6NBZ9T
Windy Miller I am not sure how they might manage that. I guess it is OK in more populous areas where there will be many houses off sub-station supplies but in rural areas like where I am there are just 2 houses hanging off a pole mounted transformer directly stepping volts from a 600v (it might be 800v) line. There must be thousands of these in North wales. Many of which are getting long in the tooth and have no remote adjustment. I know ours has an installation date of 1962! I was told by a DNO engineer there are some dating back to the 1950s.
I am not sure a universal voltage drop will do much good in some cases. In the winter we can see a minimum voltage of around 220v so dropping another 5 volts in that situation could drop the voltage too far.
I’m also in Bedfordshire, in a small village. I did have the DNO out about 18 months ago when I was getting repeated high grid voltages which were pushing the inverters to stop generating. They set monitoring in place and agreed that it was over voltage and they’d rectify it. Half our village then got leafleted about the 10 minute power outage that would occur whilst they did ‘essential maintenance to equipment’. I didn’t tell anyone else that it was me causing it!
This summer I have noticed more high grid voltages and assumed it was due to both my solar and other solar in the village. Looking just now I am seeing spikes over 253V including a regular 4am spike which must be something else on the grid coming online at that time.
But I’m not exporting anything at the moment so these daily spikes I am seeing can’t be me. Think I will call the DNO again
Pleased to say mine is still down on what it was. Yesterday's highest voltage was 250.6v @ 13:24. Generally sitting around 242v down from 248v a few weeks ago. No problem with the son's car charger over the weekend (which used to fault on the high voltage).
Our grid voltage was 234.2 to 244.2 on the 1st December and we are about quarter of a mile from our substation.
i've had a look at mine, can see drops as low as 225V, peaks about 250V - its all over the plaec, wouldn't say i can see a definite point where things drop down so its probably somethign regional / more isolated.
Average for me seems to be in the 246-8V range
I've just realised that my Emporia monitor is also logging voltage. There is a more gradual trend downwards from a daily average of 256v on 19/11 to 239v on 18/12. There isn't a step change on 1/12 as I originally thought. I wonder if this is just seasonal?
Windy Miller I might be seasonal, we see a difference between summer and winter. In summer, our minimum will be around 230-235, but in winter it can go as low as 220-225v. Thankfully, since they adjusted our transformer, we do not exceed a max of about 248v in summer Yesterday, our min was 227v and max 241v.
On 1 December voltage between 229 (6pm as the ovens turn on) and 241 at midnight as everyone tucked up in bed. We share a central transformer, some 200m away, with around 85 houses. In fill housing and more electric cars may be causing the DNO some problem with voltage tappings on the transformer.