Voltage variations.

Mine is nominally 233v. Over the last 2 weeks the minimum was 220 and the maximum 242.

Supply should not exceed 253v even if you are a micro-generator. Tell your supplier and the should arrange for the voltage to be reduced, possibly after having monitored the supply for a few weeks.

OTOH he PV meter may be badly calibrated

There is a Kwh meter on the inverter and it does not agree with the "real" meter. It shows less. One would think if it was showing a higher than correct voltage, it would show more (KWh than the "real meter". that is).

I have been monitoring the effect of stuffing current back into the mains. I think at maximum output ( 3.88Kw), it causes the mains voltage to rise by around three volts.

so 3 volts over 16 amps, near enough, gives a little under 0.2 ohms. That's an entirely plausible and very typical value for the mains impedance at the supply terminals. That will be predominantly resistive

- just the resistance of the mains cable from the substation and your service cable. Applying I^2*R shows that about 50 of your nice solar watts are just heating up the ground.

Provided it has been registered by the generation meter it does not matter how much is wasted. Such stupidities arise under FIT!

Bob

No that is incorrect. Most/all of the power I generate is used by my nieghbours. This reduces the load on the grid and the power/current supplied from the power station and hence increases efficiency. Instead of the power being transmitted for miles, it's only a few yards. Savings can be as much as 2%.

In article , harry scribeth thus

the country Harry;?...

Sunday afternoon, it's running at 236 to 237v.

I understand the UK tolerance specification was 240V RMS +/-6%, i.e. approx 226-254v. Now, however, following harmonisation across Europe it is 230V+10%, -6% i.e. approx 216-253v.