PMM (Pico Mains Monitor)

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Joined: 05/10/2019
Location: United Kingdom
Posts: 1526
Posted: 12:40pm 15 Sep 2021      

From what I understand (we used to install PV systems in the UK) the domestic side isn't a big problem. That's because in most cases the arrays are relatively small compared to the load. There will be excess generation sometimes, but it's not enormous.

The PV inverter usually tracks the grid voltage to only allow a certain amount of feed-in, no matter what the conditions are. Many will keep it low or non-existent until the locally connected load is satisfied because if you don't do that you are paying for electricity at a higher rate than you can get paid for generating it.  

Industrial consumers, with large arrays, have to have export restriction in place, otherwise their DNO will be round to disconnect them! That's because they are capable of affecting distribution wiring and protection equipment on the network through over-generation. There is a set of specific equipment that has to be installed on those sites or they won't get connected.

Severe over-volt problems in the UK are usually caused by local problems, such as a large factory shutting off some big loads or complaints about low voltage off one sub (maybe because of a new housing estate) turning into complaints about high voltage on another. Both those usually get fixed eventually, but it might be when new subs get installed or older ones updated or readjusted. It's worth telling your DNO if there are frequent over-voltage issues. I know of an area not far from here who do have a problem, but they are right on the sub feeding a huge factory complex. Short of moving the domestic stuff onto a different HV line it's not likely that their problem will get fixed.
Edited 2021-09-15 22:42 by Mixtel90