Energy infrastructure

We have been having multiple Brownouts recently . The latest had the grid running at 80volts for about 2 minutes before the fault was detected by the Esb and cutover. Blackout lasted about 4 hours. There was some bad nosies coming from various plant and equipment in the house during the brownout. When fault appeared on Esb it was at closest substation and affected a couple of thousand customers.

I'm wondering what is the most likely reason for these brownouts. I suspect since we are just gone into a period of high pressure, wind isnt blowing and grid is struggling to meet base load. We are in area plastered with turbines and no power stations.

What's the best way to protect equipment? Thinking UPS and what's involved in getting fitted. Would just need for a couple of mins so things like my home server can shut down gracefully.

Would a grid drop from 230v to 80v be a symptom of an overloaded supply? That was the reading on my inverter for a few minutes while the Brownout occurred until cutover to blackout from the substation. It happened around 9pm so Solar is out of the question and since we are in high pressure weather wise the turbines aren't producing. Supply wise It would be surprising if someone upstream in our area decided to fire up a bunch of diesel generators randomly but ya on the load side maybe there is dairy farms on residential supply's causing supply issues. I'd be interested to see load figures on the grid around the time it was occurring if that is available publicly

Yes, low voltage is a symptom of overloaded supply. Power, resistance (the load), voltage and current are all linked. If you try to draw too much current from a supply, its voltage will drop - that's as true of a 1.5 volt battery as a 120 kV link. When I say “overloading” the supply, I don’t mean putting voltage onto the line; I mean drawing more current from the line than the supply can provide. So it wouldn’t be a neighbour turning on generators, but it could be a neighbour with some kind of machinery that is faulty, or drawing too much power. (A neighbour of a family member was running a busy arc-welding and cutting workshop off a single-phase domestic supply, which was great fun for everyone further away from the substation - it took years to get them to sign up for a three-phase industrial supply).

But I still don’t understand why you keep coming back to solar or wind power as the cause, especially when you also said ESB are reporting a fault at the substation.

Not sure if this should go here or in a Renewables thread.

Obviously quite a bit of solar today, but I'm more interested in a couple of things we can see on the Demand graph and not the Utility Solar.

https://www.eirgrid.ie/grid/real-time-system-information

The first one occurs at 2:15 where the demand jumps from 4101 to 4230 GW. Many EV electricity plan windows start at 2am and I believe that spike is the nation topping up its domestic batteries.

Peak morning demand was at 8:15 and was 5456 GW. During the day it has dropped to 4371 GW at 14:00. Most of that is due to domestic solar. That is a seriously impressive dip.

On sunless days, the drop from morning peak to mid afternoon is in the region of 150-200 GW

so on a day like today it's not unreasonable to estimate that 900 MW is being generated domestically. SEAI have said that domestic solar applications doubled yoy in March so the overnight trough will soon disappear and the early afternoon trough will be even more significant on sunny days.

P=VI

If power is constant and current is increased, V must be smaller.