Path: ...!eternal-september.org!feeder3.eternal-september.org!news.eternal-september.org!eternal-september.org!.POSTED!not-for-mail
From: Martin Brown <'''newspam'''@nonad.co.uk>
Newsgroups: sci.electronics.design
Subject: Re: Grand Apagon - Electricity (not) in Spain
Date: Tue, 29 Apr 2025 20:32:22 +0100
Organization: A noiseless patient Spider
Lines: 48
Message-ID: <vur9g9$2glaf$1@dont-email.me>
References: <vuqgef$1of93$1@dont-email.me> <vuqogf$1vlqj$1@dont-email.me>
 <vuqq0c$217v6$1@dont-email.me> <vur3l4$2avav$1@dont-email.me>
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8; format=flowed
Content-Transfer-Encoding: 7bit
Injection-Date: Tue, 29 Apr 2025 21:32:26 +0200 (CEST)
Injection-Info: dont-email.me; posting-host="6bdc51d93f7a38f533795041c9e47604";
	logging-data="2643279"; mail-complaints-to="abuse@eternal-september.org";	posting-account="U2FsdGVkX1+vueLys1GiDsy+ZNh1QzAIqBBN7g5a9E5zEfLYveha3A=="
User-Agent: Mozilla Thunderbird
Cancel-Lock: sha1:6Q8cRPbvYcdN0soyTkjZh1ltA3o=
Content-Language: en-GB
In-Reply-To: <vur3l4$2avav$1@dont-email.me>
Bytes: 3277

On 29/04/2025 18:52, Don Y wrote:
> On 4/29/2025 8:07 AM, Martin Brown wrote:	

>> They try very hard not to mention the fact that their load shedding 
>> algorithm was shedding a lot of local solar PV generation along with 
>> the load so that it was playing catch up and never quite getting there.
> 
> Can they disconnect individual residential installations?

In principle they can disconnect any residential installation with a 
smart meter (although they are normally prohibited from doing so). And 
anyone with a SMETS1 "smart" meter is wide open for a bad actor to flip 
their power on and off deliberately to bring the UK network down.

https://www.bbc.co.uk/news/technology-22608085

Unclear if the smart meters from that era that have become disabled by 
the customer changing supplier are still a hacker security risk or not. 
State actors would have no trouble hacking them...

Some university researchers had no real bother!

> Or, just solar "farms"?

They can drop out entire blocks of switchgear to take a given region or 
zone offline (as would happen if a fault condition trips a breaker).

The big problem on a really sunny day is that an individual house roof 
4kW PV installation in late afternoon in the UK will be potentially 
exporting all of it to the grid. That is about 20-30 houses worth of 
electricity for each solar roof.

They drop say 100MW of load or approx 500k houses @ 200W but with 2% of 
them generating 4kW then they also drop off 40MW of local generation.

So the net load shedding is only 60MW which isn't enough to restore the 
balance and then the cycle repeats until it hits the low frequency total 
panic limiter. UK stopped it spreading by manual override dropping more 
than the algorithm wanted but leaving a big area without power.

It didn't help that by the time they did that the low frequency had put 
a lot of electric trains into a disabled state requiring a hard reset by 
a qualified service engineer visit and at random positions on the 
intercity train lines. The guys who could do that were in short supply.

-- 
Martin Brown