7 ms·

"Frequency drops below 48.8Hz which triggers the Low Frequency Demand Disconnection scheme (LFDD). Approximately 1GW (5% of total) of Great Britain electricity

• mytailorisrich 7y ago
  The issue with this specific outage is that it was badly managed. The main gripe people and authorities have with what happened is that key infrastructures immediately lost power. When (only) 5% of demand is turned off this should not impact railways, airports, and hospitals. Beyond the initial loss of power other problems amplified the consequences: For example, trains could not just restart but required specialist staff to attend each of them to get them through a specific procedure, which turned a short power loss into hours of delays. This highlights the importance of looking at systems globally. The grid is just one part of the system.
  • Zenst 7y ago
    Most situations/responses to an issue in hindsight can always be managed better, being able to have a cookie-cutter solution that fits most cases is better than none. THough I'm sure such plans will be refined - leasons learned. Thing is, a solution today might not be best for tomorrow as the grid's usage is not static, new this and that are added so the impact changes. It is interesting that you mention the inability for trains to restart. That was educational and was due to some new trains and showed that the drivers did not have the skills to in effect - reboot the trains from a cold start. So less a grid fault and more a case of that it never happened before so the result was less prepared. Interestingly the previous generation of trains did not have this issue, which may explain why it got overlooked as something that needed attention until such an event like this. As for hospitals, they all have backup generators, though if that generator fails to kick in as was the case in one I read about, that can and will cause issues. Again, may be a case of never needing it before and the combination of that and regular checks/tests presented the problem. Remember - nothing is perfect, and many lessons (as with any outage in all walks of life) will be learned from this as with all previous outages. But equally have to remember that whilst you can have the same combination of events happen in say 5 years time and have a response that works for that combination learned from the last time. Things change, like that new housing estate attached to the grid, small nuances like that could change everything or nothing. You just don't know. Heck, could be newer issues, suddenly find that you have thousands of electric cars being charged at the time you cut them off now feeding back small amounts of electricity back into the grid as they never expected to loose power without a physical disconnect.
    • mytailorisrich 7y ago
      All the issues I mentioned are obvious, and so are the potential problems you describe. This is not a question of "it's easy to say in hindsight" as these are the key issues that must be covered by standard planning. This blackout made a lot of noise because of this (apart from the actual disruption, obviously).
      • tripzilch 7y ago
        Do you have background in the field of giant power supply fault tolerance backup mishap management strategies, or something? Or are you just stating and assuming all of this is obvious, covered by standard planning, instead of easy to say in hindsight? Cause you're making a lot of statements, saying it is such, without backing it up. Maybe it is super obvious, but personally I'm impressed by the strategies that were in place.
        • mytailorisrich 7y ago
          Would you not prioritise an airport, a hospital, the railway, over residential areas? Do you not think that trains should be able to resume ASAP? Do you not think that "it never happened before" is not a valid reason to be unprepared? Do you not think that "we never had to use it before" is not a valid reason to explain why an emergency generator might not work when needed? What backing up do you need?
          • Zenst 7y ago
            "Would you not prioritise an airport, a hospital, the railway, over residential areas?" Yes and they do. As mentioned, things get added to the grid all the time, case of the airport was that it was not on a priority list. Yes that is an oversight, but who's fault and accountability we do not know. The onus would of been in the airport to inform the power distribution and if that failed to happen then the airport would be the ones with the hands up, if they was and the distribution failed to add it, then their hand would go up. But hospitals as I mentioned operate and a designed and planned for such issues with them having backup power supplies. Which is the solution for many installations as many will not have or justify the cost of being upon their own distribution spur. As for the "we never had to use it before" that's down the testing and covered in previous comments fairly well without repeating it again. But if you wish to focus upon being able to point a finger at somebody and say it is there fault, then fine. But I and I'm sure many others would not be focusing upon that, though I can appreciate that mentality due to the way media/tabloids cover such and all issues in life. After all, power cuts today are not that common on this scale, decades past and in less developed countries they would be so common that they wouldn't even make the news. But remember, if the weather forecaster says it will not rain and you go out and a light shower makes you wet - would the forecast be wrong or would we have the mentality to go, that mistake was within acceptable parameters and just one of those things. It gets down to what we are used to and what we accept. So yes, I get that blame need to be lain in many eye's but is that fair all the time? But then - nothing is perfect - better to focus on getting closer to perfection than expending energy stagnating as too busy pointing the finger.
  • pm215 7y ago
    A lot of the headline grabbing stuff wasn't the grid's fault though: * the railways didn't have traction power disconnected -- but one type of (new) train saw the within-specification frequency drop, shut down, and in many cases needed a fitter to go out and restart it. Everything else behind a dead train was stuck. I imagine the train company are discussing this with their supplier... * Ipswich hospital had a power outage, but that was because their own systems disconnected from the grid when they saw the frequency drop, and then they had a problem with one of their generators. *One regional airport seems to have been accidentally not on the list of key sites not to disconnect -- sounds like an admin snafu, and has now been fixed. None of these seem like "bad management" -- they are a collection of relatively minor, entirely unrelated, problems of the sort you're likely to run into if you have to activate an emergency procedure you haven't needed to use in a decade.
    • mytailorisrich 7y ago
      I did mention the railways and indeed the importance of making sure the whole system can cope, which means what you list in addition to the grid in isolation. > None of these seem like "bad management" They do seem like bad management because to me it looks like these issues were not taken seriously. > problems of the sort you're likely to run into if you have to activate an emergency procedure you haven't needed to use in a decade. That's bad management right there if an organisation's emergency procedure has been collecting dust for a decade.
      • DanBC 7y ago
        > They do seem like bad management. But not bad management by the Grid.
        • mytailorisrich 7y ago
          Including by the grid because key infrastructures did lose power. But in general a worrying aspect of what happened is that there seems to have been oversights all over the place (grid, hospitals, railways, etc).
  • wongarsu 7y ago
    Here in Germany large industrial customers often get a cheaper electicity price in return for being the first to be cut in a load shedding scenario. If you are something like a steel mill then cheaper electicity quickly pays for slightly more frequent blackouts; and everyone else gets a more stable electricity network.
    • timthorn 7y ago
      That's the case in the UK too.
  • deleted 7y ago
    [deleted]
  • jimmaswell 7y ago
    A potential argument against transit reliance, or at least trains relying on the grid to keep running (instead of using batteries or diesel). Personal transport options (cars, bikes, horses) are a decentralization success story when the grid goes down.
    • Zenst 7y ago
      It may well be that cars with large batteries enable a smarter grid that can store surplus generation at off-peak and buffer the peaks better. After all - not everybody drives their car at the same time, and some access to a cheaper rate of electric for allowing your car to be used in such a way when it is plugged in, is certainly one avenue that may well open up more, as we see more and more electric cars. Though the swappable battery charger offerings do seem to be more suited in accommodating such avenues and removes the worry of battery lifetime cycles from the owners. Worry that their car acts as a grid battery for a month when on holiday and reduces it's life beyond the cost of saving. So will be a case of getting the balance right. Hence I feel the swappable battery offerings may be at an advantage here and opens up making such solutions more cost effective to run.
  • NeedMoreTea 7y ago
    You're misunderstanding how it went. The 5% that's mentioned as the Low Frequency Demand Disconnection scheme, who were disconnected in managing the incident, is a scheme where very high volume users (those who have a meter reading taken every hour) voluntarily opt to have interruptible supply for better prices. When the grid needs to, they're given a power cut that they signed up for. Commonly used by big manufacturers, smelters etc. It's in their contract, expected and gets them lower electricity bills. It helps prevent the grid tipping into catastrophic shutdown when there's no backup generation left, or something major has tripped, as part of demand management. If it hadn't happened the consequences would have far more headline-worthy. Railways, hospitals and the like that encountered issues were part of "the rest". That is not part of the 5% turned off, but the small part of the 95% "rest" that can't cope with some (larger than usual) drop of frequency. If they're buying trains that can't cope with a frequency slump or backup systems that aren't tested that's outwith grid control. That's a sign their systems need to be improved, and tested properly too.
• StreamBright 7y ago
  It also highlights one of the most important characteristics of energy grids: frequency sensitivity.