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Hey! (author of the article here). I'm not happy with how I phrased this with the 4GW of capacity -- and while I suspect generation could have increased by hund
by mitchoneill1 7y ago
Hey! (author of the article here). I'm not happy with how I phrased this with the 4GW of capacity -- and while I suspect generation could have increased by hundreds of MW within 60 seconds I may be wrong. I've updated how I've phrased it in the blog to hopefully give a bit more clarity to my position.
I don't meant to suggest that plants could ramp full within 60 seconds, it's that 4GW means there's a bunch of headroom, and that there was at least the physical possibility that dispatch instructions to increase generation/start-up (the reserves were "available") could have been sent out and plants could have started moving on an upward trajectory, creating even a few extra hundred MW of generation if many of the more flexible plants (gas, hydro) could increase their output even just a bit.
Here in Australia we dispatch on a 5 minute period, and there are some plants that are very slow moving and have to ramp over tens of minutes or hours, but moving grid-wide generation up and down many hundreds of MW within a 5 minute dispatch period is a common occurrence, and so this coupled with the relatively high amount of reserve makes me suspect it would have at least been physically possible to increase output and hasten the return to a normal operating frequency.
How you create both the systems and market structures/rules to oversee dispatch and coordination of something like that in a fast and automated way is very complex and infeasible to effectively do any time soon, but I think it's a system we should be thinking about and moving towards.
Overall though I'm just grumpy about the amount of manual, slow work that's still involved in grid operations (when we lose an inter-connector here in Australia it takes 3-15 minutes for the dispatch engine to become aware that there's no inter-connector anymore as it needs to be reconfigured manually).
- guerby 7y agoI assume battery based grid power stations like the Tesla one in Australia are amongst the best in class to help in this kind of crisis situation? Compared to the gaz turbine the system it is simpler (no mehanical/heat/fluid parts) and depending on design will likely never be completely off since made of dozens or hundreds of independant equipement (batteries and inverters). Thanks for the article and comment!
- mitchoneill1 7y agoBatteries are great for this kind of stability support. I actually work for an Australian company that aggregates residential batteries together into MW-scale units and provides coordinated responses from 1,000 of kW-scale batteries that just as capable as a MW-scale plant (at a much lower cost of capital). Here's one of our plants in Canberra which is past 3MW now, and is the first of its kind to be approved to bid into our fast frequency stability markets (where you have less than a couple of seconds to respond). https://www.youtube.com/watch?v=36UJMuC9-k0 https://www.youtube.com/watch?v=36UJMuC9-k0
- guerby 7y agoInteresting! I've been following this through cleantechnica, electrek & other sites. It's transforming a complex heat/fluid/mechanical system issue into a computer network and security issue. Usually the home network internet access market is very concentrated so a failure there could make the VPP unavailable. Solvable by putting control servers in various places and having each box connecting to multiple redundant control servers hosted with diversity and redundancy in mind. Also ISM low bandwidth IoT radio technology like LoRa and sigfox might help redundancy too. Might become important is VPP grows beyond handling rare grid events.
- mitchoneill1 7y agoSkinny, cheap comms such as LoRa would be perfect for redundancy. If you can at least get a simple message to the batteries (charge/discharge at xkW) you still have most of your effectiveness of the system. One nice thing though is many of the stability services (such as balancing frequency) can be detected locally and therefore centralised dispatch and comms aren't necessary. All of our household systems have high speed metering attached (sampling at 20hZ) and when they make a frequency measurement outside the normal operating range (48.8Hz - 50.2Hz) they discharge/charge respectively. This means that when there's an event we have all the systems reacting in a way that looks coordinated, but is actually just syncronised (as they all essentially have the same input -- grid frequency), so services like this are extremely resilient.
- trebligdivad 7y agoI suspect it being evening peak made it worse, because that's peak time, so I think in normal operation they're discharging some of the batteries/pump storage that's taken up some of the spare capacity during the day. I would encourage more people to read the actual interim report - it's quite detailed with lots of detail about the frequency measurement and trips.
- 7952 7y agoIs grid frequency not a good enough signal in its own right to increase production?
- generatorguy 7y agoIt is a perfectly good signal to increase production.