6 ms·

I 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 t

by guerby 7y ago

I 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 ago
Batteries 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 ago
  Interesting! 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 ago
    Skinny, 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.
    - caf 7y ago
      In a sense this is 'virtual inertia', since your local control systems are configured to resist a change in frequency. Presumably you need comms later to add up how much frequency support you ended up providing, for market settlement?
wongarsu 7y ago
Pretty much the only plants you can get to full power in such a short notice are battery or hydroelectric. Even pumped-storage hydro typically takes 10-30 seconds to full power because of inertia. Batteries are much more expensive, but as close to instant as it gets.
- jacques_chester 7y ago
  Other fast responders are supercapacitors, superconductor magnetic energy storage, flywheels, compressed air and there probably a lot more I don't know about. What conventional chemical batteries have is mostly that they are manufactured in vast quantities, so the unit costs are constantly improving.
barney54 7y ago
Yes, batteries are very fast acting, but that battery in South Australia is only 100MW and the grid lost over 1400 MW. https://www.news.com.au/technology/innovation/inventions/everything-you-need-to-know-about-teslas-battery-in-south-australia/news-story/a989f74cfccb8a1211de83f5becc60ed https://www.news.com.au/technology/innovation/inventions/eve... Batteries have a lot of potential, but they are currently small in capacity.
- guerby 7y ago
  According to the article it was a cascade of events and the last one was the 244MW gas turbine going out that lead to the collapse so not that far from current scale grid batteries. Also battery reacting instantaneously to correct or mitigate a grid issue might avoid some other generator to go offline or allow to go offline for a must shorter amount of time avoiding some of the cascading effects. It seems to me that the value of grid batteries is not just the nameplate capacity compared to other generation technologies, it is a class on its own. May be once batteries are incorporated in the grid at some scale software triggers commanding other generators capacity disconnect/reconnect will have to be updated "let the grid batteries do their job first and then act".
- jhayward 7y ago
  > but that battery in South Australia is only 100MW and the grid lost over 1400 MW I hear this kind of misconception fairly often and so it is worth noting that you don't need 1400 MW of battery to protect from this event. The initial 735 MW drop happened, as I read TFA, when a major generating source took itself offline as a result of the frequency disturbance. The later generator drops are cascades of the frequency disturbance earlier in time. If a suitable battery had been present and reacting in milliseconds it could have stabilized the frequency enough, for just the very short period required, to avoid the whole generator trip in the first place. Thus you can use much smaller amounts of fast-response frequency support to avoid much bigger drops. This is how batteries can pay for themselves so quickly when placed in the right topologies w.r.t to the grid demand and generation resources.
  - generatorguy 7y ago
pm215 7y ago
Battery systems seem likely to play a greater part in the grid in future, but I think it's worth noting that the problem here was "sudden loss of generation exceeded the amount that the system operating specs require to be covered by having alternatives on standby". So unless we're collectively prepared to pay to raise the resilience by having more standby capacity, might we just find ourselves with more batteries and fewer turbines running inefficiently at half-load, so we take the benefit of battery tech in cheaper electricity rather than reduced chances of outage?

by guerby 7y ago

mitchoneill1 7y ago

Batteries 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 ago
Interesting! 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 ago
  Skinny, 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.
  - caf 7y ago
    In a sense this is 'virtual inertia', since your local control systems are configured to resist a change in frequency. Presumably you need comms later to add up how much frequency support you ended up providing, for market settlement?

wongarsu 7y ago

Pretty much the only plants you can get to full power in such a short notice are battery or hydroelectric. Even pumped-storage hydro typically takes 10-30 seconds to full power because of inertia. Batteries are much more expensive, but as close to instant as it gets.

jacques_chester 7y ago
Other fast responders are supercapacitors, superconductor magnetic energy storage, flywheels, compressed air and there probably a lot more I don't know about. What conventional chemical batteries have is mostly that they are manufactured in vast quantities, so the unit costs are constantly improving.

barney54 7y ago

Yes, batteries are very fast acting, but that battery in South Australia is only 100MW and the grid lost over 1400 MW. https://www.news.com.au/technology/innovation/inventions/everything-you-need-to-know-about-teslas-battery-in-south-australia/news-story/a989f74cfccb8a1211de83f5becc60ed https://www.news.com.au/technology/innovation/inventions/eve... Batteries have a lot of potential, but they are currently small in capacity.

guerby 7y ago
According to the article it was a cascade of events and the last one was the 244MW gas turbine going out that lead to the collapse so not that far from current scale grid batteries. Also battery reacting instantaneously to correct or mitigate a grid issue might avoid some other generator to go offline or allow to go offline for a must shorter amount of time avoiding some of the cascading effects. It seems to me that the value of grid batteries is not just the nameplate capacity compared to other generation technologies, it is a class on its own. May be once batteries are incorporated in the grid at some scale software triggers commanding other generators capacity disconnect/reconnect will have to be updated "let the grid batteries do their job first and then act".
jhayward 7y ago
> but that battery in South Australia is only 100MW and the grid lost over 1400 MW I hear this kind of misconception fairly often and so it is worth noting that you don't need 1400 MW of battery to protect from this event. The initial 735 MW drop happened, as I read TFA, when a major generating source took itself offline as a result of the frequency disturbance. The later generator drops are cascades of the frequency disturbance earlier in time. If a suitable battery had been present and reacting in milliseconds it could have stabilized the frequency enough, for just the very short period required, to avoid the whole generator trip in the first place. Thus you can use much smaller amounts of fast-response frequency support to avoid much bigger drops. This is how batteries can pay for themselves so quickly when placed in the right topologies w.r.t to the grid demand and generation resources.
- generatorguy 7y ago

pm215 7y ago

Battery systems seem likely to play a greater part in the grid in future, but I think it's worth noting that the problem here was "sudden loss of generation exceeded the amount that the system operating specs require to be covered by having alternatives on standby". So unless we're collectively prepared to pay to raise the resilience by having more standby capacity, might we just find ourselves with more batteries and fewer turbines running inefficiently at half-load, so we take the benefit of battery tech in cheaper electricity rather than reduced chances of outage?