6 ms·

"With inverter-based power storage, generation, and transmission, the grid can now react incredibly quickly. This is good when they do the right thing, but can

by guerby 1y ago

"With inverter-based power storage, generation, and transmission, the grid can now react incredibly quickly. This is good when they do the right thing, but can be very bad when they do the wrong thing." I'm wondering if this will be like the 2016 South Australian blackout https://en.wikipedia.org/wiki/2016_South_Australian_blackout https://en.wikipedia.org/wiki/2016_South_Australian_blackout "AEMO identified software settings in the wind farms that prevented repeated restarts once voltage or frequency events occurred too often. " Grid operators are currently mostly against renewable and so they impose "blunt" disconnect rules on inverters behind renewable sources, and this comes to bite the grid when the proverbial shit hits the fan. May be in the end this will be a good thing and grid operators will start to treat inverters and renewable as a strength and modify grid regulations as needed.

reaperducer 1y ago
Grid operators are currently mostly against renewable As someone who moves a lot, it's always curious to me that grid operators vary so widely on this. Some places (like where I am now), the grid operator hates renewables and especially rooftop solar. Other places, the grid operator will actually subsidize rooftop solar because it they say it reduces the amount of generation it has to do, thus saving money on infrastructure and maintenance. Of course, each location has wildly different climates, but the regional politics aren't that different, so I don't think it's about ideology.
- shadowgovt 1y ago
  It depends heavily on their market incentives. If the local power company is also in charge of the wires, less load on the wires means less cost. In a market where distribution and generation are different operations, generation only cares about whether anyone's going to buy the electricity they want to put on the wire and you saying "No thanks, I'm full" is in direct competition to their interests (and existence as a firm).
  - idiotsecant 1y ago
    Huh? Transmission networks get directly financially rewarded for more power flowing in the form of wheeling charges. It's wild reading HN discussions of topics that I actually know about. It makes me wonder how much I can trust the discussions I don't know about.
    - pjc50 1y ago
      This is very jurisdiction-dependent, isn't it? And different for nationalized operators like the UK?
      - scrlk 1y ago
        The GB grid has a nationalised system operator (NESO). The transmission and distribution networks are privatised.
    - tekla 1y ago
      I know things about airplanes. The discussions here about airplanes is laughable, below wikipedia level.
    - ggm 1y ago
      This is definitionally "Gell-Mann amnesia" isn't it? https://en.m.wikipedia.org/wiki/Gell-Mann_amnesia_effect https://en.m.wikipedia.org/wiki/Gell-Mann_amnesia_effect
shadowgovt 1y ago
Funny enough, the effect of inverters on the grid may be mitigated with a relatively simple solution: add a flywheel to the inverter-based connection farms to "fake" a turbine. The wind or solar farm drives the flywheel and if the grid-side power starts to fluctuate, it pulls on the flywheel before the inverters feel it. You lose some total efficiency in the electrical-to-mechanical-to-electrical conversion, but get enough flywheels and maybe you don't care (because they also act as a place to store peak energy production when demand is low).
- dainesy 1y ago
  How Wind Turbines Generate Electricity 1. Mechanical to Electrical Energy Conversion • Wind Energy Capture: The wind pushes against the blades of the wind turbine, causing them to rotate. These blades are attached to a central hub, which turns a low-speed shaft. • Gearbox (in many turbines): This shaft is connected to a gearbox, which increases the rotation speed. The gearbox drives a high-speed shaft connected to the generator. • Generator: The high-speed shaft turns the rotor inside a generator. As the rotor spins inside a magnetic field, it induces a flow of electricity—typically alternating current (AC)—using electromagnetic induction. Some turbines use direct-drive generators (no gearbox), especially in offshore installations, which reduce maintenance. 2. Power Conditioning and Grid Integration • Variable Speed Generation: Wind speed varies, so the output frequency and voltage can fluctuate. Wind turbines typically use power electronics (converters and inverters) to stabilize the electricity before it’s sent to the grid. • Inverter Role: Converts variable-frequency AC or DC from the generator into grid-compatible AC (usually 50 Hz or 60 Hz depending on the region). 3. Phase Angle and Synchronization What Is Phase Angle? • The phase angle represents the timing difference between the voltage waveform of the turbine’s output and the grid’s voltage waveform. • For a generator to supply power effectively, it must match the phase, frequency, and voltage of the grid. • If the phase angle is off, power cannot flow efficiently and may even cause instability or damage. Synchronization Process • Before a wind turbine connects to the grid, its inverter adjusts the output so that: • Frequency = Grid frequency (e.g., 60 Hz) • Voltage = Grid voltage • Phase angle = Aligned with grid phase • Once synchronized, the turbine can export power. 4. Ancillary Services Provided by Wind Turbines Ancillary services are support functions that maintain the stability and reliability of the power grid. Modern wind turbines, especially with advanced inverters and control systems, can provide several key services: A. Frequency Regulation • Wind turbines can rapidly adjust output to help balance supply and demand. • This is called primary frequency response, essential when there’s a sudden change in load or generation. B. Reactive Power Support / Voltage Control • Inverters can produce or absorb reactive power, which helps maintain voltage levels on the grid. • This is important for power factor correction and avoiding voltage collapse. C. Inertia and Synthetic Inertia • Traditional turbines (like in coal or gas plants) provide rotational inertia, helping to resist sudden changes in frequency. • Wind turbines, being decoupled from the grid by power electronics, don’t naturally provide inertia. • However, some advanced systems provide synthetic inertia by rapidly adjusting power output in response to frequency changes. D. Black Start Capability • Some wind turbines can assist in black start procedures (restarting the grid after a blackout), but this is still limited and evolving.
idiotsecant 1y ago
Grid operators are, as a rule, not opposed to renewables at all. They are 'opposed' to resources that do not provide frequency support and are non-dispatchable. Renewables need storage to be well behaved. As soon as we start factoring that into the build at scale the problems go away. Generators want to ignore all the inconvenient physics of power transmission networks and just want $$$ for MW. The system doesn't work if enough people operate like that.
- guerby 1y ago
  You're completely wrong about this. Inverters if told so can do frequency support better and cheaper than any other solutions. No other technology can react as fast as an inverter. See the Texas grid grid service market which is now completely dominated by GW of inverters. https://comptroller.texas.gov/economy/fiscal-notes/infrastructure/2024/battery-store/ https://comptroller.texas.gov/economy/fiscal-notes/infrastru... "One solution is to connect inverters with “grid-forming” capabilities, which help mitigate this risk by limiting fluctuations outside of 60 Hz, increasing grid stability. Experts see utility-scale batteries as a prime opportunity to deploy grid-forming inverters to the grid, as grid-forming integration with batteries is cheaper and faster than building new transmission." "grid-forming" inverter is just software and parameters, your el-cheapo home solar inverter can do it too. It currently is prevented from doing so by ... grid operator regulations which ask it to disconnect at the first issue.
  - metalman 1y ago
    it also needs silicone carbide, which is the substance behind transformerless, inverter based grid power switching https://www.powerelectronicsnews.com/silicon-carbide-sic-enables-an-omnidirectional-grid/ https://www.powerelectronicsnews.com/silicon-carbide-sic-ena...
  - idiotsecant 1y ago
    Let's talk about how you think inverters do frequency support without storage, which was the central point of my post.
toast0 1y ago
> "AEMO identified software settings in the wind farms that prevented repeated restarts once voltage or frequency events occurred too often. " > Grid operators are currently mostly against renewable and so they impose "blunt" disconnect rules on inverters behind renewable sources, and this comes to bite the grid when the proverbial shit hits the fan. As a distributed systems person, this seems like a coordination/communication problem. If a single node is having repeated events, it may likely be broken and staying offline could be a better choice. If multiple nodes are having repeated events, maybe it's better for them to stay connection and do their best.

by guerby 1y ago

reaperducer 1y ago

Grid operators are currently mostly against renewable As someone who moves a lot, it's always curious to me that grid operators vary so widely on this. Some places (like where I am now), the grid operator hates renewables and especially rooftop solar. Other places, the grid operator will actually subsidize rooftop solar because it they say it reduces the amount of generation it has to do, thus saving money on infrastructure and maintenance. Of course, each location has wildly different climates, but the regional politics aren't that different, so I don't think it's about ideology.

shadowgovt 1y ago
It depends heavily on their market incentives. If the local power company is also in charge of the wires, less load on the wires means less cost. In a market where distribution and generation are different operations, generation only cares about whether anyone's going to buy the electricity they want to put on the wire and you saying "No thanks, I'm full" is in direct competition to their interests (and existence as a firm).
- idiotsecant 1y ago
  Huh? Transmission networks get directly financially rewarded for more power flowing in the form of wheeling charges. It's wild reading HN discussions of topics that I actually know about. It makes me wonder how much I can trust the discussions I don't know about.
  - pjc50 1y ago
    This is very jurisdiction-dependent, isn't it? And different for nationalized operators like the UK?
    - scrlk 1y ago
      The GB grid has a nationalised system operator (NESO). The transmission and distribution networks are privatised.
  - tekla 1y ago
    I know things about airplanes. The discussions here about airplanes is laughable, below wikipedia level.
  - ggm 1y ago
    This is definitionally "Gell-Mann amnesia" isn't it? https://en.m.wikipedia.org/wiki/Gell-Mann_amnesia_effect https://en.m.wikipedia.org/wiki/Gell-Mann_amnesia_effect

shadowgovt 1y ago

Funny enough, the effect of inverters on the grid may be mitigated with a relatively simple solution: add a flywheel to the inverter-based connection farms to "fake" a turbine. The wind or solar farm drives the flywheel and if the grid-side power starts to fluctuate, it pulls on the flywheel before the inverters feel it. You lose some total efficiency in the electrical-to-mechanical-to-electrical conversion, but get enough flywheels and maybe you don't care (because they also act as a place to store peak energy production when demand is low).

dainesy 1y ago
How Wind Turbines Generate Electricity 1. Mechanical to Electrical Energy Conversion • Wind Energy Capture: The wind pushes against the blades of the wind turbine, causing them to rotate. These blades are attached to a central hub, which turns a low-speed shaft. • Gearbox (in many turbines): This shaft is connected to a gearbox, which increases the rotation speed. The gearbox drives a high-speed shaft connected to the generator. • Generator: The high-speed shaft turns the rotor inside a generator. As the rotor spins inside a magnetic field, it induces a flow of electricity—typically alternating current (AC)—using electromagnetic induction. Some turbines use direct-drive generators (no gearbox), especially in offshore installations, which reduce maintenance. 2. Power Conditioning and Grid Integration • Variable Speed Generation: Wind speed varies, so the output frequency and voltage can fluctuate. Wind turbines typically use power electronics (converters and inverters) to stabilize the electricity before it’s sent to the grid. • Inverter Role: Converts variable-frequency AC or DC from the generator into grid-compatible AC (usually 50 Hz or 60 Hz depending on the region). 3. Phase Angle and Synchronization What Is Phase Angle? • The phase angle represents the timing difference between the voltage waveform of the turbine’s output and the grid’s voltage waveform. • For a generator to supply power effectively, it must match the phase, frequency, and voltage of the grid. • If the phase angle is off, power cannot flow efficiently and may even cause instability or damage. Synchronization Process • Before a wind turbine connects to the grid, its inverter adjusts the output so that: • Frequency = Grid frequency (e.g., 60 Hz) • Voltage = Grid voltage • Phase angle = Aligned with grid phase • Once synchronized, the turbine can export power. 4. Ancillary Services Provided by Wind Turbines Ancillary services are support functions that maintain the stability and reliability of the power grid. Modern wind turbines, especially with advanced inverters and control systems, can provide several key services: A. Frequency Regulation • Wind turbines can rapidly adjust output to help balance supply and demand. • This is called primary frequency response, essential when there’s a sudden change in load or generation. B. Reactive Power Support / Voltage Control • Inverters can produce or absorb reactive power, which helps maintain voltage levels on the grid. • This is important for power factor correction and avoiding voltage collapse. C. Inertia and Synthetic Inertia • Traditional turbines (like in coal or gas plants) provide rotational inertia, helping to resist sudden changes in frequency. • Wind turbines, being decoupled from the grid by power electronics, don’t naturally provide inertia. • However, some advanced systems provide synthetic inertia by rapidly adjusting power output in response to frequency changes. D. Black Start Capability • Some wind turbines can assist in black start procedures (restarting the grid after a blackout), but this is still limited and evolving.

idiotsecant 1y ago

Grid operators are, as a rule, not opposed to renewables at all. They are 'opposed' to resources that do not provide frequency support and are non-dispatchable. Renewables need storage to be well behaved. As soon as we start factoring that into the build at scale the problems go away. Generators want to ignore all the inconvenient physics of power transmission networks and just want $$$ for MW. The system doesn't work if enough people operate like that.

guerby 1y ago
You're completely wrong about this. Inverters if told so can do frequency support better and cheaper than any other solutions. No other technology can react as fast as an inverter. See the Texas grid grid service market which is now completely dominated by GW of inverters. https://comptroller.texas.gov/economy/fiscal-notes/infrastructure/2024/battery-store/ https://comptroller.texas.gov/economy/fiscal-notes/infrastru... "One solution is to connect inverters with “grid-forming” capabilities, which help mitigate this risk by limiting fluctuations outside of 60 Hz, increasing grid stability. Experts see utility-scale batteries as a prime opportunity to deploy grid-forming inverters to the grid, as grid-forming integration with batteries is cheaper and faster than building new transmission." "grid-forming" inverter is just software and parameters, your el-cheapo home solar inverter can do it too. It currently is prevented from doing so by ... grid operator regulations which ask it to disconnect at the first issue.
- metalman 1y ago
  it also needs silicone carbide, which is the substance behind transformerless, inverter based grid power switching https://www.powerelectronicsnews.com/silicon-carbide-sic-enables-an-omnidirectional-grid/ https://www.powerelectronicsnews.com/silicon-carbide-sic-ena...
- idiotsecant 1y ago
  Let's talk about how you think inverters do frequency support without storage, which was the central point of my post.

toast0 1y ago

> "AEMO identified software settings in the wind farms that prevented repeated restarts once voltage or frequency events occurred too often. " > Grid operators are currently mostly against renewable and so they impose "blunt" disconnect rules on inverters behind renewable sources, and this comes to bite the grid when the proverbial shit hits the fan. As a distributed systems person, this seems like a coordination/communication problem. If a single node is having repeated events, it may likely be broken and staying offline could be a better choice. If multiple nodes are having repeated events, maybe it's better for them to stay connection and do their best.