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When lightning strikes: managing impacts on wind turbines

35 points by zeristor 5y ago

zeristor 5y ago
Wind Turbines induce lightning… There is a potential difference over that height. Lightning strikes are quite overwhelming, but perhaps additional power could be gleaned from diffusing the pd across that height. “Two types of lightning can occur, he says: one that starts in a thunderstorm and then propagates downwards, attaching to the turbine tip – called downward initiated lightning – and another, ‘upward lighting’, that happens when the turbine gets very tall and itself starts to generate lightning that wouldn’t otherwise occur.” It would be interesting to see pictures and videos of lightning strikes.
- Animats 5y ago
  It would be interesting to see pictures and videos of lightning strikes. There are plenty of such pictures. There's a big collection of lightning strike pictures for the Empire State Building, which has been used for lightning studies since 1935. It gets hit about 25 times a year. The headache for wind turbines is carbon fiber. Fiberglas blades are good insulators. Aluminum blades are good conductors. But carbon fiber blades are resistors, so they can be heated and burnt by lightning. This is also a headache with aircraft using carbon fiber. In both cases, metal has to be embedded to provide a conductive path.
  - xyzzy21 5y ago
    This is the same feature that increases lightning damage on composite body aircraft. Additional metal (weight) has to be added to shield and conduct lightning away from sensitive electronics.
sambeau 5y ago
God I hate websites that mess with the back-button. This site adds an extra copy of itself to the history every time you try to go back. It's such a rude, ugly thing to do and the practice appears to be spreading.
londons_explore 5y ago
How much energy is in a lightning strike? How much can be collected and put into the electrical grid? It becomes the age old problem of storage of electricity, but perhaps by firing a wire into clouds every few seconds, we can make mini-strikes that happen every few seconds, and then the storage problem might be solved with a capacitor and inductor bank.
- jonsen 5y ago
  https://physics.stackexchange.com/questions/19082/how-much-energy-is-in-a-lightning-strike https://physics.stackexchange.com/questions/19082/how-much-e...
- zaarn 5y ago
  A lightning may contain between 200 and 2000 kWh of energy. There isn't any capacitor or inductor bank that large that could contain this amount of energy that fast. The additional trouble would then be making this energy useful, as capturing this amount of energy safely is not trivial. On top of that, an individual wind turbine is unlikely to be struck often enough to actually make up for the investment of a potential capacitor bank that large.
  - JohnJamesRambo 5y ago
    I’m curious how long it takes a spinning big wind turbine to make 200-2000 kWh of energy? This would properly frame how much energy is in a lightning strike for me.
    - mkj 5y ago
      If it's a 12MW turbine it's 10 minutes for 2000kWh. So actually probably not worth bothering with the lightning capture. I'd always thought lighting strikes were more energetic than that.
      - zaarn 5y ago
        What makes lightning strikes so powerful is less the total energy and more the short timeframe it's delivered in.
LWIRVoltage 5y ago
Since wind turbine fields presumably are going to get bigger and bigger, why not take advantage and use the opportunity to deploy lightning harvesting equipment? After all, prior attempts showed that the only limiting factor that needed to be addressed was scale, and it'd work. .. https://en.m.wikipedia.org/wiki/Harvesting_lightning_energy https://en.m.wikipedia.org/wiki/Harvesting_lightning_energy I will note that it takes finesse, as one will notice from watching other attempts to lightning. .. whenther its universities or. ..not-smart people on YouTube trying to do it, the electrical situation needs to be optimal. .. and it helps if you directly charge a potential at your target area, in order to get good odds... Otherwise, launching rockets with wire into thunderheads is not a gaurantee you will get a strike, as you might accidentally just bleed away the electrical potential, lightning rod style
- jacksonkmarley 5y ago
  As the wikipedia article notes, you don't get much energy from lightning because it's such a short duration. Interesting for research though.
wingineer 5y ago
Great article. Lightning concerns are affecting wind turbines design choices in many ways nowadays. I know several OEMs use fiber-optic cables to connect to load sensors within blades to prevent lightning damage.

35 points by zeristor 5y ago

Wind Turbines induce lightning… There is a potential difference over that height. Lightning strikes are quite overwhelming, but perhaps additional power could be gleaned from diffusing the pd across that height. “Two types of lightning can occur, he says: one that starts in a thunderstorm and then propagates downwards, attaching to the turbine tip – called downward initiated lightning – and another, ‘upward lighting’, that happens when the turbine gets very tall and itself starts to generate lightning that wouldn’t otherwise occur.” It would be interesting to see pictures and videos of lightning strikes.

Animats 5y ago
It would be interesting to see pictures and videos of lightning strikes. There are plenty of such pictures. There's a big collection of lightning strike pictures for the Empire State Building, which has been used for lightning studies since 1935. It gets hit about 25 times a year. The headache for wind turbines is carbon fiber. Fiberglas blades are good insulators. Aluminum blades are good conductors. But carbon fiber blades are resistors, so they can be heated and burnt by lightning. This is also a headache with aircraft using carbon fiber. In both cases, metal has to be embedded to provide a conductive path.
- xyzzy21 5y ago
  This is the same feature that increases lightning damage on composite body aircraft. Additional metal (weight) has to be added to shield and conduct lightning away from sensitive electronics.

sambeau 5y ago

God I hate websites that mess with the back-button. This site adds an extra copy of itself to the history every time you try to go back. It's such a rude, ugly thing to do and the practice appears to be spreading.

londons_explore 5y ago

How much energy is in a lightning strike? How much can be collected and put into the electrical grid? It becomes the age old problem of storage of electricity, but perhaps by firing a wire into clouds every few seconds, we can make mini-strikes that happen every few seconds, and then the storage problem might be solved with a capacitor and inductor bank.

jonsen 5y ago
https://physics.stackexchange.com/questions/19082/how-much-energy-is-in-a-lightning-strike https://physics.stackexchange.com/questions/19082/how-much-e...
zaarn 5y ago
A lightning may contain between 200 and 2000 kWh of energy. There isn't any capacitor or inductor bank that large that could contain this amount of energy that fast. The additional trouble would then be making this energy useful, as capturing this amount of energy safely is not trivial. On top of that, an individual wind turbine is unlikely to be struck often enough to actually make up for the investment of a potential capacitor bank that large.
- JohnJamesRambo 5y ago
  I’m curious how long it takes a spinning big wind turbine to make 200-2000 kWh of energy? This would properly frame how much energy is in a lightning strike for me.
  - mkj 5y ago
    If it's a 12MW turbine it's 10 minutes for 2000kWh. So actually probably not worth bothering with the lightning capture. I'd always thought lighting strikes were more energetic than that.
    - zaarn 5y ago
      What makes lightning strikes so powerful is less the total energy and more the short timeframe it's delivered in.

LWIRVoltage 5y ago

Since wind turbine fields presumably are going to get bigger and bigger, why not take advantage and use the opportunity to deploy lightning harvesting equipment? After all, prior attempts showed that the only limiting factor that needed to be addressed was scale, and it'd work. .. https://en.m.wikipedia.org/wiki/Harvesting_lightning_energy https://en.m.wikipedia.org/wiki/Harvesting_lightning_energy I will note that it takes finesse, as one will notice from watching other attempts to lightning. .. whenther its universities or. ..not-smart people on YouTube trying to do it, the electrical situation needs to be optimal. .. and it helps if you directly charge a potential at your target area, in order to get good odds... Otherwise, launching rockets with wire into thunderheads is not a gaurantee you will get a strike, as you might accidentally just bleed away the electrical potential, lightning rod style

jacksonkmarley 5y ago
As the wikipedia article notes, you don't get much energy from lightning because it's such a short duration. Interesting for research though.

wingineer 5y ago

Great article. Lightning concerns are affecting wind turbines design choices in many ways nowadays. I know several OEMs use fiber-optic cables to connect to load sensors within blades to prevent lightning damage.