[sgtnoodle]

One could power the equipment off the turbine when it's operating, and off an alternative supply otherwise.

It seems a little silly to worry about where the specific electrons came from to power the equipment, though. If powering that equipment enables a wind turbine to produce more power than it would have without that equipment, then it seems like the existence of that equipment is "green" whether or not its power came from dirtier sources.

[mike_d]

Wind turbines generate 690v three phase. It isn't stepped down until it gets to a substation near the consumer.

The power needed onsite (lights, control systems, energy to start the blades spinning, etc) usually comes from a natural gas generator or a direct feed from a fossil fuel plant if one is nearby. Due to circular dependencies, you can't power them off the energy they generate.

[KennyBlanken]

> Wind turbines generate 690v three phase. It isn't stepped down until it gets to a substation near the consumer.

Large utility-scale wind turbines do not have power leaving them at 690V. It's many kilovolts. If they put out 690V, just for the sake of example a 2MW turbine would be generating ~3,000A.

> The power needed onsite (lights, control systems, energy to start the blades spinning, etc)

Self-motoring is only necessary on stall-regulated turbines. Most large utility-scale turbines are pitch-regulated.

Here's video of a turbine starting up, showing its control panel with power in/out indicated:

https://www.youtube.com/watch?v=3bYZ14eebFw

> usually comes from a natural gas generator or a direct feed from a fossil fuel plant if one is nearby

That is not how electrical grids work.

If a wind generator is not generating power and goes online, the power for its control systems comes from the grid, which encompasses all the electrical generation devices attached to said grid. Power for control systems could be coming from other wind turbines, solar, hydro, stored energy, nuclear, whatever.

> Due to circular dependencies, you can't power them off the energy they generate.

If the generators are connected to the grid and generating power, all the control systems, lighting, whatever - is connected to the same grid. If it's not generating power, all those systems are still connected to the grid.

[sgtnoodle]

I don't know anything about the domain, but I'm pretty sure it wouldn't be a big deal to tap off a few kilowatts or so using a secondary winding. Something similar to the alternator on a car perhaps. It doesn't need to be the same circuit and efficiency as the main power generation path.

What do you mean circular dependencies? You mean that you need an independent source of power for all the infrastructure to turn the turbines on when they're not currently generating? Sure, that makes sense. It seems like there's a ton of ways to implement that. Grid power, generators, batteries and solar panels, etc.