[geerlingguy]

Could they also use power grid sync? Not sure as I haven't talked to anyone in wind power, but grid sync would be pretty close to 1 Hz at least in the US.

Building a product that would sync at 1 Hz via GPS that works in the US and other countries with 50 Hz power would be a little easier than syncing to grid phase though.

[estimator7292]

You can have each tower derive a perfectly stable 1Hz signal from the mains, but you have no way to synchronize those signals. Each tower's 'tick' starts at a random point in the 60Hz cycle.

You need an external, dedicated channel for this. You either synchronize with signals sent between towers or with a global signal from somewhere else (space). GPS broadcasts atomic time references for free, so everyone just uses that

[mjevans]

Just like a freeway, public good and public benefit are things government should be doing well. (We the people, for us the people)

[scblock]

Definitely GPS. Other methods have been used in the past--I remember reading operating reports from a wind farm nearly 20 years ago that slowly brought all its lights in line with each other over several months--but these days you can buy mainstream lighting with the GNSS receiver built in from a number of suppliers. They make it easy.

For wind farm use most also have an external input for ADLS triggers, though that usually also requires a separate controller and communications connection to manage the ADLS signals.

The flashing red lights are L-864 type. The requirements are 20 to 40 flashes per minute (FPM), and typically 30 FPM is used.

[geerlingguy]

Hmm... maybe I could build a 1pps GPSDO based on light flashes from nearby towers, then. No need for my own GPS antenna!

[mjevans]

You'd probably have better timekeeping from a reasonably connected Pi with a common NTP daemon (take your pick, some are easier to configure / query), and a realtime-ish thread to emit your PPS signal on a GPIO or similar.

Probably more robust than line of sight, and able to pool with other NTP servers in your home-lab (and beyond).

[geerlingguy]

True, but I'm not thinking of a practical method, just fun. I already have GPS derived time here, but that's been reliable and boring!