Comment by toomuchtodo

Ting by Whisker Labs [1] in the US has this data aggregated by their home electrical safety monitoring devices, and there’s GridRadar [2] in Europe. As you mention, its GNSS based time sync with something a little less featured than PMUs [3] (phasor measurement units) traditionally used for grid health monitoring.

[1] https://power-quality.tingfire.com/

[2] https://gridradar.net/en/wide-area-monitoring-system

[3] https://en.wikipedia.org/wiki/Phasor_measurement_unit