What are the *_id_pudl fields for?

[JesseWeinstein]

[JesseWeinstein]

@bendnorman answered (on the OpenStreetMapUS Slack, where I originally asked this):

The *_id_pudl fields connect the EIA and FERC data. EIA and FERC do not share common keys for plants and utilities so each year we create PUDL ids for new utilities and plants and map the *_id_eia to the *_id_ferc.

[zaneselvans]

There is also unit_id_pudl which is a generation unit ID that we've assigned -- basically any ID that we're assigning to structure the data, which is not coming from some external source we've tried to suffix with _id_pudl so others know it's specific to our DB.