Improve gross to net generation regression about open-grid-emissions HOT 1 OPEN

Currently, these regression values are not currently used in the data pipeline, although the linear model seems to fit the data well (r2-adj > 0.9). See this documentation for background on this method. This is because:

• the calculated net generation, when summed to the annual level, will not exactly match the total volume of net generation reported in EIA-923.
• For some (sub)plants the intercept term is positive, which does not have an intuitive physical explanation (it would mean that a plant could have positive net generation even when gross generation is zero).

Here, it seems like the tradeoff is between a) ensuring that the total net generation exactly matches the reported total net generation, or b) ensuring that the hourly profile has a shape that is as realistic as possible.

from open-grid-emissions.