Handling foreign BAs in the consumed emissions calculation

[grgmiller]

When calculating consumed emissions for BAs that import electricity from foreign balancing authorities in Canada or Mexico, we need to know the interchange volume with the foreign BA and the generated emissions intensity of any imported electricity. However, generation data is not reported in EIA-930 for these foreign BAs, so we do not have insight into the emissions intensity of electricity imported from these regions.

For now, our method makes several simplifying assumptions that are used in the gridemissions code, although these have some drawbacks:

• We assume that total generation from these foreign regions is equal to exports.
• We assume that the fuel type of this generation is "OTH" unless the region is BCHA, HQT, or MHEB (hydro-heavy/only regions), in which case we assume that the fuel type is hydro for all regions
• We assign an emission factor to OTH fuel based on the (U.S.) national-average annual-average generated emission factor for all fuels

There are several options for how we can fix this:

• separately scrape generation mix data from each of these foreign BAs (might not be available for each BA)
• Manually research reported fuel mix data (at the annual level) for each of these BAs so that we can estimate emissions factors for all pollutants
• Use reported emission factors from these BAs (although usually only available for CO2).
• As an alternative to assuming the U.S. national/annual average emission rate, we could set the emission rate equal to the importing region's generated emission rate, so that the imported emissions neither increase nor decrease the region's emissions.