Spec update

[seanmcilroy29]

Proposed Spec update

[mrchrisadams]

hi @seanmcilroy29 - I appreciate I missed this on the last call, that new levels of conformance had been introduced to this - both A1. (mandatory) and A2. (optional).

Was this what came out of the conversation in #109 when speaking to folks at the ISO? I'm asking in the context of people who might build tooling for future validation against different levels of conformancy.

[mrchrisadams]

@seanmcilroy29 - can I check I understand here? I'm having a bit of trouble parsing annual average location-based marginal grid-carbon-intensity .

I understand the following term:

1. annual average location-based grid-carbon-intensity - for this, I understand it to be the mean of all 8760 hourly carbon intensity figures over the year. And for hourly carbon intensity, I understand to be a weighted average of the different forms of generation used (so if there was were two units of coal, and one of gas you would use one unit for gas, plus two units for coal).

This is available as open data at a country level from various government bodies, but also groups like Ember, amnd Our World In Data, and at higher geographic and temporal resolution from groups like Electricity Maps.

2. annual average location-based marginal grid-carbon-intensity - for this, I am less clear about what this refers to, and who the providers are. I know Watttime is a provider of marginal carbon intensity figures, but as I understand it the mechanism used to work out marginal intensity differs from provider to provider, so there is much less fungibility.

In the SCI, there is a term called Region specific carbon intensity, which has been used to avoid needing to be prescriptive about which one to use for SCI calculation.

If we want to be consistent with the SCI, it seems like annual average region specific carbon intensity would cover both cases without being too prescriptive. Is there a reason we can't use that? We have columns for both kinds of grid carbon intensity in the schema.

The annual average location-based marginal grid-carbon-intensity