Store IEA energy balance info in structure files

[khaeru]

We use various files like commodity.yaml, node/R12.yaml, to store code lists: these are lists of codes with an identifier R12_AFR, name, description, and 0 or more annotations. For instance:

message-ix-models/message_ix_models/data/commodity.yaml

Lines 6 to 14 in c9f1638

	coal:
	name: Coal
	units: GWa
	report: Solids|Fossil
	# NB same value as "Coking coal"; this choice is arbitrary
	# NB in message_doc, this appears as "Hard coal", but this
	# term usually refers to anthracite, which has a higher
	# carbon emission factor.
	ipcc-1996-name: "Other Bituminous Coal"

These annotations carry precise information about each code that can be directly usable in preparing model structure and data. In this case, the ipcc-1996-name: annotation gives the exact name that appears in a particular data source. This is a simple, clear, and unambiguous statement that a certain external name/code/ID should be used in correspondence with c=coal.

In particular, the IEA (extended) energy balances have particular code lists for concepts named FLOW and PRODUCT; these are dimensions in the data.

To do:

• Establish an ID and form for annotations that give correspondence between MESSAGEix-GLOBIOM codes and those appearing in IEA (E)EB. For instance, something like:

  solar_pv_ppl:
    name: solar_pv_ppl
    description: Solar photovoltaic power plant (no storage)
    # ...
    iea-eb:
    - {PRODUCT: elect.output in gwh, FLOW: solar PV}

• Update the existing code lists with these annotations.

• Provide or extend tools that read this structural information from the code lists and prepare Python data structures that are needed for other operations; in particular for converting the IEA (E)WEB data to form(s) needed by MESSAGEix-GLOBIOM.

• Provide or extend tools for writing these structures out for convenience/reference, for instance in a form similar to the “Excel mapping files” that are sometimes used.

cf. iiasa/message_data#505

[khaeru]

This was partly addressed in #75; see for instance:

message-ix-models/message_ix_models/data/commodity.yaml

Lines 57 to 61 in a777cda

	ethanol:
	name: Ethanol
	units: GWa
	report: Liquids|Biomass
	iea-eweb-product: [BIODIESEL, BIOGASOL, BIOJETKERO, OBIOLIQ]