Writing gqueries

Gqueries are in fact stored GQL (Graph Query Languague) procedures that have a key. If a user for example wants to know the total CO₂ emissions of an area, they can request ETEngine for the gquery total_co2_emissions and do not have to worry about the underlying intricacies. An overview of all gqueries can be found in this folder.

Guidelines

An overview of available GQL functions can be found in the GQL section.
Base gqueries are added in the general folder on Github.
Other gqueries, for example gqueries used in output_elements, should refer to base gqueries when possible.
Base gqueries have a consistent set of base units, for example kg for emissions, MW for capacity and MJ for energy.
Base gqueries have a consistent nomenclature: for example type, subtype, sector, subsector, carrier.
Base gqueries should have a description.
To enhance readability, the preferred indentation style for gqueries is first to indent with 4 spaces, followed by an additional 2 spaces for each subsequent level (see the example below).

Example for final_demand_energetic_industry_steel_wood_pellets:

# Energetic final demand of the 'coal' carrier group in industry steel sector.

- query =
    SUM(
      V(
        FILTER(
          FILTER(
            INTERSECTION(EG(final_demand),EG(appliances_households)
            ),
            "coal? || coal_gas? || cokes? || lignite?"
          ),
          "energetic?"
        ),
        value
      )
    )
- unit = PJ

Guidelines​

Guidelines