ExtensionData functions

The package provides the wildcard ExtensionData type as outlined in the Extensions to the model section of the philosophy page. ExtensionData can be utilized to extend the functionality of the model through dispatching on its type. The following function is included in all reference create_node functions, except for Storage types

# Iterate through all data and set up the constraints corresponding to the data
for data ∈ node_data(n)
    constraints_ext_data(m, n, 𝒯, 𝒫, modeltype, data)
end

There is always a fallback option if a ExtensionData is specified, but no functions are provided:

constraints_ext_data(m, n::Node, 𝒯, 𝒫, modeltype::EnergyModel, data::ExtensionData) = nothing

Its application is best explained by the implemented functionality for emissions.

Renamed types and functions

We renamed Data to ExtensionData while retaining the original Data type to avoid breaking changes. If you provide new extension data in one of your packages, we recommend that you adjust the subtyping.

We renamed the function constraints_data with constraints_ext_data while keeping the original function and its call within the individual create_node functions.

The legacy functions will be removed in version 0.10.

Emissions data

Emissions data is an application of extensions via the application of the wildcard data field in the nodes. It allows to consider:

no emissions of a node (no EmissionsData type has to be provided),
energy usage related emissions of a node, that is emissions through the utilization of an energy carrier (EmissionsEnergy) given as input,
the combination of process emissions and energy usage related emissions (EmissionsProcess),
CO₂ capture of energy usage related emissions (CaptureEnergyEmissions),
CO₂ capture of process emissions (CaptureProcessEmissions), and
CO₂ capture of both process and energy usage related emissions (CaptureProcessEnergyEmissions).

The individual fields of the different types are described in the Public interface.

The extension is then implemented through the functions

function constraints_ext_data(m, n::Node, 𝒯, 𝒫, modeltype::EnergyModel, data::EmissionsEnergy)
function constraints_ext_data(m, n::Node, 𝒯, 𝒫, modeltype::EnergyModel, data::EmissionsProcess)
function constraints_ext_data(m, n::Node, 𝒯, 𝒫, modeltype::EnergyModel, data::CaptureEnergyEmissions)
function constraints_ext_data(m, n::Node, 𝒯, 𝒫, modeltype::EnergyModel, data::CaptureProcessEmissions)
function constraints_ext_data(m, n::Node, 𝒯, 𝒫, modeltype::EnergyModel, data::CaptureProcessEnergyEmissions)

in the file data_functions.jl. Correspondingly, we require only a single implementation of a Node to investigate multiple different emission scenarios, depending on the chosen EmissionsData. Both EmissionsEnergy and EmissionsProcess can handle input similar to the other EmissionsData types, allowing for a fast switch between individual emission configurations.