8.3.2. Commodity Price Projections

This file can be used to supply pre-set prices for commodities. The interpretation of these prices depends on the type of commodity:

• For non-enviromental commodities (energy, service, material), prices represent the monetary cost of purchasing the commodity. Whether a price projection is required or not depends on the processes in the model and the simulation settings:

  • For commodities that are produced by processes in the model, the behaviour depends on the simulation mode:

    • In equilibrium mode (maximum_iterations > 1), price projections are optional. If not provided, prices are initialised to zero for all years. Once the commodity is produced, its price is calculated endogenously for that year and carried forward to subsequent years until updated again. Until the first time a commodity is produced, the price remains at the projected value (or zero if no projection is provided). Note: because prices are updated during intermediate iterations, a commodity may retain a previously calculated price even if it is not produced in the final converged solution.

    • Outside equilibrium mode (maximum_iterations = 1), prices are not calculated endogenously, so projections are required for all years. Any missing values will be interpreted as zero (i.e. no cost to purchase).

  • For commodities that are not produced by processes in the model, and are not free, prices should be provided for all years as they cannot be endogenously calculated. Lack of a price trajectory will be interpreted as a price of 0 for all periods (i.e. no cost to purchase).

• For environmental commodities, prices represent levies on production (e.g. carbon tax). In most cases, these will not be calculated endogenously, so users should provide full price trajectories. The exception is when using the carbon budget mode, where the prices of environmental commodities may be updated throughout the simulation. Lack of a price trajectory will be interpreted as a price of 0 for all periods (i.e. no levy on production), again with the exception of the carbon budget mode.

Price trajectories should be stored in a CSV file with the structure shown in the table below, and referenced from the TOML settings file using the projections key.

Initial market projections

region	attribute	year	com1	com2	com3
region1	CommodityPrice	2010	20	1.9583	2
region1	CommodityPrice	2015	20	1.9583	2
region1	CommodityPrice	2020	20.38518042	1.996014941	2.038518042
region1	CommodityPrice	2025	20.77777903	2.034456234	2.077777903
region1	CommodityPrice	2030	21.17793872	2.073637869	2.117793872
region1	CommodityPrice	2035	21.58580508	2.113574105	2.158580508
region1	CommodityPrice	2040	22.00152655	2.154279472	2.200152655
region1	CommodityPrice	2045	22.42525441	2.195768786	2.242525441
region1	CommodityPrice	2050	22.85714286	2.238057143	2.285714286

region

represents the region ID and needs to be consistent across all the data inputs

attribute

defines the attribute type. In this case it refers to the CommodityPrice; it is relevant only for internal use

year

corresponds to the time periods of the simulation; the simulated time framework in the example goes from 2010 through to 2050 with a 5-year time step

Commodities (one column per commodity)

Any further columns represent the commodities modelled, with names matching those defined in the global commodities file. Values in these columns represent the price of the commodity in the given year/region.

Note: All commodity prices should be expressed in the currency specified in the settings file. For example, if the currency is set to “USD” and a commodity has units “PJ”, then the prices for that commodity should be expressed as “USD/PJ”.