Gas Storage

Graph structure

A storage for a gas commodity is represented in Macro using the following graph structure:

%%{init: { 'theme': 'base', "themeCSS": ".node circle { radius: 40 !important; }", 'themeVariables': { 'background': '#D1EBDE' } }}%% flowchart LR subgraph GasStorage direction BT B((Gas)) --Charge--> A{{..}} A --Discharge--> B C((Electricity)) --Charge--> A C --Discharge--> A A --Charge--> D[Storage] D --Discharge--> A end legend@{img: "../../images/battery.png", w: 120, h: 100, constraint: "off"} GasStorage ~~~ legend style A fill:black,stroke:black,color:black; style B r:40,fill:lightblue,stroke:black,color:black,stroke-dasharray: 3,5; style C r:40,fill:orange,stroke:black,color:black,font-size: 12, stroke-dasharray: 3,5; style D fill:lightblue,stroke:black,color:black, font-size: 12; linkStyle 0,1 stroke:lightblue, stroke-width: 3px; linkStyle 2,3 stroke:orange, stroke-width: 3px; linkStyle 4,5 stroke:lightblue, stroke-width: 3px; style legend fill:white

%%{init: { 'theme': 'base', "themeCSS": ".node circle { r: 100 !important; }", 'themeVariables': { 'background': '#D1EBDE' } }}%% flowchart LR subgraph GasPipeline direction BT B((Gas)) --Charge--> A{{..}} A --Discharge--> E((Gas)) C((Electricity)) --Charge--> A F((Electricity)) --Discharge--> A A --Charge--> D[Storage] D --Discharge--> A subgraph "Source location" B ~~~ C end subgraph "Dest location" E ~~~ F end end legend@{img: "../../images/battery.png", w: 120, h: 100, constraint: "off"} GasPipeline ~~~ legend style A fill:black,stroke:black,color:black; style B radius:50,fill:lightblue,stroke:black,color:black,font-size: 12, stroke-dasharray: 3,5; style C r:40,fill:orange,stroke:black,color:black,font-size: 12, stroke-dasharray: 3,5; style D r:40,fill:lightblue,stroke:black,color:black, font-size: 12; style E r:40,fill:lightblue,stroke:black,color:black, font-size: 12,stroke-dasharray: 3,5; style F r:40,fill:orange,stroke:black,color:black, font-size: 12,stroke-dasharray: 3,5; linkStyle 0,1 stroke:lightblue, stroke-width: 3px; linkStyle 2,3 stroke:orange, stroke-width: 3px; linkStyle 4,5 stroke:lightblue, stroke-width: 3px; style legend fill:white

A gas storage asset is made of:

1 Storage component, representing the gas storage process. The gas type is set using the commodity attribute (see table below).
1 Transformation component, representing the gas compressor.
4 Edge components:
- 1 incoming Electricity Edge, representing the electricity consumption for powering the compressor.
- 1 incoming Gas Edge, representing the gas flow into the storage asset through the compressor.
- 1 internal Gas Edge, representing the gas flow between the compressor and the storage. This can be seen as a charge edge for the storage component.
- 1 outgoing Gas Edge, representing the discharged edge of the gas storage.

Attributes

The structure of the input file for a gas storage asset follows the graph representation. Each global_data and instance_data will look like this:

{
    "transforms":{
        // ... transformation-specific attributes ...
    },
    "edges":{
        "compressor_elec_edge": {
            // ... compressor_elec_edge-specific attributes ...
        },
        "compressor_gas_edge": {
            // ... compressor_gas_edge-specific attributes ...
        },
        "charge_edge": {
            // ... storage_gas_edge-specific attributes ...
        },
        "discharge_edge": {
            // ... discharge_gas_edge-specific attributes ...
        }
    },
    "storage":{
        // ... storage-specific attributes ...
    }
}

Transformation

The definition of the transformation object can be found here MacroEnergy.Transformation.

Attribute	Type	Values	Default	Description
timedata	`String`	`String`	Required	Time resolution for the time series data linked to the transformation. E.g. "Hydrogen".
constraints	`Dict{String,Bool}`	Any Macro constraint type for vertices	`BalanceConstraint`	List of constraints applied to the transformation. E.g. `{"BalanceConstraint": true}`.
electricity_consumption $\epsilon_{elec\_consumption}$	`Float64`	`Float64`	`0.0`	$MWh_{elec}/MWh_{gas}$

Flow equations

In the following equations, $\phi$ is the flow of the commodity and $\epsilon$ is the stoichiometric coefficient defined in the transformation table below.

GasStorage

Note: c is the type of the commodity being stored. The following equation is related to the compressor.

\[\begin{aligned} \phi_{elec} &= \phi_{c} \cdot \epsilon_{elec\_consumption} \\ \end{aligned}\]

Look also at the "Efficiency" tip below for more information on the efficiency of charging/discharging process.

Edges

All the edges are represented by the same set of attributes. The definition of the Edge object can be found here MacroEnergy.Edge.

Attribute	Type	Values	Default	Description
type	`String`	Any Macro commodity type matching the commodity of the edge	Required	Commodity of the edge. E.g. "Electricity".
start_vertex	`String`	Any node id present in the system matching the commodity of the edge	Required	ID of the starting vertex of the edge. The node must be present in the `nodes.json` file. E.g. "elec_node_1".
end_vertex	`String`	Any node id present in the system matching the commodity of the edge	Required	ID of the ending vertex of the edge. The node must be present in the `nodes.json` file. E.g. "elec_node_2".
constraints	`Dict{String,Bool}`	Any Macro constraint type for Edges	Check box below	List of constraints applied to the edge. E.g. `{"CapacityConstraint": true}`.
availability	`Dict`	Availability file path and header	Empty	Path to the availability file and column name for the availability time series to link to the edge. E.g. `{"timeseries": {"path": "assets/availability.csv", "header": "SE_Above_ground_storage"}}`.
can_expand	`Bool`	`Bool`	`false`	Whether the edge is eligible for capacity expansion.
can_retire	`Bool`	`Bool`	`false`	Whether the edge is eligible for capacity retirement.
capacity_size	`Float64`	`Float64`	`1.0`	Size of the edge capacity.
efficiency	`Float64`	Number $\in$ [0,1]	`1.0`	Efficiency of the charging/discharging process.
existing_capacity	`Float64`	`Float64`	`0.0`	Existing capacity of the edge in MW.
fixed_om_cost	`Float64`	`Float64`	`0.0`	Fixed operations and maintenance cost (USD/MW-year).
has_capacity	`Bool`	`Bool`	`false`	Whether capacity variables are created for the edge.
integer_decisions	`Bool`	`Bool`	`false`	Whether capacity variables are integers.
investment_cost	`Float64`	`Float64`	`0.0`	Annualized capacity investment cost (USD/MW-year)
loss_fraction	`Float64`	Number $\in$ [0,1]	`0.0`	Fraction of transmission loss.
max_capacity	`Float64`	`Float64`	`Inf`	Maximum allowed capacity of the edge (MW). Note: add the `MaxCapacityConstraint` to the constraints dictionary to activate this constraint.
min_capacity	`Float64`	`Float64`	`0.0`	Minimum allowed capacity of the edge (MW). Note: add the `MinCapacityConstraint` to the constraints dictionary to activate this constraint.
min_flow_fraction	`Float64`	Number $\in$ [0,1]	`0.0`	Minimum flow of the edge as a fraction of the total capacity. Note: add the `MinFlowConstraint` to the constraints dictionary to activate this constraint.
ramp_down_fraction	`Float64`	Number $\in$ [0,1]	`1.0`	Maximum decrease in flow between two time steps, reported as a fraction of the capacity. Note: add the `RampingLimitConstraint` to the constraints dictionary to activate this constraint.
ramp_up_fraction	`Float64`	Number $\in$ [0,1]	`1.0`	Maximum increase in flow between two time steps, reported as a fraction of the capacity. Note: add the `RampingLimitConstraint` to the constraints dictionary to activate this constraint.
variable_om_cost	`Float64`	`Float64`	`0.0`	Variable operation and maintenance cost (USD/MWh).

Efficiency

The efficiency of the charging/discharging process can be set in the charge_edge and discharge_edge parts of the input file. These parameters are used, for example, in the Balance constraint to balance the charge and discharge flows.

Default constraints

The only default constraint for the edges of the gas storage asset is the Capacity constraint applied to both the charge and discharge edges.

Storage component

The definition of the Storage object can be found here MacroEnergy.Storage.

Attribute	Type	Values	Default	Description
commodity	`String`	Any Macro commodity type	Required	Commodity being stored. E.g. "Hydrogen".
constraints	`Dict{String,Bool}`	Any Macro constraint type for storage	`BalanceConstraint`, `StorageCapacityConstraint`	List of constraints applied to the storage. E.g. `{"BalanceConstraint": true}`.
can_expand	`Bool`	`Bool`	`false`	Whether the storage is eligible for capacity expansion.
can_retire	`Bool`	`Bool`	`false`	Whether the storage is eligible for capacity retirement.
charge_discharge_ratio	`Float64`	`Float64`	`1.0`	Ratio between charging and discharging rates.
existing_capacity_storage	`Float64`	`Float64`	`0.0`	Initial installed storage capacity (MWh).
fixed_om_cost_storage	`Float64`	`Float64`	`0.0`	Fixed operations and maintenance cost (USD/MWh-year).
investment_cost_storage	`Float64`	`Float64`	`0.0`	Annualized investment cost of the energy capacity for a storage technology (USD/MWh-year).
long_duration	`Bool`	`Bool`	`false`	Whether the storage is a long-duration storage. Note: if `true`, the long-duration storage constraint will be applied.
max_capacity_storage	`Float64`	`Float64`	`Inf`	Maximum allowed storage capacity (MWh).
max_duration	`Float64`	`Float64`	`0.0`	Maximum ratio of installed energy to discharged capacity that can be installed (hours).
min_capacity_storage	`Float64`	`Float64`	`0.0`	Minimum allowed storage capacity (MWh).
min_duration	`Float64`	`Float64`	`0.0`	Minimum ratio of installed energy to discharged capacity that can be installed (hours).
min_outflow_fraction	`Float64`	`Float64`	`0.0`	Minimum outflow as a fraction of capacity.
min_storage_level	`Float64`	`Float64`	`0.0`	Minimum storage level as a fraction of capacity.
max_storage_level	`Float64`	`Float64`	`1.0`	Maximum storage level as a fraction of capacity.
storage_loss_fraction	`Float64`	Number $\in$ [0,1]	`0.0`	Fraction of stored commodity lost per timestep.

Default constraints

As noted in the above table, the default constraints for the storage component of the gas storage are the following:

If the storage is a long-duration storage, the following additional constraints are applied:

Long-duration storage constraints

Example

The following input file example shows how to create a hydrogen storage asset in each of the three zones SE, MIDAT and NE.

{
    "h2stor": [
        {
            "type": "GasStorage",
            "global_data": {
                "nodes": {},
                "transforms": {
                    "timedata": "Hydrogen",
                    "constraints": {
                        "BalanceConstraint": true
                    }
                },
                "edges": {
                    "discharge_edge": {
                        "type": "Hydrogen",
                        "unidirectional": true,
                        "can_expand": true,
                        "can_retire": false,
                        "has_capacity": true,
                        "constraints": {
                            "CapacityConstraint": true,
                            "RampingLimitConstraint": true
                        }
                    },
                    "charge_edge": {
                        "type": "Hydrogen",
                        "unidirectional": true,
                        "has_capacity": true,
                        "can_expand": true,
                        "can_retire": false,
                        "constraints": {
                            "CapacityConstraint": true
                        }
                    },
                    "compressor_elec_edge": {
                        "type": "Electricity",
                        "unidirectional": true,
                        "has_capacity": false
                    },
                    "compressor_gas_edge": {
                        "type": "Hydrogen",
                        "unidirectional": true,
                        "has_capacity": false
                    }
                },
                "storage": {
                    "commodity": "Hydrogen",
                    "can_expand": true,
                    "can_retire": false,
                    "constraints": {
                        "StorageCapacityConstraint": true,
                        "BalanceConstraint": true,
                        "MinStorageLevelConstraint": true
                    }
                }
            },
            "instance_data": [
                {
                    "id": "SE_Above_ground_storage",
                    "transforms": {
                        "electricity_consumption": 0.018029457
                    },
                    "edges": {
                        "discharge_edge": {
                            "end_vertex": "h2_SE",
                            "existing_capacity": 0,
                            "investment_cost": 0.0,
                            "fixed_om_cost": 0.0,
                            "variable_om_cost": 0.0,
                            "efficiency": 1.0,
                            "ramp_up_fraction": 1,
                            "ramp_down_fraction": 1
                        },
                        "charge_edge": {
                            "existing_capacity": 0,
                            "investment_cost": 3219.236569,
                            "fixed_om_cost": 0.0,
                            "variable_om_cost": 0.0,
                            "efficiency": 1.0
                        },
                        "compressor_gas_edge": {
                            "start_vertex": "h2_SE"
                        },
                        "compressor_elec_edge": {
                            "start_vertex": "elec_SE"
                        }
                    },
                    "storage": {
                        "investment_cost_storage": 873.013307,
                        "fixed_om_cost_storage": 28.75810056,
                        "storage_loss_fraction": 0.0,
                        "min_storage_level": 0.3
                    }
                },
                {
                    "id": "MIDAT_Above_ground_storage",
                    "transforms": {
                        "electricity_consumption": 0.018029457
                    },
                    "edges": {
                        "discharge_edge": {
                            "end_vertex": "h2_MIDAT",
                            "existing_capacity": 0,
                            "investment_cost": 0.0,
                            "fixed_om_cost": 0.0,
                            "variable_om_cost": 0.0,
                            "efficiency": 1.0,
                            "ramp_up_fraction": 1,
                            "ramp_down_fraction": 1
                        },
                        "charge_edge": {
                            "existing_capacity": 0,
                            "investment_cost": 3219.236569,
                            "fixed_om_cost": 0.0,
                            "variable_om_cost": 0.0,
                            "efficiency": 1.0
                        },
                        "compressor_gas_edge": {
                            "start_vertex": "h2_MIDAT"
                        },
                        "compressor_elec_edge": {
                            "start_vertex": "elec_MIDAT"
                        }
                    },
                    "storage": {
                        "investment_cost_storage": 873.013307,
                        "fixed_om_cost_storage": 28.75810056,
                        "storage_loss_fraction": 0.0,
                        "min_storage_level": 0.3
                    }
                },
                {
                    "id": "NE_Above_ground_storage",
                    "transforms": {
                        "electricity_consumption": 0.018029457
                    },
                    "edges": {
                        "discharge_edge": {
                            "end_vertex": "h2_NE",
                            "existing_capacity": 0,
                            "investment_cost": 0.0,
                            "fixed_om_cost": 0.0,
                            "variable_om_cost": 0.0,
                            "efficiency": 1.0,
                            "ramp_up_fraction": 1,
                            "ramp_down_fraction": 1
                        },
                        "charge_edge": {
                            "existing_capacity": 0,
                            "investment_cost": 3219.236569,
                            "fixed_om_cost": 0.0,
                            "variable_om_cost": 0.0,
                            "efficiency": 1.0
                        },
                        "compressor_gas_edge": {
                            "start_vertex": "h2_NE"
                        },
                        "compressor_elec_edge": {
                            "start_vertex": "elec_NE"
                        }
                    },
                    "storage": {
                        "investment_cost_storage": 873.013307,
                        "fixed_om_cost_storage": 28.75810056,
                        "storage_loss_fraction": 0.0,
                        "min_storage_level": 0.3
                    }
                }
            ]
        }
    ]
}