Gas storage
-----------

<img src="../../_static/Gasstorage.png" alt="Alt text" width="50" style="float: left; margin-right: 10px;">

**Technology ID: GAS_STORAGE**



**Input energy interface, with default energy:**

 - CONSUMPTION: gas

**Output energy interface, with default energy:**

 - PRODUCTION: gas

**Technology behaviors:**

 - OPTIM_PATHWAY
 - USE_PMAX_IN
 - OPTIM_PMAX
 - DISCHARGE_TIMES
 - GRADIENTS

**Technology parameters:**

| ID | Label | Unit | Behaviors | Description  |
| --- | --- | --- | --- | --- |
| CAPEX_OVERNIGHT | CAPEX Overnight | Euro/MW |  | -Overall capital expenditure (only used for pathway optimization) |
| DEINVEST_COST | Deinvest cost | Euro/MW |  | Deinvest cost (only used for pathway optimization) |
| LIFETIME | Lifetime |  |  | Lifetime of the asset (only used for pathway optimization) |
| YIELD_INVEST | Yield of investment | % |  | Yield associated with investment |
| INSTALL_MAX | Max installation | MW | OPTIM_PATHWAY | Max installation (only used for pathway optimization) |
| DECOMM_MAX | Max decommissioning | MW | OPTIM_PATHWAY | Max decommissioning (only used for pathway optimization) |
| STORAGE_CAPEX_OVERNIGHT | Overnight CAPEX (Storage) | Euro/MW.h/Year |  | Overnight capital expenditure for storage assets |
| CAPEX | CAPEX | Euro/MW/Year |  | Capital expenditure (only used for capacity optimization) |
| FOC | Fixed Operating Costs | Euro/MW/Year |  | Fixed Operating Costs (only used for capacity optimization) |
| PMAX | Pmax | MW | (not OPTIM_PMAX) and (not OPTIM_PATHWAY) | Installed power capacity |
| PMAXMIN | Min Pmax | MW | OPTIM_PMAX or OPTIM_PATHWAY | Installed capacity lower bound for capacity optimization |
| PMAXMAX | Max Pmax | MW | OPTIM_PMAX or OPTIM_PATHWAY | Installed capacity upper bound for capacity optimization |
| AVAILABILITY | Availability | % |  | Available capacity, expressed as a percentage of the installed capacity |
| CONSUMPTION_COST | Consumption cost | Euro/MW.h |  | Consumption cost |
| EXIT_FEE | Fee for gas withdrawal from the internal network | Euro/MW.h |  | Exit fee |
| PRODUCTION_COST | Production cost | Euro/MW.h |  | Production cost (emission cost excluded) |
| ENTRY_FEE | Fee for gas injection on the internal network | Euro/MW.h |  | Entry fee |
| STORAGE_CAPEX | CAPEX (Storage) | Euro/MW.h/Year |  | Capital expenditure for storage assets |
| STORAGE_CAPACITY | Storage capacity | MW.h |  | Storage capacity |
| STORAGE_AVAILABILITY | Storage availability | % |  | Storage availability, expressed as a percentage of the installed storage capacity |
| MIN_STORAGE_LEVEL | Minimal storage level | % |  | Minimum level for storage, expressed as a percentage of the installed storage capacity |
| DISCHARGE_TIME | Discharge time | h |  | Discharge time |
| PMAX_IN | Pmax In | MW | USE_PMAX_IN and (not OPTIM_PMAX) and (not OPTIM_PATHWAY) | Input maximal power |
| AVAILABILITY_IN | Input availability | % |  | Injection capacity availability |
| MIN_INITIAL_STORAGE_LEVEL | Minimal initial storage level | % |  | Minimal initial storage level, expressed as percentage of the storage capacity |
| MAX_INITIAL_STORAGE_LEVEL | Maximal initial storage level | % |  | Maximal initial storage level, expressed as percentage of the storage capacity |
| PMAX_IN_OUT_RATIO | Withdrawal over Injection ratio (for capacity optimization) | % | OPTIM_PMAX or OPTIM_PATHWAY | Injection (to the storage) over Withdrawal (from the storage) ratio (for capacity optimization) |
| EMPTY_STORAGE_RATIO_WITHDRAWAL | Empty storage ratio of available withdrawal capacity | % |  | Share of storage available withdrawal capacity when empty |
| FILLED_STORAGE_RATIO_INJECTION | Filled storage ratio of available injection capacity | % |  | Share of storage available injection capacity when filled |
| INJECTION_INFLEXION_STORAGE_LEVEL | Injection capacity inflexion storage level | % |  | Storage level at which available injection capacity starts to decrease |
| WITHDRAWAL_INFLEXION_STORAGE_LEVEL | Withdrawal capacity inflexion storage level | % |  | Storage level at which available withdrawal capacity reaches 100% |
| GRADIENT_UP | Gradient up | %/min | GRADIENTS | Maximal upward variation, expressed as a percentage of the available capacity per minute |
| GRADIENT_DOWN | Gradient down | %/min | GRADIENTS | Maximal downward variation, expressed as a percentage of the available capacity per minute |
|  |

**Model code:**

``` python
stateON = AssetState('ON')
moduleStock = addDischargeStock(asset, stateON, minStorageLevel=MIN_STORAGE_LEVEL, initialStorageLevel=None, storageAvailability=STORAGE_AVAILABILITY, initialEqualsFinal=True)
variableStorageInjectionCapacity(MODEL, asset, stateON, moduleStock, pmaxInOutRatio = PMAX_IN_OUT_RATIO)
variableStorageWithdrawalCapacity(MODEL, asset, stateON, moduleStock)
addInitialStorageLevelBounds(asset, moduleStock, initialStorageLevel=None, minInitialStorageLevel=MIN_INITIAL_STORAGE_LEVEL, maxInitialStorageLevel= MAX_INITIAL_STORAGE_LEVEL)
   
# Computing overall cost to set on incoming flows (consumption cost + network exit fee)
overallConsumptionCost  = getAssetData(asset, CONSUMPTION_COST, dataName=LABELS[CONSUMPTION_COST], mustExist=False)
exitFee = getAssetData(asset, "EXIT_FEE", mustExist=False)
if exitFee is not None:
	overallConsumptionCost += exitFee
   
# Computing overall cost to set on outcoming flows (production cost + network entry fee)
overallProductionCost  = getAssetData(asset, PRODUCTION_COST, dataName=LABELS[PRODUCTION_COST], mustExist=False)
entryFee = getAssetData(asset, "ENTRY_FEE", mustExist=False)
if entryFee is not None:
	overallProductionCost += entryFee
   
addEnergyConsumption(asset, stateON, availability = "AVAILABILITY_IN", pmaxInOutRatio = PMAX_IN_OUT_RATIO, consumptionCost = overallConsumptionCost)
addEnergyProduction(asset, stateON, productionCost = overallProductionCost)
addGradients(asset, stateON)
finalize(stateON)

```