Parameters

NEMO includes a number of parameters that define data and set the terms of constraints for scenarios. As with model dimensions, parameters are specified in a NEMO scenario database. NEMO reads them from the database and uses them to build constraints at run-time. Generally, NEMO does not create separate Julia variables for parameters.

Most parameters are subscripted by one or more dimensions. Parameter tables in a scenario database refer to dimensions by their abbreviation (r for region, t for technology, and so on). The abbreviation serves as the name of the dimension's column, and the column should be populated with unique identifiers for the dimension (val, name, or id, depending on the dimension).

Accumulated annual demand

Exogenous demand that is not time sliced. NEMO ensures the demand is met, but it may be met at any point in the specified year.

Scenario database

Table: AccumulatedAnnualDemand

Annual emission limit

Maximum emissions allowed in the specified year.

Scenario database

Table: AnnualEmissionLimit

Annual exogenous emission

Exogenously specified emissions, assumed to occur regardless of what else is happening in the energy system.

Scenario database

Table: AnnualExogenousEmission

Availability factor

Not currently used.

Capacity factor

Fraction of time a technology is available to operate.

Scenario database

Table: CapacityFactor

Capacity of one technology unit

Increment in which endogenously determined capacity is added for a technology.

Scenario database

Table: CapacityOfOneTechnologyUnit

Capacity to activity unit

Factor relating a region's power unit to its energy unit. See Units of measure.

Scenario database

Table: CapacityToActivityUnit

Capital cost

Cost to build a unit of capacity for the specified technology.

Scenario database

Table: CapitalCost

Capital cost storage

Cost to build a unit of capacity for the specified storage.

Scenario database

Table: CapitalCostStorage

Default parameters

Default value for the parameter identified by tablename.

Scenario database

Table: DefaultParams

Depreciation method

Method for calculating the salvage value of technology, storage, and transmission line capacity existing at the end of the modeling period.

• 1: Sinking fund depreciation (assuming the DiscountRate is not 0; if it is, straight line depreciation is used instead)

• 2: Straight line depreciation

Scenario database

Table: DepreciationMethod

Discount rate

Rate used to discount costs in a region.

Scenario database

Table: DiscountRate

Emission penalty

Cost of emissions.

Scenario database

Table: EmissionsPenalty

Emissions activity ratio

Emission factor for the indicated technology and mode.

Scenario database

Table: EmissionActivityRatio

Fixed cost

Fixed operation and maintenance costs for a technology.

Scenario database

Table: FixedCost

Input activity ratio

Factor multiplied by dispatched capacity to determine the use (input) of the specified fuel. InputActivityRatio is used in conjunction with OutputActivityRatio. A common approach is to:

1. Set the InputActivityRatio for input fuels to the reciprocal of the technology's efficiency.
2. Set the OutputActivityRatio for output fuels to 1.

For example, if a technology had an efficiency of 80%, the InputActivityRatio for inputs would be 1.25, and the OutputActivityRatio for outputs would be 1.0.

Scenario database

Table: InputActivityRatio

Minimum storage charge

Minimum fraction of a storage's capacity that must be charged. NEMO ensures the charge never drops below this level.

Scenario database

Table: MinStorageCharge

Model period emission limit

Maximum emissions allowed in the modeling period (i.e., over all years).

Scenario database

Table: ModelPeriodEmissionLimit

Model period exogenous emission

Exogenously specified emissions, counted toward the model period emission limit regardless of what else is happening in the energy system.

Scenario database

Table: ModelPeriodExogenousEmission

Nodal distribution demand

Fraction of exogenously specified demand for a fuel assigned to a node. If in a given year transmission modeling is enabled for a fuel (see TransmissionModelingEnabled), and the fuel has exogenous demands, the sum of NodalDistributionDemand across nodes should be 1.

Scenario database

Table: NodalDistributionDemand

Nodal distribution storage capacity

Fraction of the specified storage's capacity assigned to the specified node. If NodalDistributionStorageCapacity is defined for a storage in a year, the sum of the parameter across nodes should be 1 for the year.

Scenario database

Table: NodalDistributionStorageCapacity

Nodal distribution technology capacity

Fraction of the specified technology's capacity assigned to the specified node. If NodalDistributionTechnologyCapacity is defined for a technology in a year, the sum of the parameter across nodes should be 1 for the year.

Scenario database

Table: NodalDistributionTechnologyCapacity

Operational life

Lifetime of a technology in years. NEMO uses this parameter to:

1. Retire endogenously determined capacity. If a unit of capacity is built endogenously in year y, NEMO will retire the capacity in year y + OperationalLife.
2. Calculate the salvage value of endogenously determined capacity remaining at the end of the modeling period (see DepreciationMethod).

In this way, the parameter serves as both an operational and an economic lifetime.

Scenario database

Table: OperationalLife

Operational life storage

Lifetime of a storage in years. NEMO uses this parameter to:

1. Retire endogenously determined capacity. If a unit of capacity is built endogenously in year y, NEMO will retire the capacity in year y + OperationalLife.
2. Calculate the salvage value of endogenously determined capacity remaining at the end of the modeling period (see DepreciationMethod).

In this way, the parameter serves as both an operational and an economic lifetime.

Scenario database

Table: OperationalLifeStorage

Output activity ratio

Factor multiplied by dispatched capacity to determine the production (output) of the specified fuel. OutputActivityRatio is used in conjunction with InputActivityRatio. A common approach is to:

1. Set the InputActivityRatio for input fuels to the reciprocal of the technology's efficiency; and
2. Set the OutputActivityRatio for output fuels to 1.

For example, if a technology had an efficiency of 80%, the InputActivityRatio for inputs would be 1.25, and the OutputActivityRatio for outputs would be 1.0.

Scenario database

Table: OutputActivityRatio

Ramp rate

Fraction of a technology's available capacity that can be brought online or taken offline in a time slice and year. Ramp rates determine how quickly a technology's utilization can change. NEMO ignores ramp rates of 1.0 (i.e., 100%) since they effectively don't impose a limit.

Scenario database

Table: RampRate

Ramping reset

Indicator that determines which time slices are exempt from ramp rate limitations. NEMO can set technology utilization to any level in these time slices. The following values are supported for this parameter:

• 0 - Exempts the first time slice in each year.
• 1 - Exempts the first time slice in each time slice group 1 and year.
• 2 - Exempts the first time slice in each time slice group 2, time slice group 1, and year.

Note that because of the way time slices and groups are configured in NEMO, these values build on one another. For example, the first time slice in each year is exempted in all cases, and the first slice in each group 1 and year is exempted when the value is 2. If you don't specify a value for this parameter, NEMO assumes the value is 2.

Scenario database

Table: RampingReset

Renewable energy minimum production target

Fraction of production of fuels tagged with RETagFuel that constitutes a renewable energy target. NEMO ensures that production by technologies tagged with RETagTechnology meets or exceeds the target, pro-rating each technology's production by its RETagTechnology. To take a specific example, suppose that in a given region and year,

• There is one fuel - electricity - whose RETagFuel is 1;

• Total electricity production is 100 (in the region's energy unit);

• REMinProductionTarget is 0.5; and

• There are two technologies, t1 with an RETagTechnology of 0.75 and t2 with an RETagTechnology of 0.5.

Then NEMO will make sure that 75% of t1's production + 50% of t2's production is at least 50 energy units.

Scenario database

Table: REMinProductionTarget

Renewable energy tag fuel

Indicator of whether a fuel is included when calculating the renewable energy minimum production target.

Scenario database

Table: RETagFuel

Renewable energy tag technology

Fraction of a technology's production that counts toward meeting the renewable energy minimum production target.

Scenario database

Table: RETagTechnology

Reserve margin

Multiplier that causes NEMO to deploy extra technology capacity as a reserve. In each year and time slice, NEMO ensures that the capacity of technologies tagged with ReserveMarginTagTechnology is at least ReserveMargin times the rate of production of fuels tagged with ReserveMarginTagFuel. Technology capacity is pro-rated by ReserveMarginTagTechnology in these calculations.

Scenario database

Table: ReserveMargin

Reserve margin tag fuel

Indicator of whether a fuel is included in reserve margin calculations.

Scenario database

Table: ReserveMarginTagFuel

Reserve margin tag technology

Fraction of a technology's capacity that counts toward the reserve margin.

Scenario database

Table: ReserveMarginTagTechnology

Residual capacity

Exogenously specified capacity for a technology. Note that NEMO does not automatically retire this capacity; it is up to you to do so in the values you provide for ResidualCapacity.

Scenario database

Table: ResidualCapacity

Residual storage capacity

Exogenously specified capacity for a storage. Note that NEMO does not automatically retire this capacity; it is up to you to do so in the values you provide for ResidualStorageCapacity.

Scenario database

Table: ResidualStorageCapacity

Specified annual demand

Time-sliced exogenous demand. Use this parameter to specify the total demand in a year, and SpecifiedDemandProfile to assign the demand to time slices. NEMO ensures the demand is met in each time slice.

Scenario database

Table: SpecifiedAnnualDemand

Specified demand profile

Fraction of specified annual demand assigned to a time slice. For a given fuel and year, the sum of SpecifiedDemandProfile across time slices should be 1.

Scenario database

Table: SpecifiedDemandProfile

Storage full load hours

Factor relating endogenously determined capacity for a storage and technologies that discharge it (see TechnologyFromStorage). When this parameter is specified, each unit of endogenous discharging capacity is accompanied by enough endogenous storage capacity to power it for the full load hours.

Scenario database

Table: StorageFullLoadHours

Storage maximum charge rate

Maximum charging rate for a storage.

Scenario database

Table: StorageMaxChargeRate

Storage maximum discharge rate

Maximum discharging rate for a storage.

Scenario database

Table: StorageMaxDischargeRate

Storage start level

Fraction of exogenous storage capacity that is charged at the start of the modeling period.

Scenario database

Table: StorageLevelStart

Technology from storage

Indicator of whether a technology can discharge a storage.

Scenario database

Table: TechnologyFromStorage

Technology to storage

Indicator of whether a technology can charge a storage.

Scenario database

Table: TechnologyToStorage

Time slice group assignment

Map of time slices to time slice groups. Each time slice must belong to one time slice 1 and one time slice group 2.

Scenario database

Table: LTsGroup

Total annual maximum capacity

Maximum capacity for a technology in a year (including both exogenous and endogenous capacity). Only specify this parameter if you want to enforce a particular limit.

Scenario database

Table: TotalAnnualMaxCapacity

Total annual maximum capacity investment

Maximum addition of endogenously determined capacity for a technology in a year. Only specify this parameter if you want to enforce a particular limit.

Scenario database

Table: TotalAnnualMaxCapacityInvestment

Total annual maximum capacity storage

Maximum capacity for a storage in a year (including both exogenous and endogenous capacity). Only specify this parameter if you want to enforce a particular limit.

Scenario database

Table: TotalAnnualMaxCapacityStorage

Total annual maximum capacity investment storage

Maximum addition of endogenously determined capacity for a storage in a year. Only specify this parameter if you want to enforce a particular limit.

Scenario database

Table: TotalAnnualMaxCapacityInvestmentStorage

Total annual minimum capacity

Minimum capacity for a technology in a year (including both exogenous and endogenous capacity). Only specify this parameter if you want to enforce a particular limit (other than 0, which NEMO assumes by default).

Scenario database

Table: TotalAnnualMinCapacity

Total annual minimum capacity investment

Minimum addition of endogenously determined capacity for a technology in a year. Only specify this parameter if you want to enforce a particular limit (other than 0, which NEMO assumes by default).

Scenario database

Table: TotalAnnualMinCapacityInvestment

Total annual minimum capacity storage

Minimum capacity for a storage in a year (including both exogenous and endogenous capacity). Only specify this parameter if you want to enforce a particular limit (other than 0, which NEMO assumes by default).

Scenario database

Table: TotalAnnualMinCapacityStorage

Total annual minimum capacity investment storage

Minimum addition of endogenously determined capacity for a storage in a year. Only specify this parameter if you want to enforce a particular limit (other than 0, which NEMO assumes by default).

Scenario database

Table: TotalAnnualMinCapacityInvestmentStorage

Total technology annual activity lower limit

Minimum nominal energy produced by a technology in a year. Nominal energy is calculated by multiplying dispatched capacity by the length of time it is dispatched. Only specify this parameter if you want to enforce a particular limit (other than 0, which NEMO assumes by default).

Scenario database

Table: TotalTechnologyAnnualActivityLowerLimit

Total technology annual activity upper limit

Maximum nominal energy produced by a technology in a year. Nominal energy is calculated by multiplying dispatched capacity by the length of time it is dispatched. Only specify this parameter if you want to enforce a particular limit.

Scenario database

Table: TotalTechnologyAnnualActivityUpperLimit

Total technology model period activity lower limit

Minimum nominal energy produced by a technology over the modeling period (i.e., all years). Nominal energy is calculated by multiplying dispatched capacity by the length of time it is dispatched. Only specify this parameter if you want to enforce a particular limit (other than 0, which NEMO assumes by default).

Scenario database

Table: TotalTechnologyModelPeriodActivityLowerLimit

Total technology model period activity upper limit

Maximum nominal energy produced by a technology over the modeling period (i.e., all years). Nominal energy is calculated by multiplying dispatched capacity by the length of time it is dispatched. Only specify this parameter if you want to enforce a particular limit.

Scenario database

Table: TotalTechnologyModelPeriodActivityUpperLimit

Trade route

Indicator of whether region r can trade a fuel to region rr.

Scenario database

Table: TradeRoute

Transmission capacity to activity unit

Multiplier to convert 1 megawatt-year to a region's energy unit (e.g., 0.031536 if the energy unit is petajoules). This parameter is required if transmission modeling is enabled (see TransmissionModelingEnabled).

Scenario database

Table: TransmissionCapacityToActivityUnit

Transmission modeling enabled

Indicator of whether transmission modeling is enabled for a region, fuel, and year. The type field specifies the approach to simulating energy flow:

• 1 - Direct current optimized power flow (classical formulation).^[1]
• 2 - Direct current optimized power flow with a disjunctive relaxation.^[2] This formulation produces equivalent results to type 1 but is compatible with a wider range of solvers.
• 3 - Pipeline flow. This approach treats transmission lines as pipelines whose flow is governed only by their maximum flow and efficiency.

Scenario database

Table: TransmissionModelingEnabled

Variable cost

Running cost for a technology, defined in terms of cost per unit of nominal energy produced. Nominal energy is calculated by multiplying dispatched capacity by the length of time it is dispatched.

Scenario database

Table: VariableCost

Year split

Width of a time slice as a fraction of the specified year.

Scenario database

Table: YearSplit