An S4 class to represent storage type of technological process.

Storage type of technological processes with accumulating capacity of a commodity.

Details

Storage can be used in combination with other processes, such as technologies, supply, or demand to represent complex technological chains, demand or supply technologies with time-shift. Operation of storage includes accumulation, storing, and release of the stored commodity. The storing cycle operates on the ordered time-timeslices of the commodity timeframe. The cycle is looped either on an annual basis (last time-timeslice of a year follows the first time timeslice of the same year) or within the parent time-frame (for example, when commodity time-frame is "HOUR" and the parent time-frame is "DAY" then the storage cycle will be a calendar day).

Slots

name

character. Name of the storage (used in sets).

desc

character. Description of the storage.

aux

data.frame. Auxiliary commodities.

acomm: character. Name of the auxiliary commodity (used in sets).
unit: character. Unit of the auxiliary commodity.

region

character. Region where the storage technology exists or can be installed.

cluster

data.frame. Declaration of the storage clusters – parallel sub-processes of the same storage with their own capacity, availability and costs. The motivating cases are site-constrained storage (pumped-hydro head classes, CAES caverns) and duration classes via a per-cluster duration. Optional: when empty, cluster labels are harvested from the other slots; when populated it is authoritative and an undeclared label raises an error.

cluster: character. Cluster label. Must match the cluster column values used in the other slots.
desc: character. Human-readable description of the cluster, used in reports.
region: character. Region the cluster exists in, NA for every region.
order: integer. Optional display/ranking order; controls the order variants are created and reported in.

vintage

data.frame. Investment window and operational life of the storage, one row per (vintage, region, cluster). Replaces the former start, end and olife slots. A vintage is a separately investable variant that keeps the characteristics of its build year for its whole life – for storage typically a falling capex and a rising round-trip efficiency.

vintage: character. Vintage label, normally the build year as a string. NA for an un-vintaged storage.
region: character. Region name to apply the parameter, NA for every region.
cluster: character. Cluster label, NA for every cluster.
start: integer. The first year the storage can be installed. NA means unbounded (up to end).
end: integer. The last year the storage can be installed. NA means unbounded (from start on).
olife: integer. Operational life of the storage in years, applicable to new investment only.

capacity

data.frame. Capacity parameters of the storage technology.

vintage: character. Vintage label selecting the variant this row applies to, NA for every vintage. See the vintage slot.
cluster: character. Cluster label selecting the variant this row applies to, NA for every cluster. See the cluster slot.
region: character. Region name to apply the parameter, NA for every region.
year: integer. Year to apply the parameter, NA for every year.
out.stock: numeric. Existing (exogenous) capacity of the discharging part – the power the store can deliver, in power units.
out.cap.lo: numeric. Lower bound of the discharging part – the power the store can deliver capacity.
out.cap.up: numeric. Upper bound of the discharging part – the power the store can deliver capacity.
out.cap.fx: numeric. Fixed value of the discharging part – the power the store can deliver capacity. Overrides out.cap.lo and out.cap.up.
out.ncap.lo: numeric. Lower bound of the discharging part – the power the store can deliver new capacity.
out.ncap.up: numeric. Upper bound of the discharging part – the power the store can deliver new capacity.
out.ncap.fx: numeric. Fixed value of the discharging part – the power the store can deliver new capacity. Overrides out.ncap.lo and out.ncap.up.
out.ret.lo: numeric. Lower bound of the discharging part – the power the store can deliver capacity retirement.
out.ret.up: numeric. Upper bound of the discharging part – the power the store can deliver capacity retirement.
out.ret.fx: numeric. Fixed value of the discharging part – the power the store can deliver capacity retirement. Overrides out.ret.lo and out.ret.up.
inp.stock: numeric. Existing (exogenous) capacity of the charging part – the power the store can absorb, in power units.
inp.cap.lo: numeric. Lower bound of the charging part – the power the store can absorb capacity.
inp.cap.up: numeric. Upper bound of the charging part – the power the store can absorb capacity.
inp.cap.fx: numeric. Fixed value of the charging part – the power the store can absorb capacity. Overrides inp.cap.lo and inp.cap.up.
inp.ncap.lo: numeric. Lower bound of the charging part – the power the store can absorb new capacity.
inp.ncap.up: numeric. Upper bound of the charging part – the power the store can absorb new capacity.
inp.ncap.fx: numeric. Fixed value of the charging part – the power the store can absorb new capacity. Overrides inp.ncap.lo and inp.ncap.up.
inp.ret.lo: numeric. Lower bound of the charging part – the power the store can absorb capacity retirement.
inp.ret.up: numeric. Upper bound of the charging part – the power the store can absorb capacity retirement.
inp.ret.fx: numeric. Fixed value of the charging part – the power the store can absorb capacity retirement. Overrides inp.ret.lo and inp.ret.up.
stg.stock: numeric. Existing (exogenous) capacity of the reservoir itself – the energy the store can hold, in energy units.
stg.cap.lo: numeric. Lower bound of the reservoir itself – the energy the store can hold capacity.
stg.cap.up: numeric. Upper bound of the reservoir itself – the energy the store can hold capacity.
stg.cap.fx: numeric. Fixed value of the reservoir itself – the energy the store can hold capacity. Overrides stg.cap.lo and stg.cap.up.
stg.ncap.lo: numeric. Lower bound of the reservoir itself – the energy the store can hold new capacity.
stg.ncap.up: numeric. Upper bound of the reservoir itself – the energy the store can hold new capacity.
stg.ncap.fx: numeric. Fixed value of the reservoir itself – the energy the store can hold new capacity. Overrides stg.ncap.lo and stg.ncap.up.
stg.ret.lo: numeric. Lower bound of the reservoir itself – the energy the store can hold capacity retirement.
stg.ret.up: numeric. Upper bound of the reservoir itself – the energy the store can hold capacity retirement.
stg.ret.fx: numeric. Fixed value of the reservoir itself – the energy the store can hold capacity retirement. Overrides stg.ret.lo and stg.ret.up.

input

data.frame. The commodity that FILLS the store – the "charger" side. Named by comm, with an optional unit. Left empty it takes whatever newStorage(commodity = ) supplied.

comm: character. Commodity consumed to fill the store.
unit: character. Unit of comm on this side, exactly as on technology@input/ @output. Descriptive only: it is carried for reporting and convert() and never reaches the solver. It is the unit of the COMMODITY (e.g. MWh), not of the capacity – capacity units follow from cap2act, and the storing side has no cap2act because a reservoir is an amount rather than a rate.
cap2act: numeric. Capacity to ANNUAL flow, exactly as technology@cap2act. The flow bound is inp.af.up * cap2act * cap * pTimesliceShare, so cap is a RATE and means the same physical thing on any calendar. Defaults to 8760 (hours in a year), which makes cap read as commodity per HOUR; an hourly full-year model is unchanged because 8760 * (1/8760) = 1. Assumes commodity unit = capacity unit x hour (GW with GWh); GW with TWh wants 8.76. The STORING side has no cap2act – energy is energy at any resolution.

output

data.frame. The commodity the store RELEASES – the "discharger" side. Named by comm, with an optional unit. Left empty it takes whatever newStorage(commodity = ) supplied.

comm: character. Commodity produced when the store discharges.
unit: character. Unit of comm on this side, exactly as on technology@input/ @output. Descriptive only: it is carried for reporting and convert() and never reaches the solver. It is the unit of the COMMODITY (e.g. MWh), not of the capacity – capacity units follow from cap2act, and the storing side has no cap2act because a reservoir is an amount rather than a rate.
cap2act: numeric. Capacity to ANNUAL flow, exactly as technology@cap2act. The flow bound is inp.af.up * cap2act * cap * pTimesliceShare, so cap is a RATE and means the same physical thing on any calendar. Defaults to 8760 (hours in a year), which makes cap read as commodity per HOUR; an hourly full-year model is unchanged because 8760 * (1/8760) = 1. Assumes commodity unit = capacity unit x hour (GW with GWh); GW with TWh wants 8.76. The STORING side has no cap2act – energy is energy at any resolution.

storage

data.frame. The commodity the store HOLDS – what vStorageLevel is measured in. Named by comm, with an optional unit. Left empty it takes whatever newStorage(commodity = ) supplied. It may differ from BOTH flows: a hydrogen store consumes and produces electricity while holding hydrogen. There is no commodity slot – newStorage(commodity = ) is a shorthand folded into these three at construction, so an object never carries two answers to what it consumes. Beyond comm, this slot carries the storing side's OWN capacity and economics, measured in ENERGY (e.g. MWh) rather than power. Supplying any of them materialises vStorageStgCap, so the store's energy can be sized, bounded and priced independently of its inverter; supplying none of them (a bare comm) leaves the storage with a single power capacity and the pre-v0.84 model, with @duration inlined into the availability bounds.

comm: character. Commodity the store HOLDS – what vStorageLevel is measured in.
unit: character. Unit of comm. Descriptive only, carried for reporting and convert() and never reaching the solver. There is no cap2act on this side – energy is energy at any resolution.

startLevel

data.frame. Energy added to the storage level ONCE PER CYCLE, at the first timeslice of the cycle. There is deliberately no timeslice column: the slice is derived from the calendar and fullYear, so it cannot be left unset and broadcast to every timeslice the way the old charge slot could. Which cycle depends on fullYear: once a year when TRUE, once per parent timeframe when FALSE. The value is ANNUAL. When the cycle is shorter than a year each cycle receives its own SHARE of it – 365 daily cycles get 1/365 each – so the annual endowment is the same however the cycle closes. A calendar covering part of a year endows that fraction, consistently. It is FREE to the model, by design and unavoidably – a store that ends a cycle below where it started has consumed an endowment nobody paid for. PyPSA's state_of_charge_initial has the same property. Being additive, the level at the first timeslice is startLevel PLUS whatever carried over from the previous cycle, i.e. at least startLevel rather than exactly it; the model may end the cycle empty to make it exact. Renamed from charge (via inflow) in v0.80; both are still accepted with a warning, and any timeslice column they carried is dropped. NOTE hydro inflow does NOT belong here – use a weather-driven supply (with ava.up, so spilling is free) feeding the storage.

vintage: character. Vintage label selecting the variant this row applies to, NA for every vintage. See the vintage slot.
cluster: character. Cluster label selecting the variant this row applies to, NA for every cluster. See the cluster slot.
region: character. Region name to apply the parameter, NA for every region.
year: integer. Year to apply the parameter, NA for every year.
startLevel: numeric. Energy added to the level at the first timeslice of each cycle.

seff

data.frame. Storage efficiency parameters.

vintage: character. Vintage label selecting the variant this row applies to, NA for every vintage. See the vintage slot.
cluster: character. Cluster label selecting the variant this row applies to, NA for every cluster. See the cluster slot.
region: character. Region name to apply the parameter, NA for every region.
year: integer. Year to apply the parameter, NA for every year.
timeslice: character. Time timeslice to apply the parameter, NA for every timeslice.
stgeff: numeric. Storage decay annual rate.
inpeff: numeric. Input efficiency rate.
outeff: numeric. Output efficiency rate.

af

data.frame. Availability factor parameters. Unlike a technology's af (which bounds activity, a flow), the storage af.* columns bound the stored LEVEL – a stock – as a fraction of the storing capacity, i.e. a state-of-charge range. They are not capacity factors. The flow-side bounds are the cinp.*/cout.* columns, which bound charge/discharge relative to the charger/discharger capacity per timeslice (those are the storage analogue of a technology's af).

vintage: character. Vintage label selecting the variant this row applies to, NA for every vintage. See the vintage slot.
cluster: character. Cluster label selecting the variant this row applies to, NA for every cluster. See the cluster slot.
region: character. Region name to apply the parameter, NA for every region.
year: integer. Year to apply the parameter, NA for every year.
timeslice: character. Time timeslice to apply the parameter, NA for every timeslice.
af.lo: numeric. Lower bound of the stored level as a fraction of storing capacity (minimum state of charge).
af.up: numeric. Upper bound of the stored level as a fraction of storing capacity (maximum state of charge).
af.fx: numeric. Fixed value of the stored-level fraction. This parameter overrides af.lo and af.up.
inp.af.lo: numeric. Lower bound of the charging (input) flow relative to charger capacity per timeslice.
inp.af.up: numeric. Upper bound of the charging (input) flow relative to charger capacity per timeslice.
inp.af.fx: numeric. Fixed value of the charging (input) flow relative to charger capacity per timeslice. This parameter overrides inp.af.lo and inp.af.up.
out.af.lo: numeric. Lower bound of the discharging (output) flow relative to discharger capacity per timeslice.
out.af.up: numeric. Upper bound of the discharging (output) flow relative to discharger capacity per timeslice.
out.af.fx: numeric. Fixed value of the discharging (output) flow relative to discharger capacity per timeslice. This parameter overrides out.af.lo and out.af.up.

aeff

data.frame. Auxiliary commodities efficiency parameters.

vintage: character. Vintage label selecting the variant this row applies to, NA for every vintage. See the vintage slot.
cluster: character. Cluster label selecting the variant this row applies to, NA for every cluster. See the cluster slot.
acomm: character. Name of the auxiliary commodity (used in sets).
region: character. Region name to apply the parameter, NA for every region.
year: integer. Year to apply the parameter, NA for every year.
timeslice: character. Time timeslice to apply the parameter, NA for every timeslice.
stg2ainp: numeric. Storaage-level-to-auxiliary-input-commodity coefficient (multiplier).
cinp2ainp: numeric. Input-commodity-to-auxiliary-input-commodity coefficient (multiplier).
cout2ainp: numeric. Output-commodity-to-auxiliary-input-commodity coefficient (multiplier).
stg2aout: numeric. Storage-level-to-auxiliary-output-commodity coefficient (multiplier).
cinp2aout: numeric. Input-commodity-to-auxiliary-output-commodity coefficient (multiplier).
cout2aout: numeric. Output-commodity-to-auxiliary-output-commodity coefficient (multiplier).
cap2ainp: numeric. Capacity-to-auxiliary-input-commodity coefficient (multiplier).
cap2aout: numeric. Capacity-to-auxiliary-output-commodity coefficient (multiplier).
ncap2ainp: numeric. New-capacity-to-auxiliary-input-commodity coefficient (multiplier).
ncap2aout: numeric. New-capacity-to-auxiliary-output-commodity coefficient (multiplier).
pho2ainp: numeric. Aux commodity CONSUMED when capacity reaches the END OF ITS LIFE (demolition energy, labour). Multiplies the per-year phase-out FLOW, so the charge lands ONCE – in the milestone where the capacity disappears – not every year it stood. NO pTimesliceShare is applied and the aux balance is PER TIMESLICE, so a value given with timeslice = NA applies in EVERY slice and the annual total comes out multiplied by the slice count – 8760x on an hourly calendar. Give a per-slice value, or name a single slice.
pho2aout: numeric. Aux commodity RELEASED when capacity reaches the END OF ITS LIFE (demolition waste, recovered material). Fires even when optimizeRetirement is FALSE, which is the usual case. NO pTimesliceShare is applied and the aux balance is PER TIMESLICE, so a value given with timeslice = NA applies in EVERY slice and the annual total comes out multiplied by the slice count – 8760x on an hourly calendar. Give a per-slice value, or name a single slice.
ret2ainp: numeric. Aux commodity CONSUMED when capacity is retired EARLY. Separate from pho2ainp because the two differ physically: scrapping an intact plant is not the same job as demolishing a worn-out one. NO pTimesliceShare is applied and the aux balance is PER TIMESLICE, so a value given with timeslice = NA applies in EVERY slice and the annual total comes out multiplied by the slice count – 8760x on an hourly calendar. Give a per-slice value, or name a single slice.
ret2aout: numeric. Aux commodity RELEASED when capacity is retired EARLY (scrap). Usually LARGER than pho2aout: a plant retired before its time is still largely intact, so more material is recoverable. NO pTimesliceShare is applied and the aux balance is PER TIMESLICE, so a value given with timeslice = NA applies in EVERY slice and the annual total comes out multiplied by the slice count – 8760x on an hourly calendar. Give a per-slice value, or name a single slice.
ncap2stg: numeric. New-capacity-to-storage-level coefficient (multiplier).

fixom

data.frame. Fixed operation and maintenance cost.

vintage: character. Vintage label selecting the variant this row applies to, NA for every vintage. See the vintage slot.
cluster: character. Cluster label selecting the variant this row applies to, NA for every cluster. See the cluster slot.
region: character. Region name to apply the parameter, NA for every region.
year: integer. Year to apply the parameter, NA for every year.
out.fixom: numeric. Fixed operation and maintenance cost per unit of installed capacity of the discharging part – the power the store can deliver.
inp.fixom: numeric. Fixed operation and maintenance cost per unit of installed capacity of the charging part – the power the store can absorb.
stg.fixom: numeric. Fixed operation and maintenance cost per unit of installed capacity of the reservoir itself – the energy the store can hold.

varom

data.frame. Variable operation and maintenance cost.

vintage: character. Vintage label selecting the variant this row applies to, NA for every vintage. See the vintage slot.
cluster: character. Cluster label selecting the variant this row applies to, NA for every cluster. See the cluster slot.
region: character. Region name to apply the parameter, NA for every region.
year: integer. Year to apply the parameter, NA for every year.
timeslice: character. Time timeslice to apply the parameter, NA for every timeslice.
inpcost: numeric. Costs associated with the input commodity.
outcost: numeric. Costs associated with the output commodity.
stgcost: numeric. Costs associated with the storage level.

invcost

data.frame. Investment cost.

vintage: character. Vintage label selecting the variant this row applies to, NA for every vintage. See the vintage slot.
cluster: character. Cluster label selecting the variant this row applies to, NA for every cluster. See the cluster slot.
region: character. Region name to apply the parameter, NA for every region.
year: integer. Year to apply the parameter, NA for every year.
out.invcost: numeric. Investment cost per unit of new capacity of the discharging part – the power the store can deliver.
out.wacc: numeric. Cost of capital used to annuitise the discharging part – the power the store can deliver investment (overrides pWacc).
out.payback: numeric. Cost-recovery period of the discharging part – the power the store can deliver, in years (overrides the operational life in the EAC charge).
out.eac: numeric. Equivalent annual cost of the discharging part – the power the store can deliver, supplied directly instead of being annuitised from invcost.
out.retcost: numeric. Cost of retiring the discharging part – the power the store can deliver early.
inp.invcost: numeric. Investment cost per unit of new capacity of the charging part – the power the store can absorb.
inp.wacc: numeric. Cost of capital used to annuitise the charging part – the power the store can absorb investment (overrides pWacc).
inp.payback: numeric. Cost-recovery period of the charging part – the power the store can absorb, in years (overrides the operational life in the EAC charge).
inp.eac: numeric. Equivalent annual cost of the charging part – the power the store can absorb, supplied directly instead of being annuitised from invcost.
inp.retcost: numeric. Cost of retiring the charging part – the power the store can absorb early.
stg.invcost: numeric. Investment cost per unit of new capacity of the reservoir itself – the energy the store can hold.
stg.wacc: numeric. Cost of capital used to annuitise the reservoir itself – the energy the store can hold investment (overrides pWacc).
stg.payback: numeric. Cost-recovery period of the reservoir itself – the energy the store can hold, in years (overrides the operational life in the EAC charge).
stg.eac: numeric. Equivalent annual cost of the reservoir itself – the energy the store can hold, supplied directly instead of being annuitised from invcost.
stg.retcost: numeric. Cost of retiring the reservoir itself – the energy the store can hold early.

fullYear

logical. Controls where the charge/discharge cycle closes. If TRUE (default), the storage operates across parent timeframes through the whole year: the preceding time-timeslice of the first time-timeslice of a group is the last time-timeslice of the PREVIOUS group, and only the last time-timeslice of the year wraps round to the first. A battery on an hourly calendar nested under days can therefore carry energy from one day into the next, and seasonal storage is representable. If FALSE, the cycle is closed within each parent timeframe: the preceding time-timeslice of the first time-timeslice of a group is the LAST time-timeslice of the SAME group, so every group is an independent loop with no energy carried between them.

duration

data.frame. How long the store can run at its rated output: the ratio of storing capacity to (dis)charging capacity. duration = 6 on an hourly calendar is a 6-hour store. Renamed from cap2stg in v0.80, which is still accepted with a warning. It is a BOUND on (storage, region, year): duration.fx ties energy to power, duration.lo/duration.up let the model choose the ratio – which only bites when the storing side is priced, via @storage$invcost. The bare duration column is the scalar shorthand and is normalised to duration.fx at construction. A ONE-SIDED range opens the other side (an up alone does not inherit the default lo of 1). Saying nothing leaves the slot empty and the parameter default of [1, 1] ties energy to power at one hour, which is the pre-v0.84 behaviour.

vintage: character. Vintage label selecting the variant this row applies to, NA for every vintage.
cluster: character. Cluster label selecting the variant this row applies to, NA for every cluster.
region: character. Region name to apply the parameter, NA for every region.
year: integer. Year to apply the parameter, NA for every year.
duration: numeric. Capacity-to-storage ratio (storage duration).
duration.lo: numeric. Lower bound on the energy-to-power ratio, in hours.
duration.up: numeric. Upper bound on the energy-to-power ratio, in hours.
duration.fx: numeric. Fixed energy-to-power ratio, in hours. The scalar shorthand duration = 6 normalises to this.

inp2out

data.frame. The charge-to-discharge capacity ratio, dimensionless: how big the charger is relative to the discharger. Same bound semantics as duration – inp2out.fx ties the two (one bidirectional inverter), inp2out.lo/.up let the model size them apart, and the bare inp2out column is the scalar shorthand, normalised to .fx at construction. A one-sided range opens the other side. Saying nothing leaves the slot empty and the parameter default of [1, 1] keeps the two sides symmetric, which is what a storage without a separate charger has always been. It bites only when the charging side is priced or bounded via @input; otherwise there is no charging capacity variable to constrain.

vintage: character. Vintage label selecting the variant this row applies to, NA for all.
cluster: character. Cluster label selecting the variant this row applies to, NA for all.
region: character. Region the row applies to, NA for all.
year: integer. Year the row applies to, NA for all.
inp2out: numeric. Scalar shorthand, normalised to inp2out.fx.
inp2out.lo: numeric. Lower bound on the charge-to-discharge capacity ratio.
inp2out.up: numeric. Upper bound on the charge-to-discharge capacity ratio.
inp2out.fx: numeric. Fixed charge-to-discharge capacity ratio.

weather

data.frame. Weather factors multipliers.

vintage: character. Vintage label selecting the variant this row applies to, NA for every vintage. See the vintage slot.
cluster: character. Cluster label selecting the variant this row applies to, NA for every cluster. See the cluster slot.
weather: character. Name of the weather factor to apply.
waf.lo: numeric. Coefficient that links the weather factor with the lower bound of the availability factor.
waf.up: numeric. Coefficient that links the weather factor with the upper bound of the availability factor.
waf.fx: numeric. Coefficient that links the weather factor with the fixed value of the availability factor. This parameter overrides waf.lo and waf.up.
inp.waf.lo: numeric. Coefficient that links the weather factor with the lower bound of the input commodity availability factor.
inp.waf.up: numeric. Coefficient that links the weather factor with the upper bound of the input commodity availability factor.
inp.waf.fx: numeric. Coefficient that links the weather factor with the fixed value of the input commodity availability factor. This parameter overrides inp.waf.lo and inp.waf.up.
out.waf.lo: numeric. Coefficient that links the weather factor with the lower bound of the output commodity availability factor.
out.waf.up: numeric. Coefficient that links the weather factor with the upper bound of the output commodity availability factor.
out.waf.fx: numeric. Coefficient that links the weather factor with the fixed value of the output commodity availability factor. This parameter overrides out.waf.lo and out.waf.up.

optimizeRetirement

logical. Incidates if the retirement of the storage should be optimized. Also requires the same parameter in the model or scenario class to be set to TRUE to be effective.

misc

list. List of additional parameters that are not used in the model but can be used for reference or user-defined functions. For example, links to the source of the storage data, or other metadata.