Inter-cluster storage#

dimensions:
  clusters:
    description: Calliope's `clusters` — the representative days a clustered time series is made of
    dtype: int
  datesteps:
    description: Calliope's `datesteps` — the days of the whole time series, in order
    dtype: datetime

relations:
  timestep_cluster:
    description: "`timestep_cluster` — the cluster a time step belongs to"
    key: timesteps
    values: clusters
  lookup_datestep_cluster:
    description: "`lookup_datestep_cluster` — the cluster a day stands for"
    key: datesteps
    values: clusters
  lookup_datestep_last_cluster_timestep:
    description: "`lookup_datestep_last_cluster_timestep` — the last time step of the cluster a day stands for"
    key: datesteps
    values: timesteps

parameters:
  storage_loss:
    description: >-
      `storage_loss` — the share of what a store holds that it loses in an
      hour. Between days it is raised to 24, so it does not vary over time
      steps here
    dims: [nodes, techs]

variables:
  storage:
    description: >-
      `storage` — what a store holds within a clustered day, relative to what
      it carries between days. It may go below zero, as long as the sum does
      not
    bounds: { lower: null }
  storage_inter_cluster:
    description: "`storage_inter_cluster` — what a store carries from one day of the whole time series to the next"
    dims: [nodes, techs, datesteps]
    where: include_storage OR base_tech == 'storage'
    bounds: { lower: 0 }
    absence: zero
  storage_intra_cluster_max:
    description: "`storage_intra_cluster_max` — the most a store holds within a clustered day"
    dims: [nodes, techs, clusters]
    where: include_storage OR base_tech == 'storage'
  storage_intra_cluster_min:
    description: "`storage_intra_cluster_min` — the least a store holds within a clustered day"
    dims: [nodes, techs, clusters]
    where: include_storage OR base_tech == 'storage'

expressions:
  storage_previous_step:
    description: >-
      `$storage_previous_step` under inter-cluster storage — what a store
      carries into a time step: its initial fill at the first step of a store
      that is not cyclic, nothing at the first step of a clustered day, and
      what is left of the step before everywhere else
    cases:
      initial:
        when: position(timesteps) == 0 AND NOT cyclic_storage
        expression: storage_initial * storage_cap
      cluster_start:
        when: lookup_cluster_last_timestep AND NOT (position(timesteps) == 0 AND NOT cyclic_storage)
        expression: "0"
  storage_inter_previous_step:
    description: >-
      `$storage_previous_step` of `balance_storage_inter` — what a store
      carries into a day: its initial fill on the first day of a store that
      is not cyclic, and what is left of the day before everywhere else.
      Calliope reads the initial fill as a share, not times the capacity, as
      here
    dims: [nodes, techs, datesteps]
    cases:
      initial:
        when: position(datesteps) == 0 AND NOT cyclic_storage
        expression: storage_initial
    otherwise: (1 - storage_loss) ** 24 * shift(storage_inter_cluster, along=datesteps, offset=1, edge='wrap')
  storage_intra:
    description: >-
      `$storage_intra` of `balance_storage_inter` — what the clustered day of
      the day before left at its last step, and nothing on the first day of
      a store that is not cyclic
    dims: [nodes, techs, datesteps]
    cases:
      initial:
        when: position(datesteps) == 0 AND NOT cyclic_storage
        expression: "0"
    otherwise: >-
      shift(at(storage, by=lookup_datestep_last_cluster_timestep, over=timesteps, into=datesteps),
      along=datesteps, offset=1, edge='wrap')

constraints:
  storage_max: null
  set_storage_initial:
    description: >-
      `set_storage_initial` under inter-cluster storage — a cyclic store with
      an initial fill carries it between days at the end, after a day's loss
    dims: [nodes, techs, datesteps]
    where: position(datesteps) == -1 AND storage_inter_cluster AND storage_initial AND cyclic_storage
    expression: storage_inter_cluster * (1 - storage_loss) ** 24 == storage_initial * storage_cap
  storage_intra_max:
    description: "`storage_intra_max` — a store holds at most its most within its clustered day"
    dims: [nodes, techs, timesteps]
    where: include_storage OR base_tech == 'storage'
    expression: storage <= at(storage_intra_cluster_max, by=timestep_cluster, over=clusters, into=timesteps)
  storage_intra_min:
    description: "`storage_intra_min` — a store holds at least its least within its clustered day"
    dims: [nodes, techs, timesteps]
    where: include_storage OR base_tech == 'storage'
    expression: storage >= at(storage_intra_cluster_min, by=timestep_cluster, over=clusters, into=timesteps)
  storage_inter_max:
    description: "`storage_inter_max` — what a store carries between days plus the most of its day is at most its capacity"
    dims: [nodes, techs, datesteps]
    where: include_storage OR base_tech == 'storage'
    expression: >-
      storage_inter_cluster + at(storage_intra_cluster_max, by=lookup_datestep_cluster, over=clusters, into=datesteps)
      <= storage_cap
  storage_inter_min:
    description: "`storage_inter_min` — what a store carries between days, after a day's loss, plus the least of its day is not below zero"
    dims: [nodes, techs, datesteps]
    where: include_storage OR base_tech == 'storage'
    expression: >-
      storage_inter_cluster * (1 - storage_loss) ** 24
      + at(storage_intra_cluster_min, by=lookup_datestep_cluster, over=clusters, into=datesteps) >= 0
  balance_storage_inter:
    description: >-
      `balance_storage_inter` — what a store carries into a day is what it
      carried into the day before, after a day's loss, plus what that day's
      cluster left
    dims: [nodes, techs, datesteps]
    where: include_storage OR base_tech == 'storage'
    expression: storage_inter_cluster == storage_inter_previous_step + storage_intra

assumptions:
  cyclic_storage_needs_inter_cluster: null