Transmission#

dimensions:
  nodes:
    description: Calliope's `nodes` — the places technologies stand at
  techs:
    description: Calliope's `techs` — technologies
  carriers:
    description: Calliope's `carriers` — energy and commodity carriers
  timesteps:
    description: Calliope's `timesteps` — time steps, in order
    dtype: datetime

relations:
  link_from:
    description: >-
      `link_from` — the node a transmission technology links from. Calliope
      reads it as `map_dim(nodes, link_from)`, a mask over technology and
      node, which is the relation's own row test
    key: [techs, nodes]
  link_to:
    description: >-
      `link_to` — the node a transmission technology links to, read as
      `link_from` is
    key: [techs, nodes]

expressions:
  flow_cap_from:
    description: "`where(flow_cap, map_dim(nodes, link_from))` — a link's flow capacity at the node it links from"
    dims: [nodes, techs, carriers]
    cases:
      from:
        when: link_from
        expression: flow_cap
    otherwise: 0
  flow_cap_to:
    description: "`where(flow_cap, map_dim(nodes, link_to))` — a link's flow capacity at the node it links to"
    dims: [nodes, techs, carriers]
    cases:
      to:
        when: link_to
        expression: flow_cap
    otherwise: 0

given:
  parameters:
    base_tech: { dims: [techs], dtype: str }
    carrier_out: { dims: [nodes, techs, carriers], dtype: bool }
  variables:
    flow_cap: { dims: [nodes, techs, carriers] }
  expressions:
    flow_out_inc_eff: { dims: [nodes, techs, carriers, timesteps] }
    flow_in_inc_eff: { dims: [nodes, techs, carriers, timesteps] }

constraints:
  balance_transmission:
    description: "`balance_transmission` — a link puts out at one end, before losses, what it takes in at the other after them"
    dims: [techs, timesteps]
    where: base_tech == 'transmission'
    expression: >-
      sum(flow_out_inc_eff, over=[nodes, carriers])
      == sum(flow_in_inc_eff, over=[nodes, carriers])
  symmetric_transmission:
    description: "`symmetric_transmission` — a link has the same flow capacity at both ends"
    dims: [techs, carriers]
    where: count(carrier_out, over=nodes) >= 1 AND base_tech == 'transmission'
    expression: sum(flow_cap_from, over=nodes) == sum(flow_cap_to, over=nodes)