Create the new variables and constraints for the multi-year investment for units (i.e., vintage)

[datejada]

• [ ] Create the vintage variables and constraints, but don't link them to the current variables
• [ ] Create the tests for the new variables and constraints

This issue is only for the units. The changes for storage are in #976 and for connections are in #977

Don't change the objective function yet; this will be covered in #912

[manuelma]

Here it would be nice to have a comprehensive list of all the new variables and constraints, and their purpose. For the constraint formulation we could use math assuming constant time resolution and no stochastics.

[datejada]

Here it would be nice to have a comprehensive list of all the new variables and constraints, and their purpose. For the constraint formulation we could use math assuming constant time resolution and no stochastics.

Thanks @manuelma. I have gatter the main changes for this part of the epic issue to put them here and discuss how we should continue. There are three main categories: units, storages, connections. So, in the following comment let's start with the units. Please, add your comments and suggestions.

[datejada]

Changes for the units

New variables

• units_decommissioned(unit,stochastic_scenario,t)
• units_decommissioned_vintage(unit,stochastic_scenario,t_vintage,t)
• units_demothballed_vintage(unit,stochastic_scenario,t_vintage,t)
• units_early_decommissioned_vintage(unit,stochastic_scenario,t_vintage,t)
• units_invested_available_vintage(unit,stochastic_scenario,t_vintage,t)
• units_invested_state(unit,stochastic_scenario,t)
• units_invested_state_vintage(unit,stochastic_scenario,t_vintage,t)
• units_mothballed_state_vintage(unit,stochastic_scenario,t_vintage,t)
• units_mothballed_vintage(unit,stochastic_scenario,t_vintage,t)

New constraints

units_decommissioned(unit=u, stochastic_path=s, t)

simplified version:

units_decommissioned[u, s, t] == sum(tv, units_decommissioned_vintage[u, s, t_v, t])

full version: https://github.com/spine-tools/SpineOpt.jl/blob/7e988de7971afab1b4e503efa9c0c29665ce8d93/src/constraints/constraint_units_decommissioned.jl

units_decommissioned_vintage(unit=u, stochastic_path=s, t_v, t_after)

simplified version:

units_decommissioned_vintage[u, s_after(s), t_v, t_after]
 >=
  + units_invested_state_vintage[u, s_before(s), t_v, t_before(t)]
  - units_invested_state_vintage[u, s_after(s), t_v, t_after(t)]

full version: https://github.com/spine-tools/SpineOpt.jl/blob/7e988de7971afab1b4e503efa9c0c29665ce8d93/src/constraints/constraint_units_decommissioned_vintage.jl

units_invested_available_bound(unit=u, stochastic_path=s, t)

simplified version:

units_invested[u, s, t] <= candidate_units

full version: https://github.com/spine-tools/SpineOpt.jl/blob/7e988de7971afab1b4e503efa9c0c29665ce8d93/src/constraints/constraint_units_invested_available_bound.jl

units_invested_available_vintage(unit=u, stochastic_path=s, t_v, t)

simplified version:

units_invested_available_vintage[u, s, t_v, t]
  ==
   + units_invested_state_vintage[u, s, t_v, t]
   - units_mothballed_state_vintage[u, s, t_v, t]

full version: https://github.com/spine-tools/SpineOpt.jl/blob/7e988de7971afab1b4e503efa9c0c29665ce8d93/src/constraints/constraint_units_invested_available_vintage.jl

units_invested_state(unit=u, stochastic_path=s, t)

simplified version:

units_invested_state[u, s, t] == sum(t_v, units_invested_state_vintage[u, s, t_v, t])

full version: https://github.com/spine-tools/SpineOpt.jl/blob/7e988de7971afab1b4e503efa9c0c29665ce8d93/src/constraints/constraint_units_invested_state.jl

units_invested_state_vintage(unit=u, stochastic_path=s, t_v, t)

simplified version:

units_invested_state_vintage[u, s, t_v, t]
  ==  
   + unit_capacity_transfer_factor * (
        + units_invested[u, s_v(s), t_v]
        - units_early_decommissioned_vintage[u, s_(s), t_v, t_(s)])
   )

full version: https://github.com/spine-tools/SpineOpt.jl/blob/7e988de7971afab1b4e503efa9c0c29665ce8d93/src/constraints/constraint_units_invested_state_vintage.jl

units_mothballed_state_vintage(unit=u, stochastic_path=s, t_v, t_after)

simplified version:

  + units_mothballed_state_vintage[u, s_after(s), t_v, t_after]
  - units_mothballed_state_vintage[u, s_before(s), t_v, t_before(s)] 
 ==
  + units_mothballed_vintage[u, s, t_v, t_after]
  - units_demothballed_vintage[u, s, t_v, t_after]

full version: https://github.com/spine-tools/SpineOpt.jl/blob/7e988de7971afab1b4e503efa9c0c29665ce8d93/src/constraints/constraint_units_mothballed_state_vintage.jl

Modified constraints

The following constraints will link the new variables and constraints to the existing ones. So, This should be in #912

units_invested_available

full version: https://github.com/spine-tools/SpineOpt.jl/blob/7e988de7971afab1b4e503efa9c0c29665ce8d93/src/constraints/constraint_units_invested_available.jl

[datejada]

Close in favour of implementing the multi-year investment through data; see las comment #476