Solve a model region by region

Solves a multi-region model as a series of sub-territory problems — one per region by default, or one per group. Each run is stored as an own-problem variant of a single scenario, so the whole set lives in one folder and is listed by scenario_runs().

The intended use is supply-curve evaluation, where each region is priced against the rest of the system rather than co-optimised with it.

Usage

solve_by_region(
  object,
  name = NULL,
  ...,
  regions = NULL,
  group = NULL,
  trade = c("none", "user", "auto"),
  boundary_prices = NULL,
  share = 0.1,
  nsteps = 3,
  price = NULL,
  spread = 0.5,
  solver = NULL,
  on_error = c("stop", "continue"),
  overwrite = FALSE,
  keep_scenarios = TRUE,
  verbose = TRUE
)

Arguments

object

a model object.

name

character, the sequence name (one scenario folder).

...

passed to interpolate_model() for every region.

regions

character, the regions to solve; defaults to every region of the model, one at a time.

group

a list of character vectors to solve groups of regions together instead of one at a time; overrides regions.

trade

one of "none", "user", "auto" — see Details.

boundary_prices

a boundary_prices data.frame for trade = "user".

share, nsteps, price, spread

passed to boundary_window() for trade = "auto".

solver

a solver option list; the scenario's default when NULL.

on_error

"stop" (default) or "continue" — with "continue" a region that fails to solve is recorded and the run carries on, so one bad region does not lose the rest.

overwrite

logical; FALSE (default) refuses to run when a variant of the same label already exists on disk with a different type or different parameters. TRUE skips that guard and writes into it.

keep_scenarios

logical, keep each region's scenario object.

verbose

logical.

Value

a by_region object: runs (a tibble of what ran, with boundary counting the boundary objects each region faces – a k-step price curve contributes k), scenarios, additive, and failed.

Details

trade decides what replaces the routes that leave a region:

• "none" (default) — routes are dropped and the region is solved in autarky. Because regional quantities are extensive and nothing crosses, the per-region objectives add up to the full model's.

• "user" — boundary_prices is passed through to subset_model_regions().

• "auto" — boundary_window() builds a stepped import/export curve sized at share of the region's own demand in each timeslice. A reference price is required: the window can size the quantity from the model but cannot invent a price.

With trade != "none" each region faces an exterior the others cannot see, so the objectives no longer sum to anything meaningful — the result's additive field records this.

See also

subset_model_regions(), boundary_window(), solve_guided()

Examples

if (FALSE) { # \dontrun{
open_project(tempdir())

ek  <- topia$modules$electricity$R3
mod <- newModel("TOPIA", data = ek$repo,
                calendar = topia$modules$calendars$s4_h24,
                region = ek$regions,
                horizon = topia$modules$horizons$base,
                discount = 0.05)
mod <- setGeoscale(mod, ek$geoscale)

# one solve per region, each seeing priced boundary flows to its neighbours
res <- solve_by_region(mod, name = "BY_REGION", trade = "auto", price = 60,
                       solver = solver_options$glpk)
res$summary
} # }