Changelog¶

All notable changes to this project will be documented in this file.

The format is based on Keep a Changelog, and this project adheres to Semantic Versioning.

For the complete, detailed changelog, see the CHANGELOG.md file in the repository.

[Unreleased]¶

Added¶

Multi-weather-year support: Filter renewable generation profiles and hourly demand by weather year(s)
Comprehensive DG test suite: Coverage for capacity interpolation/extrapolation, multi-weather-year profiles, aggregation
Flexible interconnection cost specification: New interconnect_capex_mw setting replaces the old per-mile spur line system (capacity_limit_spur_fn)
Supports scalar, region-only, technology-only, and nested patterns
Case-insensitive substring matching with shortest-first precedence for technologies
Automatic annuity calculation for both new and existing resources
Auto-generated cost multiplier mappings: Optional cost_multiplier_region_map and cost_multiplier_technology_map with automatic substring matching
Partial-year DG capacity fill: Interpolate/extrapolate only missing regions when some have the requested year
Regional cost aggregation: Automatic averaging of cost multipliers for aggregated model regions
Simplified fuel workflow: Automatic aggregation of base region fuel prices for aggregated regions

Changed¶

BREAKING: Standardized renewable generation profiles to tidy format only (no more wide format)
Tidy schema: site_id, time_index, value, optional weather_year
BREAKING: Refactored calculate_transmission_inv_cost and add_transmission_inv_cost to use explicit arguments
Functions now read WACC and capital recovery years from dataframe columns
Legacy spur mileage logic only activated when interconnect_capex_mw not provided
Profile IO refactored: Uses centralized DataManager with DNF filters
DG timezone semantics: Negative tz_offset shifts earlier hours later in array
Multi-year DG profiles: Build sequential time_index across weather years
DG aggregation: Uses capacity-weighted averages and requires model_year
Fuel workflow simplified: Legacy mapping parameters (fuel_series_*, fuel_region_map) now optional
Fuel price tables should contain all base regions
Aggregated region prices calculated automatically by averaging base regions

Deprecated¶

Spur line mileage system: transmission_investment_cost with capacity_limit_spur_fn file deprecated in favor of interconnect_capex_mw
Legacy system still functional but emits warnings
Will be removed in a future release

Removed¶

Support for wide-format generation profile files (CSV/Parquet with one column per site)

Version History¶

For detailed version history, including patch releases and full changelogs, visit:

Migration Guides¶

Migrating to v0.8.0¶

Renewable Profile Format¶

Old (Wide Format):

time_index,site_001,site_002,site_003
1,0.45,0.52,0.38
2,0.42,0.48,0.35

New (Tidy Format):

site_id,time_index,value,weather_year
site_001,1,0.45,2012
site_001,2,0.42,2012
site_002,1,0.52,2012
site_002,2,0.48,2012

See Distributed Generation for complete migration details.

Fuel Price Workflow¶

Old (Legacy AEO with mappings):

Settings required multiple mapping parameters:

fuel_data_year: 2025
fuel_series_scenario_names:
  reference: REF2025
fuel_series_names:
  coal: STC
  naturalgas: NG
fuel_series_region_names:
  pacific: PCF
fuel_region_map:
  pacific: [CA_N, CA_S]

Fuel price table had AEO codes:

fuel,region,year,price,scenario
STC,PCF,2030,2.5,REF2025

New (Simplified with complete regional coverage):

Only basic parameters needed:

fuel_scenarios:
  coal: reference
  naturalgas: reference
tech_fuel_map:
  Conventional Steam Coal: coal
  Natural Gas Fired Combined Cycle: naturalgas
fuel_price_table: fuel_prices.csv

Fuel price table contains all base regions:

fuel,region,year,price,scenario
coal,CA_N,2030,2.5,reference
coal,CA_S,2030,2.6,reference
naturalgas,CA_N,2030,4.2,reference
naturalgas,CA_S,2030,4.3,reference

PowerGenome automatically:

Constructs full fuel names: CA_N_reference_coal
Averages prices for aggregated regions (e.g., CA from CA_N + CA_S)

Legacy mapping parameters still supported for backward compatibility.

See Fuel Settings for complete documentation.

Interconnection Costs¶

Old (Per-mile spur line system):

Settings used mileage-based costs:

transmission_investment_cost:
  spur:
    capex_mw_mile:
      CA_N: 3000
      CA_S: 3200
    wacc: 0.069
    investment_years: 60

Extra input file capacity_limit_spur_fn provided spur distances:

resource,region,spur_miles
offshore_wind_fixed,CA_N,45
solar_pv,CA_N,12

New (Direct per-MW cost specification):

Simplified settings with flexible patterns:

interconnect_capex_mw:
  default: 120000
  offshore_wind: 200000  # substring match, case-insensitive
  CA_N:
    battery: 60000
    solar: 105000

No external file needed. Supports:

Scalar (applies to all resources)
Region-only or technology-only mappings
Nested region→technology or technology→region patterns
Shortest-first substring precedence for technology matching

Annuities calculated automatically using plant financial parameters (wacc_real, cap_recovery_years).

Legacy spur system still supported for backward compatibility but will be removed in a future release.

See Settings Documentation for complete interconnect_capex_mw specification.

Contributing¶

Found a bug or have a feature request? See our Contributing guide to get involved!