Model/packages
Khalim Conn-Kowlessar 06ce3205b1 slice 17a: PV-export credit in predicted_total_fuel_cost (v2.1.0)
Closes the high-SAP under-prediction gap diagnosed in 16h. 40% of SAP-85+
properties have PV; predicted_ecf was 1.74 mean at that band -> SAP ~88
via the formula, vs label SAP 90+. Inverse: PV homes had HIGHER predicted_ecf
than non-PV at the same band because cost reconstruction had zero export
credit.

New helper: predicted_pv_generation_kwh(kWp, region) -> kWh/yr from a
SAP10.2 Table 6e regional yield factor (UK avg 850 kWh/kWp/yr; Highland
650; Thames 920).

predicted_total_fuel_cost_gbp now subtracts pv_kwh * standard electricity
price (Table 32 code 30, both self-consumption and export at 13.19 p/kWh).

New feature column predicted_pv_generation_kwh exposed alongside the
adjusted cost so the model sees both signals.

VERSION 2.0.0 -> 2.1.0 (MINOR: column added; existing column semantics
shifted but pre-deploy so no consumer break).
2026-05-17 15:28:09 +00:00
..
domain slice 17a: PV-export credit in predicted_total_fuel_cost (v2.1.0) 2026-05-17 15:28:09 +00:00
fetchers added potential file scaffolding: 2026-05-15 10:56:53 +00:00
repos added potential file scaffolding: 2026-05-15 10:56:53 +00:00
utils added potential file scaffolding: 2026-05-15 10:56:53 +00:00
README.md added potential file scaffolding: 2026-05-15 10:56:53 +00:00

Shared packages

Workspace packages consumed by services/*. Each package is its own Python distribution with its own pyproject.toml; services import via the workspace dependency mechanism ({ workspace = true }).

Package Purpose
domain/ Shared domain types — Property, BaselinePerformance, Plan, Scenario, EpcPropertyData, etc. No persistence, no IO, no business logic.
repos/ Persistence layer — one repo per aggregate. Owns the SQL. Depends on domain.
fetchers/ External API clients (gov EPC, Ofgem, Google Solar, etc.). Depend on domain for response shapes.
utils/ Cross-cutting infra — logging, S3, CloudWatch URL builders, SQS task helpers.

Adding a new shared package

Only when a real second consumer materialises. Don't pre-shatter (repos-epc, repos-property, ...) — split when a deployment needs to drop a dep, not before.

See ../ara_backend_design.md §11 for the broader monorepo layout and ../CONTEXT.md for the domain glossary that names the types living in domain/.