Model/tests
Khalim Conn-Kowlessar fdd2f60ef2 S0380.187: include electric secondary heating in Appendix M1 D_PV,m — closes gas+PV PE/CO2 gap
The PV onsite/export β-split (SAP 10.2 Appendix M1 §3a, p.93) divides PV
generation by the monthly PV-eligible electricity demand D_PV,m. The cascade
included main and water electricity (when those fuels are electric) but had
no term for SECONDARY space heating. For the 10 cohort-2 gas-main +
electric-secondary + PV certs, the (215)m secondary electric fuel was dropped
from D_PV,m — understating demand in the heating months only, depressing the
monthly β, and under-crediting onsite PV primary energy.

Spec: Appendix M1 §3a counts E_space,m as the dwelling's TOTAL electric
space-heating demand; for a gas-main/electric-secondary dwelling that is the
secondary fuel. Diagnosis was decisive: E_PV (generation) matched the
worksheet exactly every month, the onsite (233a) split diverged ONLY in
heating months (Jun-Sep near-exact), and all 10 affected certs have PV while
all clean gas certs have none. Empirically adding (215)m to D_PV closed cert
3136 onsite 726.9 → 790.3 (worksheet 792.1).

Impact (calc − full-precision dr87 worksheet), the 10 certs:
  PE +0.5..+1.5 → +0.02..+0.046 kWh/m²; CO2 −0.5..−1.1 → +0.002..+0.0095 kg.
The whole 47-cert cohort now matches at PE <0.05 / CO2 <0.025. SAP integers
unchanged; chain SAP 1e-4 pins intact (164 pass). The uniform ~0.03 PE remnant
on PV certs is the separate (233a)/(233b) summer-month D_PV discrepancy.

Re-pinned the 10 worksheet + 9 lodged golden residuals (improvements).
2273 pass, 0 regressions; pyright net-zero (file's 32 errors pre-existing).

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
2026-06-04 15:40:26 +00:00
..
applications refactor(ara): rename FirstRunPipeline → AraFirstRunPipeline (PR #1139 review) 2026-06-01 16:28:48 +00:00
domain S0380.187: include electric secondary heating in Appendix M1 D_PV,m — closes gas+PV PE/CO2 gap 2026-06-04 15:40:26 +00:00
infrastructure Remove EPC and asset_list changes unrelated to SAL handler 2026-06-01 16:39:09 +00:00
orchestration feat(baseline): CalculatorRebaseliner — calculator goes load-bearing (ADR-0013 amend) 2026-06-04 15:40:26 +00:00
repositories feat(fuel-rates): FuelRates snapshot + repository foundation (ADR-0014) 2026-06-04 15:40:26 +00:00
utilities tests framework completed 2026-05-20 14:00:19 +00:00
__init__.py added postcode splitter rewrite to ddd 2026-05-19 16:35:09 +00:00
conftest.py tests framework completed 2026-05-20 14:00:19 +00:00
test_lambda_packaging.py more tests to ensure we don't deploy something that is brokern 2026-06-02 15:03:20 +00:00