Realized-savings ledger: counterfactual old-plan cost vs actuals to date

claude-bot commented

2026-07-17 03:09:14 +00:00

Contributor

Add a "since you switched" view: for each month with usage data, price the actual consumption under the baseline plan (Anytime, or a user-pinned baseline) using the existing hourly simulation, and compare against the actual reconciled bill (or the modeled current-plan bill where no actual exists). Accumulate into: total realized savings, battery contribution vs plan-switch contribution (the engine already separates these), and % of battery cost recovered. Surface as a card on Overview and a detail table on Projections or Billing.

Rationale: the entire app answers "what would I save?" — nothing answers "what did I save?", yet the data and engine already exist. This turns the tool from a pre-purchase calculator into an ongoing verdict on the decision.

Requires the timezone fix (#22) and annualization fix (#23) first so the counterfactual is trustworthy. Open Question #15 (authoritative vs derived results) should be answered before building, since this is the first feature that wants durable historical results.

Acceptance criteria

Monthly counterfactual baseline cost computed from actual usage rows
Cumulative realized savings + battery cost recovery % displayed
Months without data clearly excluded, not extrapolated

Relations: relates to #14; blocked by #22, #23; decision dependency #15

(Audit finding F-26, 2026-07-16 — feature, ranked #1 by value-to-effort)

Add a "since you switched" view: for each month with usage data, price the actual consumption under the baseline plan (Anytime, or a user-pinned baseline) using the existing hourly simulation, and compare against the actual reconciled bill (or the modeled current-plan bill where no actual exists). Accumulate into: total realized savings, battery contribution vs plan-switch contribution (the engine already separates these), and % of battery cost recovered. Surface as a card on Overview and a detail table on Projections or Billing. Rationale: the entire app answers "what would I save?" — nothing answers "what did I save?", yet the data and engine already exist. This turns the tool from a pre-purchase calculator into an ongoing verdict on the decision. Requires the timezone fix (#22) and annualization fix (#23) first so the counterfactual is trustworthy. Open Question #15 (authoritative vs derived results) should be answered before building, since this is the first feature that wants durable historical results. **Acceptance criteria** - [ ] Monthly counterfactual baseline cost computed from actual usage rows - [ ] Cumulative realized savings + battery cost recovery % displayed - [ ] Months without data clearly excluded, not extrapolated **Relations:** relates to #14; blocked by #22, #23; decision dependency #15 *(Audit finding F-26, 2026-07-16 — feature, ranked #1 by value-to-effort)*

claude-bot referenced this issue

2026-07-17 03:09:27 +00:00

Outage log with detected candidates and coverage assessment #47

claude-bot added the

enhancement

label

2026-07-17 03:12:00 +00:00

claude-bot referenced this issue

2026-07-17 15:21:15 +00:00

Decide: are calculation results authoritative records or cacheable derivations? #15

Rows
Columns

Realized-savings ledger: counterfactual old-plan cost vs actuals to date #45