EV Charging → Question 6

Where Does Fidelity Change the Decision?

146 unique locations across three models. 72 all agree on. The other 74 — 39 A-only and 35 B&C-only — are where fidelity changes the decision.

72
All Models Agree
39
A-Only
35
B&C Only
Cross-Model Agreement Map — 146 Unique Locations
All models agree (49%) A-only (27%) B&C only (24%)

72 of 146 locations (49%): all three models agree. These are the obvious ones — clear demand, good grid access, no controversy. For these, Model A is sufficient.

39 of 146 (27%): unique to Model A. These are city-center sites where Model A's population-based scoring puts chargers. Model B/C's optimization finds these duplicate home charging and redirects to higher-value corridor and suburban locations.

35 of 146 (24%): unique to Model B/C. These are corridor and suburban sites that Model A's scoring formula misses entirely. From Model A's 111 stations, 72 overlap with B/C (65%), while 39 are unique to A (35%). From B/C's 49 stations, most overlap with some A picks, plus 35 locations A never considered.

Model Agreement Breakdown — 146 Unique Locations
Finding
All three models agree on 72 of 146 unique locations — the obvious ones with clear demand and good grid access. Model A uniquely picks 39 city-center sites that duplicate home charging. Model B/C uniquely identify 35 corridor and suburban sites that A's scoring formula misses entirely.
Most sites do not need the grid-aware model. For the 30 where substations run 65–78% loaded, Model C saves an average of $2.3M per station in NPV. The expensive part is not building the model -- it is knowing which 30 stations to run it on.

The Right Model for the Right Question

Question
Right Model
Why
Q1: Gap Analysis
Model A sufficient
237 uncovered tracts found. Population/traffic screening finds the obvious gaps.
Q2–Q3: Placement + Sizing
Model B necessary
88.5% vs 76.1% coverage. Demand-based optimization relocates 35% of stations and right-sizes ports per station.
Q4–Q5: Grid + Cost
Model C essential
$68M NPV savings. 30 of 49 stations can't get full power. Grid check using 4,151 real substations prevents 294 stranded ports.
Q6: Fidelity Map
All three, in sequence
Start simple. Escalate where the decision changes. The pattern: screen → optimize → constrain.

Cross-model comparison: pairwise location matching with 5-mile tolerance.

← Prev Q5: True Cost Study Back to EV Charging Next → Q7: Model Validation