How the opportunity index is built, everything that has changed
since it was published, what each change did to the numbers, and the exact
sources behind each state.
If you saved a screening result, check the changelog.
Scores move when the method changes, not only when the data does. A result you
forwarded last week may not reproduce today, and the entries below say which
changes moved published scores.
What the index does
For every cell in a hexagonal grid (H3 resolution 8 in built-up areas,
resolution 7 elsewhere) it estimates charging demand from public activity
proxies, subtracts distance-decayed existing charger capacity, and rescales the
result across the state to a 0–100 screening score. It identifies
areas worth investigating. It does not identify viable sites, and it has
never been shown to predict actual charging use.
Standing limitations
Some boundaries are disputed, and we use OpenStreetMap's
Jammu and Kashmir, Ladakh and Arunachal Pradesh are subject to unresolved international disputes. Each grid is clipped to the boundary OpenStreetMap publishes and covers nothing beyond it. That boundary reflects the dispute rather than settling it, so coverage is not a statement about sovereignty or administration by anyone, including us. The single verifiable fact is which polygon was used, and that is the only claim made. Every other boundary in this dataset is uncontested.
No state is validated
Only Telangana has ever been backtested against measured charging consumption, and it failed: no statistically significant correlation (rho=0.04, p=0.69) across 85 metered Hyderabad localities. No other state has been tested at all, because no metered series for them has been found.
Urban extent measures mapping, not settlement
Urban classification comes from OpenStreetMap land-use polygons, and mapping convention differs sharply between states. Andhra Pradesh tags whole revenue villages as residential and has 10,229 km2 of mapped built-up land; Kerala tags smaller parcels and has 479 km2 -- yet Kerala is the more urbanised state. No density threshold can fix this, because any threshold ranks states by how they were mapped.
Scores are relative within a state
Scores are rescaled inside each state, so some cell always approaches 100 and a 100 in one state is not equivalent to a 100 in another.
Private and captive chargers are invisible
No public source lists them, so real supply is higher than shown everywhere.
Sources by state
Sources are declared per state. Nothing here is generated by substituting a
state name into a shared sentence — that practice previously put
Telangana’s distribution utility on four other states’ pages.
TGSPDCL open data (Telangana State Southern Power Distribution Company), via the Telangana Open Data Portal
Backtested against metered electricity consumption for 85 Hyderabad localities: no statistically significant correlation with actual charging use (ρ=0.04, p=0.69).
Telangana Electric Vehicle & Energy Storage Policy 2020–2030
Common to every state: OpenStreetMap contributors (ODbL) for geography and
land use; Open Charge Map contributors (CC BY 4.0) for some station records;
VAHAN (Ministry of Road Transport & Highways) for vehicle registrations;
Ministry of Power / BEE charging-infrastructure guidelines, 17 September 2024.
Changelog
Coverage changedgujarat
Gujarat added
89,130 cells, taking the combined map to nine states and 688,000 cells. Charger power is imputed for 92% of its 575 stations, so it is graded thin evidence.
One figure on this page is lower than the official one and that is deliberate. Gujarat's area is published here as 186,828 km² against an official 196,024 — about 5% short, where every other state lands within 0.3%. Cells are assigned to a state by whether their centre falls inside it, so a cell straddling the coast with its centre offshore is dropped entirely. Gujarat has India's longest and most indented coastline plus two deep marine gulfs, so this costs it far more than anywhere else. Kachchh, the Rann and Saurashtra are all covered — 16,448, 9,157 and 36,039 cells respectively. The figure shown is the area actually screened, which is the number that matters for reading the map.
Effect: No existing score changed. Scores are rescaled within each state, so adding a state never moves another state's numbers.
Coverage changedchhattisgarh, odisha
Chhattisgarh and Odisha added
Chhattisgarh brings 43,898 cells over 135,590 km² and Odisha 49,471 over 156,068 km², taking the combined map past 600,000 cells across eight states. Odisha is the better-evidenced of the two by a wide margin: charger power is imputed for 45% of its 294 stations, against 68% of Chhattisgarh's 130. That puts Odisha on mixed evidence and Chhattisgarh on thin, and Chhattisgarh now has the sparsest station coverage of any state here at three stations per thousand cells.
Both carry an electric bus layer from the day they were added. Chhattisgarh's is unusually clean — the published per-city split of its 240 sanctioned buses (Raipur 100, Durg-Bhilai 50, Bilaspur 50, Korba 40) sums exactly to the state total, which most states' figures do not. Odisha's does not reconcile: three different totals circulate and the reported per-city split sums to 350 against a stated 400, so the seven cities where electric services demonstrably run are shown with no fleet count rather than a number that cannot be right.
Effect: No existing score changed. Scores are rescaled within each state, so adding states never moves another state's numbers.
Coverage changedmaharashtra
Maharashtra added
204,776 cells covering 308,279 km², which makes Maharashtra the largest state in this dataset — the combined map goes from 301,023 cells to 505,799. It carries 1,060 stations, more than any other state here, but charger power is imputed for 93% of them, so it is graded thin evidence on the same uniform test as every other state. No registration data was available for it, so its truck segment rests on the same Grade D hypothesis as the rest.
One thing was checked rather than assumed: 81% of Maharashtra's cells classify as urban, close to Andhra Pradesh's 92%, and Andhra Pradesh carries a warning that its data tags whole revenue villages as residential. Measured the same way, Maharashtra has 5,431 km² of mapped built-up land — 1.8% of the state, against Kerala's 1.2% and Andhra Pradesh's 5.9%. It does not show that pattern, so it does not carry that warning.
Effect: No existing score changed. The combined map now covers a state outside South India, and is named accordingly.
Scores changedall
Restricted and captive chargers no longer count as supply
Each station's access type was recorded but never applied, so gated and staff-only chargers were counted as public supply. A charger the public cannot use does not serve the demand this model estimates, and counting it made underserved areas look served. 116 stations were excluded across the five states (Karnataka 45, Tamil Nadu 27, Kerala 25, Telangana 18, Andhra Pradesh 1). They remain in the registry, graded and sourced; they are excluded only from the supply side of the model.
Effect: Supply fell slightly in affected cells, so their scores rose.
Scores changedall
Station data refreshed
501 stations added across the five states. The new records carry location but not charger power, so the imputed share rose in every state: Kerala 27% to 36%, Tamil Nadu 59% to 65%, Karnataka 48% to 54%, Andhra Pradesh 83% to 90%. More records is not the same as more evidence, and the confidence figures on each page moved accordingly.
Effect: Supply rose where stations were added; confidence fell.
Urban extent is derived from land-use polygons fetched over a rectangular bounding box, and those boxes overlap neighbouring states. Only rural cells had been clipped to the state boundary, so each state's grid contained cells that were not in it -- Kerala held 998 (4.4%), Tamil Nadu 10,017. Kerala's top-ranked truck zone was Irugur, Coimbatore, a Tamil Nadu locality ranked as a Kerala opportunity.
Effect: Cell counts fell; out-of-state areas no longer appear.
Scores changedkerala
Fixed a truncated data fetch that understated urban extent
One OpenStreetMap mirror answered valid queries with a well-formed empty response instead of an error, indistinguishable from a genuine "nothing here". The same query returned 11,078 polygons from one mirror and 1,542 from another within the same minute. Kerala's published data had been collected through the faulty mirror. The mirror was removed, empty results now require confirmation from a second independent mirror, and partial responses (which OpenStreetMap signals with HTTP 200 and a remark field) are rejected.
Effect: Kerala's urban extent had been understated by roughly 10%. Affected cells were re-scored.
Scores changedall
Highway corridors are continuous across state borders
Corridors had been clipped to each state's boundary, so NH-44 was not one route from Telangana into Tamil Nadu but two unrelated stubs in two datasets. Freight routes do not stop at a border, and a corridor just outside a line still serves a cell just inside it.
Effect: Cells near state borders gained corridor adjacency, which raises truck-segment scores there.
Wording onlyall
Confidence figures are per state
Every state page quoted Telangana's 98% charger-power imputation, because the figure was hard-coded rather than read from each state's own data. Kerala's real figure at the time was 27%. The shipped data payload carried the same wrong number.
Effect: No score changed. The stated confidence was wrong before.
Wording onlyall
Evidence grading published
Each state now carries a coarse evidence grade computed the same way for all of them: better-evidenced at 40% imputation or less with 300+ stations; thin at 85% or more, or under 100 stations, or fewer than 5 stations per 1,000 cells. Applied uniformly, this grades Telangana — the first state we published — as thin.
Effect: No score changed. Weak datasets are now labelled as weak.
Full workings
Weights, formulas, the sensitivity analysis and the gap register are
published in the
detailed methodology notes.
Those were written against the Telangana build; the model they describe is the
one every state uses, but the validation results reported there are
Telangana’s alone.