Engine v2.2.0
A transparent rule-and-data system first. Machine learning later.
Every report stores its input snapshot, rule version, assumptions and timestamp, so any number you see can be audited later. Nothing is randomised and nothing is personalised by who is paying us.
Pipeline
- 01
Normalise inputs
Convert bill to units using your tariff, derive annual consumption, and compute shadow-free usable roof area.
- 02
Generate candidate routes
Subsidy-optimised, consumption-fit, roof-maximised and low-commitment sizes, clamped to a realistic residential range.
- 03
Model each route
Generation, self-consumption vs export, gross cost, central CFA, effective cost, annual savings net of O&M, payback and 25-year value.
- 04
Score and rank
Five weighted dimensions produce a single score; the top route is recommended with its reasons shown.
- 05
Layer subsidy, price and equipment
Application steps, fair-price band with a standardised bill of materials, and three equipment tiers with trade-offs.
- 06
Match installers
Verified installers filtered by pincode or city, size range and status — ordered by empanelment, response time and record.
Scoring weights
| Dimension | Weight | Interpretation |
|---|---|---|
| Consumption fit | 30% | Expected annual generation aligns with realistic consumption. |
| Economic return | 25% | Payback and lifetime value under conservative assumptions. |
| Subsidy capture | 20% | How much of the central CFA the size actually captures. |
| Roof feasibility | 15% | Shadow-free usable area against the area the route needs. |
| Simplicity | 10% | Coordination burden, structure work and approvals at that size. |
Where the data comes from
- Solar resource
- NASA POWER long-term climatology (ALLSKY_SFC_SW_DWN) fetched per city and stored with its coordinates, monthly profile and fetch date. Cities outside our stored set fall back to a conservative placeholder, and your report says so. Source
- Central subsidy
- PM Surya Ghar: Muft Bijli Yojana slabs — ₹30,000 for 1 kW, ₹60,000 for 2 kW and ₹78,000 for 3 kW and above, capped at 3 kW. State or DISCOM top-ups are shown separately and marked verification-required until we can cite them. Source
- Price bands
- Published market price ranges per kW by system size, collected from Indian solar market publications with the date and URL stored alongside each band. Indicative ranges, not quotes.
- Installers
- Company records built from each installer's own public website, with the source URL and the date we read it. Ratings, review counts and install totals are left blank unless we can source them.
Modelling assumptions
These are our engineering choices, not measurements. They are stamped into every report.
- Performance ratio
- 0.78
- Area per kW
- 80 sqft
- Usable roof fraction
- 75%
- Export rate
- ₹2.5/unit surplus
- Degradation
- 0.6% / year
- System life
- 25 years
- O&M
- 1% of capex / year
Shading reduces generation by a factor of 1.00 (none), 0.87 (partial) or 0.70 (heavy). State or DISCOM benefits are never counted in the headline effective cost until they can be verified from an authoritative source.
Scope boundary
Explicitly not in V1
- —EPC work and installation
- —Physical site surveys by SolarRoute
- —Filing your subsidy application for you
- —Collecting customer money or escrow
- —Lending origination
- —Project tracking, AMC and inverter monitoring