The New Era of Remote Solar Assessment
Historically, assessing whether a rooftop was suitable for photovoltaic (PV) solar panels required physical site visits, manual tape measurements, and expensive preliminary engineering audits. With advancements in high-resolution orbital imaging and web-based GIS technology, remote solar estimation has evolved from a rough estimate into an engineering-grade preliminary design tool.
WGS-84 Ellipsoidal vs Flat-Plane Projection
A common flaw in rudimentary mapping applications is calculating roof area using Web Mercator (EPSG:3857) planar projections. In non-equatorial latitudes, planar calculations can distort surface area measurements by up to 15% to 40%.
GeoArce overcomes this by utilizing Turf.js geodesic algorithms computed directly against the WGS-84 reference ellipsoid: 1. **Geodesic Polygonal Integration**: Each vertex placed by the user represents exact latitude and longitude coordinates. 2. **True Surface Area**: The polygon area is calculated on the earth's curvature rather than a distorted 2D pixel grid. 3. **Usable Pitch & Setback Factor**: We account for standard parapets, ridge setbacks, and chimney clearances with customizable usable area thresholds (defaulting to 70%).
Instant Payback Modeling
- Once the usable surface area is known, GeoArce calculates:
- **Panel Yield**: Estimated count of Tier-1 440W monocrystalline panels.
- **System Peak (kWp)**: Total DC capacity.
- **Annual Yield (kWh)**: Applying latitude-dependent solar irradiance hours (default 4.5 peak sun hours).
- **Financial Payback**: Multiplying annual output by local utility rates ($/kWh, £/kWh, €/kWh, or PKR/kWh) against installed capital expenditure.
The result is instant clarity for homeowners and commercial building managers alike.