Solar Panel Payback & Roof Fit Estimator

Location & Sun

City or Lat/Long (for reference)

Used for documentation only in this prototype.

Avg. Sun Hours / day

Ambient Soiling (%)

Energy Use

Annual Consumption (kWh)

Monthly Breakdown (CSV upload optional)

12 numbers expected. If omitted, an even split or the typical profile is used.

Quick Tips

Sun hours ≈ peak-sun-hours; 4–6 is common.
Soiling reduces annual output. 3–5% is typical in cities.
Upload bills to model seasonal variation.

Roof & Fit

Setback front/back (cm)

Setback sides (cm)

Panel Spacing (cm)

Walkway/Aisles (%)

Panel Orientation

Structural

Panel Geometry

Panel Length (m)

Panel Width (m)

Typical 72/144-cell panel footprint. Spacing adds to these dimensions.

System Design

Module Wattage (W)

Target Offset (%)

DC/AC Ratio

Losses / PR (%)

Shading Level

Inverter Type

Battery (optional)

Enabled

Battery Capacity (kWh)

Battery Power (kW)

Self-Consumption Boost (%)

Optimizer Goal

Prototype optimizer nudges system size during calculation.

Tariff & Policy

Rate (per kWh)

Enter your local currency per kWh.

Fixed Fee (per month)

Export Credit (per kWh)

Tariff Escalation (%/yr)

Self-Consumption (%)

Policy

Notes

For simplicity, TOU/tiered/demand charges are not modeled in this prototype but can be added. Self-consumption can be boosted by batteries and smart load shifting.

Costs, Incentives & Financing

PV Cost (per kWdc)

Battery Cost (per kWh)

O&M (per year)

Inverter Replace Year

Inverter Replace Cost

Incentive / Tax Credit (%)

Discount Rate (%/yr)

Financing

APR (%)

Term (years)

Down Payment (%)

Sensitivity Options

±% for tests

Horizon (years)

Payback

—

NPV

—

IRR

—

LCOE

—

System Summary

Automatically derived from roof fit + design.

Panels	—
kWdc	—
kWac (est)	—
Annual Gen (Yr1)	—
Roof Coverage	—

Layout Summary (per facet)

#	Tilt	Azimuth	Area (m²)	Panels

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