Solar PV yield
Estimate annual AC solar generation from system size, regional irradiation, and one or two roof orientations.
Open calculatorSolar PV payback
Annual generation is split between electricity used directly in the home (saving the full retail purchase price) and surplus exported to the grid under net-billing at your specified export rate. Simple payback divides net installation cost (after grants or subsidies) by first-year bill savings, without modelling inflation, panel degradation or loan interest.
kWp
kWh
kWh/kWp
%
%
Simple payback period
10 years and 5 months
Net cost after subsidy
60,000
Gross cost per kWp
6,000 /kWp
Estimated annual generation
9,306 kWh
Specific yield at this orientation
931 kWh/kWp
First-year bill savings
5,770
Energy consumed on site
2,792 kWh
Surplus exported to grid
6,514 kWh
Remaining grid import
5,208 kWh
Household self-sufficiency share
35%
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Without a battery, typical household self-consumption is 25–35%. Adding home battery storage often raises self-consumption above 50%, though it increases upfront capital cost.
Calculation report (A4 / PDF)
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Simple payback: cost after subsidy divided by annual savings, assuming constant prices and production. Excludes inflation, degradation, financing costs and prosumer deposit limits; the result is not a forecast.
Prices and costs come from the form and may be examples. Regional yield values are indicative; no verified source is available for a specific installation.
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rivermath.com · Prepared locally
This document is for informational purposes only and does not constitute a commercial offer or energy audit.
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Sensitivity analysis
These simulations change only the indicated parameter; all other assumptions match the form. They are not forecasts or confidence intervals. The initial variants are editable examples.
PLN/kWh
PLN/kWh
| Scenario | Grid purchase price per kWh (incl. distribution) (PLN/kWh) | First-year bill savings (PLN/year) | Difference from baseline (PLN/year) |
|---|---|---|---|
| Baseline | 0.9 | 5,769.72 | 0 |
| Variant 1 | 0.72 | 5,267.2 | -502.52 |
| Variant 2 | 1.08 | 6,272.24 | 502.52 |
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