# Solar Panel Output Calculator

URL: https://speedycalculator.com/calculators/ecology/solar-panel/
Last updated: 2026-10-25

> The solar panel calculator estimates the daily and yearly energy a solar array produces from the system size in kilowatts, average peak sun hours and system losses, plus the yearly savings.

## Inputs

- System size (kW)
- Peak sun hours per day
- System losses (%)
- Electricity price per kWh

## Results

- Energy per day
- Energy per year
- Value per year

## Formula

```
Daily energy = system kW × peak sun hours × (1 − losses)
```

## Explanation

Peak sun hours vary by location and season, from about 3 in northern Europe to 6–7 in deserts. Lahore averages roughly 5.

### How to use the Solar Panel Output Calculator

- **System size**
- **Peak sun hours per day**
- **System losses**
- **Electricity price per kWh**

Results update as you type, and every field accepts the units shown in its menu.

### How it works

System size is multiplied by sun hours, then reduced for inverter, wiring, dirt and temperature losses.

### Inputs explained

FieldWhat to enterSystem sizeIn kWPeak sun hours per dayA numberSystem lossesIn %Electricity price per kWhAmount in your currency

### What each result means

- **Energy per day** = [System size]×[Peak sun hours per day]×(1 - [System losses]÷100)
- **Energy per year** = [Energy per day]×365
- **Value per year** = [Energy per year]×[Electricity price per kWh]

### Example values

How the main result changes when **System size** changes and everything else stays at the example values above:

System size (kW)Energy per year (kWh)2.53,9243.755,88657,8486.259,8097.511,7711015,695

## Worked example

Inputs — System size: 5 kW; Peak sun hours per day: 5; System losses: 14 %; Electricity price per kWh: $0.18.

Results — Energy per day = 21.5 kWh; **Energy per year = 7,848 kWh**; Value per year = $1,412.55.

## FAQ

**What are peak sun hours?**
The equivalent hours per day of 1,000 W/m² sunlight.

**Where can I get local solar data?**
NREL’s PVWatts tool gives estimates for any location.

**What formula does the Solar Panel Output Calculator use?**
Daily energy = system kW × peak sun hours × (1 − losses).


## Sources

- [NREL PVWatts Calculator](https://pvwatts.nrel.gov/)