Calculator Inputs
Formula Used
This calculator uses a practical annual production model, then simulates daily soiling buildup, rainfall recovery, and scheduled cleaning recovery.
Baseline Energy = Capacity × Sun Hours × Operating Days × Performance Ratio × (1 − Other Losses)Daily Soiled Energy = Baseline Daily Energy × (1 − Current Soiling Loss)Next Soiling = Current Soiling + Daily Soiling RateSoiling After Rain = Soiling × (1 − Rain Recovery)Soiling After Cleaning = Soiling × (1 − Cleaning Recovery)Revenue Loss = Annual Energy Loss × Energy PriceHow to Use This Calculator
- Enter the solar system capacity in kilowatts.
- Add average sun hours per day for the project location.
- Set the performance ratio to reflect real operating efficiency.
- Enter annual operating days, usually 365 for most systems.
- Input the estimated daily soiling rate from site conditions.
- Choose how often crews clean the modules.
- Enter how much cleaning restores performance.
- Add rainfall frequency and recovery when rain helps wash panels.
- Include other system losses and your energy sale value.
- Press calculate to view annual loss, costs, events, and the monthly chart.
Example Data Table
This example uses the same formula engine as the live calculator.
| Item | Example Value |
|---|---|
| System Capacity | 300.00 kW |
| Sun Hours Per Day | 5.80 |
| Performance Ratio | 84.00% |
| Operating Days | 365 |
| Daily Soiling Rate | 0.16% |
| Cleaning Interval | 28 days |
| Cleaning Recovery | 97.00% |
| Rain Interval | 20 days |
| Rain Recovery | 24.00% |
| Other System Losses | 3.00% |
| Energy Price | $0.11/kWh |
| Calculated Annual Energy Loss | 10,336.36 kWh |
| Calculated Revenue Loss | $1,137.00 |
| Calculated Performance After Soiling | 98.00% |
Frequently Asked Questions
1. What is solar soiling loss?
Solar soiling loss is the energy reduction caused by dust, sand, pollen, bird droppings, and other surface contaminants blocking sunlight from reaching the cells efficiently.
2. Why does this matter on construction projects?
Construction environments often create extra airborne dust. That raises panel soiling rates, lowers output, and changes the cleaning schedule needed during commissioning and early operation.
3. What does daily soiling rate mean?
Daily soiling rate is the estimated percentage of additional performance loss that builds each operating day before rain or manual cleaning restores the module surface.
4. What does cleaning recovery represent?
Cleaning recovery shows how much accumulated soiling is removed during a wash cycle. A higher value means the cleaning process restores more of the lost performance.
5. Can rainfall replace manual cleaning?
Sometimes partly, but not always. Light rain may leave residue, while strong rainfall can remove a meaningful share of dirt. Site conditions decide the actual benefit.
6. Does this calculator include all plant losses?
It includes a separate field for other system losses, but it focuses mainly on soiling behavior, cleaning events, rainfall recovery, energy loss, and revenue impact.
7. How often should panels be cleaned?
The best interval depends on dust conditions, rainfall, labor cost, water access, and energy value. This calculator helps compare those assumptions before setting a schedule.
8. Is this useful for rooftop and utility-scale systems?
Yes. The same logic works for rooftop arrays, ground-mounted systems, and temporary construction-phase solar installations, as long as the input assumptions match the site.