Economic impacts of dirty photovoltaic panels

There are studies showing that after just one year without maintenance, a panel loses up to 12% of its power due to dirt. It is not enough that the panels are tilted and washed by rain. In cities, the ubiquitous dust and acid rain are to blame for panel soiling, while on the plains, both dust and plant pollen and bird droppings combine. Moreover, for example, photovoltaic panels mounted in an aluminium frame become fouled after a while by the very chemicals that escape from the panel frame.

The economic impact of dirty PV panels
Pollution of solar panels not only affects their technical performance but also has significant economic consequences.

Losses in electricity generation
On average, the power losses caused by pollution can reach 20-40%, which means a significant reduction in energy production and thus in financial returns. For example, for a 10 kWp photovoltaic system producing 10 000 kWh per year, pollution can cause a loss of 2 000 to 4 000 kWh per year. At an average electricity price of 0.17 €/kWh, this represents a loss of 340-680 € per year.

Cleaning costs versus savings
Although professional cleaning of the panels costs approximately €100-150 per cleaning, the recommended two cleanings per year represents an investment of €200-300 per year. However, this amount is significantly less than the potential loss in electricity generation, so cleaning is clearly worthwhile. The average return on investment (ROI ) for cleaning is between 20-80%, with a return on investment in as little as 7-10 months.

Long-term impacts on panel lifetime
If the panels are not cleaned regularly, their performance gradually decreases, shortening their lifetime. Dirt build-up can cause parts of the panel to overheat (hot spots), which can lead to permanent cell damage and the need for replacement. Regular maintenance can extend the life of the panels by 5 to 10 years and reduce the cost of replacement.

Extending the return on investment
Contaminated PV panels affect not only their performance but also the payback period of the investment. If panels are not cleaned regularly, their efficiency can drop by up to 20%, causing significant financial losses.

Calculating the payback extension

• A 10 kWp PV system costs €12,000.
• Annual electricity production without pollution: 12 000 kWh.
• At an electricity price of €0.17/kWh, the annual saving is €2,040.
• Return on investment without pollution: 5.88 years.

If the panels are dirty and their output drops by 20%:

• Annual electricity production drops to: 9,600 kWh.
• The annual saving drops to: €1,632.
• New return on investment: 7 .35 years.

How often to clean the panels?
The frequency of panel cleaning depends on the inclination of the installation and the type of panels, and the frequency and technology of the cleaning itself is chosen accordingly. The frequency of cleaning is also highly dependent on the location of the installation and the climatic conditions in the region.

• In agricultural areas, due to pollen fallout from plants, photovoltaic (solar) panels need to be cleaned at least twice a year.
• Photovoltaic (solar) panels that are located in areas with a high bird population or near transport facilities necessarily need to be cleaned more frequently.
• In urban areas, cleaning PV (solar) panels twice a year should be sufficient.
• For installations in industrial areas and in areas with a high degree of air pollution, the condition of the panels should be monitored and cleaning should be carried out as necessary.

Our company provides, among other services, panel cleaning. Do not hesitate to contact us, we will be happy to create a quote for you.