How essential is it to clean modules?

How essential is it to clean modules?

impact of dust on solar panels

In 2015, iEnergytech conducted performance measurements on solar strings at a residence to determine the effect of dust that had settled on the modules. IV tests were carried out using high-accuracy IV testers; the tests had to be done at the right time when the Sun was high in the sky (to simulate standard test conditions).

These modules were installed on a flat roof, pitched at 26 degrees facing north—in Heathmont, Victoria; some construction was happening in the neighbourhood causing dust to rise and some of it was settling on the modules leaving a film of dust. In addition there were some bird droppings.

Measurements were taken at a module level and string level, before and after cleaning the modules. The performance improvement was found to be 3%. Note that in carrying out the tests, the IV set up took into account air mass and cell temperature to bring the test conditions to a base line of the Standard Test Conditions (STC).

Location: Heathmont, Melbourne, Vic, 2015; System size 4.38kWp