Pollution, bird droppings, traffic dust and airborne particles such as pollen all contribute to dirtifying an investment in solar panels, resulting in inefficient performance. Dirty panels mean a loss of power. This is because when debris and grime cover the solar array, this reduces the amount of sunlight reaching the solar cells-leading to a reduction in the electricity produced.
A solar panel is made up of modules of solar cells all wired and mounted together encased and placed in a protective glass layer. The cells are made using semiconductor materials such as silicon. Each cell has positive and negative poles and when sunlight hits the cell surface, it makes electrons in the semi-conductorproduce electrical energy. Dirty cells means less light absorption-hence less electricity generation. The potential loss of electrical energy depends on the filth levels on the panel. Experts and scientific studies have reported that the loss could be as high as 30 per cent.
There are two ways of checking if solar panels need cleaning. The first way is physical inspection. This entails inspecting the panels periodically, which will depend on manufacturer specifications and user location. Ordinarily, installing solar panels in dusty areas means more frequent inspection. The second way is using a monitoring service. For a monthly fee or a flat rate, these services diagnose and analyse the production capacity and compare this with the optimal system specifications. The monitoring system also reveals money and power and carbon emission savings. Some monitoring systems are accessible from the internet and smartphone devices. Monitoring systems make system performance and troubleshooting easier, though they may not be essential, especially for smaller solar panel systems
Owners of small solar systems may opt to do the solar panel cleaning by themselves. Just like cleaning windows, warm water and soap can be used to eliminate dirt and grime from the panels. However manual cleaning is fraught with risks. The cleaner can fall off and get injured and the water can damage the electrical systems of the panels. It is therefore better to leave the cleaning to professionals.
There are also cleaning robots that are designed to perform solar panel cleaning. These systems are attached to the solar panels and are programmed to automatically wash and rinse the solar panels.
Some large industrial, commercial or public utility solar panel systems employ self-cleaning solar panels. This technology entails covering the solar panels with electrically sensitive, transparent material or sheet. Dust levels on the surface panel are then monitored and when it reaches a critical level, the covering material is energised. An electrical charge then produces a wave that cascades over the material’s surface, shifting the dust to the edge.
One proven method of ensuring a cleaner solar panel is using hydrophobic coating on the panels. These coatings create a hard, smooth,anti-static surface that repels environmental pollutants such as sand, pollen and dust. Hydrophobic coating can be applied at any time during the production or installation of the solar panels.
A new technology has been developed that eliminates the need to clean solar panels. This involves using solar roof tiles to build houses and other buildings. These tiles are made using a thin film solar cell (called Building-integrated photo-voltaics or BIPV) that both acts as a roof and also produces electricity.