Self Cleaning Solar Panels | Green Energy News

June 6, 2004 – Vol.9 No.11

SELF-CLEANING SOLAR PANELS.

Dirty glass blocks sunlight. Whether the glass is in a window or as weather proofing for a solar energy system, glass that is covered with dirt and grime won’t allow as many photons through as clean glass will. Even small amounts of dust will hamper light transmission and thus solar performance.

Cleaning is considered one of the few maintenance tasks for solar systems. While rain is often relied upon to clean hard-to-access solar systems, rain is also dirty and can’t be relied upon as a cleaning agent.

(Rain drops are formed when water vapor in the air condenses around tiny dust and pollution particles or ice crystals, which is why your just-cleaned car gets dirty again as soon as it rains.)

Now, if solar panel companies adopt a new glass technology, the need to clean solar panels may be coming to an end.

Pilkington, a U.K. glass manufacturer, has invented a self-cleaning glass known as Pilkington Activ. The company uses a thin (15 nanometer) coating of titanium dioxide on the glass which when hit by ultraviolet radiation in sunlight creates a photocatalytic effect. This, in turn, will break down organic matter, such as bird droppings, pollen or tree sap.

Further the coating aids in helping rainwater (or water from a hose) clean the glass of inorganic dirt like cement dust. The titanium dioxide coating makes the surface of the glass hydrophilic. That is, water won’t bead up on the glass, it will form sheets. Since droplets are avoided on the glass dirt and dust will wash away easily and the glass won’t spot or streak. (Even if it doesn’t rain a quick hose-down will suffice.)

Though Pilkington Activ was designed for use in windows, there doesn’t seem to be any reason it couldn’t be used with solar technologies as well. The company mentions increased energy efficiency with the product. Any solar energy application would benefit - solar photovoltaic, solar thermal systems, even passive solar applications: Clean glass will let more sunlight stream into a room keeping it toasty on a cold winter’s day. Visit Activglass at http://www.activglass.com/