Research Article

Reduction of Soiling on Photovoltaic Modules by a Tracker System with Downward-Facing Standby State

Figure 7

Relationship between the accumulated rainfall during the standby state for each measurement interval (accumulated for two weeks before each measurement) () and the difference in transmittance of the substrates on the downward and upward systems () for (a) PMMA and (b) glass.
(a)
(b)