Sharp Contrast in Solar Power Generation Amounts on 2 Islands (page 4)
Panels inspected on-site
Damaged panels tested by 'PV test car'
At the mega-solar plants on Ukishima and Ohgishima, solar panel conditions were recently investigated on-site. Targeting the solar panels which had been found to be damaged through a visual inspection, I-V (current-voltage) characteristics were measured and an electroluminescence (EL) test was also carried out (Fig. 4).
These two tests were contracted to Adler Solar Works Co Ltd (Yokohama City) of the Yokohama Kankyo Design Co Ltd (Yokohama City) Group. This company is engaged in operation and maintenance (O&M) services and technical due diligence of solar power plants.
The on-site I-V characteristic measurement and EL test were implemented using a "PV test car" made in Germany. To measure I-V characteristics, the car evaluates output characteristics by string. In the EL test, it assesses the presence and state of micro cracks in the cells (power generation elements) of solar panels.
The major purpose of this inspection at the mega-solar plants on Ukishima and Ohgishima was to confirm how the micro cracks in the cells were affecting power output. At the mega-solar plant on Ohgishima, how far the dirty cover glass of solar panels affected output was also verified. Output was measured before and after cleaning the solar panels.
TEPCO HD will leverage these inspection results as the data for optimal mega-solar operation from now.