Long-term field test of solar PV power generation using one-axis 3-position sun tracker

The 1 axis-3 position (1A-3P) sun tracking PV was built and tested to measure the daily and long-term power generation of the solar PV system. A comparative test using a fixed PV and a 1A-3P tracking PV was carried out with two identical stand-alone solar-powered LED lighting systems. The field test in the particular days shows that the 1A-3P tracking PV can generate 35.8% more electricity than the fixed PV in a partly-cloudy weather with daily-total solar irradiation HT = 11.7 MJ/m2 day, or 35.6% in clear weather with HT = 18.5 MJ/m2 day. This indicates that the present 1A-3P tracking PV can perform very close to a dual-axis continuous tracking PV (Kacira et al., 2004). The long-term outdoor test results have shown that the increase of daily power generation of 1A-3P tracking PV increases with increasing daily-total solar irradiation. The increase of monthly-total power generation for 1A-3P sun tracking PV is between 18.5–28.0%. The total power generation increase in the test period from March 1, 2010 to March 31, 2011, is 23.6% in Taipei (an area of low solar energy resource). The long-term performance of the present 1X-3P tracking PV is shown very close to the 1-axis continuous tracking PV in Taiwan (Chang, 2009). If the 1A-3P tracking PV is used in the area of high solar energy resource with yearly-average HT > 17 MJ/m2 day, the increase of total long-term power generation with respect to fixed PV will be higher than 37.5%. This is very close to that of dual-axis continuous tracking PV.The 1A-3P tracker can be easily mounted on the wall of a building. The cost of the whole tracker is about the same as the regular mounting cost of a conventional rooftop PV system. This means that there is no extra cost for 1A-3P PV mounted on buildings. The 1A-3P PV is quite suitable for building-integrated applications.

► The present study carried out outdoor experiments to measure the daily-total and long-term PV energy generation of the 1A-3P tracking PV and the fixed PV simultaneously.
► The test in the particular days shows that the 1A-3P performs very close to 2-axis continuous tracking PV.
► The daily-total performance of 1X-3P tracking PV is very close to 1-axis continuous tracking PV.
► The long-term test for 13 months shows that 1A-3P tracking PV generates 23.6% more energy than the fixed PV in Taipei.
► If 1A-3P tracking PV is used in high irradiation area, the long-term energy generation will be very close to 2-axis continuous tracking PV.