Performance of photovoltaic micro utility systems

Photovoltaic micro utility (MU) systems introduced in the rural areas of Bangladesh in 1999 currently number more than 10,000 systems. This paper presents the details and results of component and system performance of 35 MU systems installed by Grameen Shakti in 7 districts of Bangladesh through survey and performance studies. 50 Wp was the most common system size. The average overall efficiency of PV MU systems was 5.4%. The performances of battery and charge controller were also investigated and found to be satisfactory. The actual energy obtained by the users was also very close to the design values though the batteries were slightly oversized for lower capacity systems. The degradation of panel performance was not significant with age. The payback period of these systems were between 4.2 and 6.28 years, and the levelized electricity cost of PV MU systems was estimated to be 70 BDT (~ 0.85 $)/kWh. Users observed that after installing the PV MU systems, their communication with customers and suppliers improved, as well as their comfort. Furthermore, these systems also contributed to reduction of emissions and indoor air pollution.