Grid-interfaced urban domestic power pack

Grid-interfaced SPV power pack (GISPP) for urban domestic/commercial applications in developing countries has been proposed. The target market is the replacement of the existing grid-interfaced emergency power pack or (GIEPP) small petrol/diesel generators. The significant enhancement of the electricity bill due to the incorporation of the GIEPP is pointed out and a techno-economic analysis is carried out to estimate the payback period of the proposed GISPP. The hardware of a typical GISPP is designed using discrete logic controlling circuitry and on the other hand also with embedded controller and pulse width modulation technique so that the total battery charging current remains constant at the set value (usually at 10-hr. rate) and depending upon the maximum available SPV current, the requisite balance current is drawn from the grid supply. A methodology is also proposed for optimal sizing of the SPV system for the GISPP application to achieve the minimum payback period.