Evaluation of System Losses for 48V and 380V Solar Powered LVDC Microgrids

International Energy Agency estimates that 1 billion people worldwide have no access to electricity. Commonly prevalent offgrid electrification strategies through a) standalone solar and b) low-power central microgrids are largely suboptimal or prohibitively high cost for services beyond basic electrification (light services and mobile phone charging). Distributed solar generation, distributed storage architecture (DGDSA) for DC microgrids with peer-to-peer electricity sharing is now widely reported as an optimized architecture from systems efficiency perspective with allowance of higher power delivery through resource aggregation. However, DGDSA at distribution voltage of 48V or 380V may have significantly varying effiencies based on the spatial distribution of village houses for any offgrid electrification scheme. In this work, we evaluate both 380V and 48V distribution for low voltage (LV) DC microgrids incorporating a) converter efficiency and b) distribution efficiency for a typical village deployment in an offgrid scenario. System level efficiency is evaluated for peer to peer power sharing with varying inter-house distance. Results show that for power sharing of 100W, 48V distribution grid is an optimized choice for inter-house distance of up to 100m for a standard 4mm
²
conductor. For larger power sharing and higher inter-house distance, 380V grid becomes a more efficient choice.