The power distribution network will be changed towards the future Smart Grid due to increased number of installed renewable power generation units to fulfill the tightened environmental regulation. It can be concluded that the control might be simpler and the grid operation more reliable if the AC grid would be replaced by DC grid. However, the detailed energy efficiency analysis of the DC grid is not thoroughly studied. The efficiency and total lifetime costs are the key parameters when the network owners consider the future grid structure. This book addresses the factors, which affect the energy efficiency of the low voltage DC (LVDC) distribution network from power electronics perspective.