Driven by wind and solar photovoltaics technology, the power industry is shifting towards a distributed generation (DG) paradigm. We focus on DC micro-grid, and then extend to grid connected DG system. The current research on energy management will provide energy consumption optimization, reduce peak power and enable prioritized islanding, as well as create an opportunity for excess produced energy to be stored to battery or sold back to the grid. It will monitor and operate remotely and automatically, further reducing overall costs.