Evolving our electricity systems from the bottom up

The conceptual framework of the “Smart Grid” naturally takes the viewpoint of the grid, then works down into the details of its individual components. This is good and necessary, but there is an alternative approach that can complement and strengthen the “macrogrid” — to start from (very) small “nanogrids”. Nanogrids can be interconnected and aggregated into microgrids, and ultimately, through the meter, to the macrogrid. Nanogrids are already common today, in the form of USB-powered devices off a PC, Power over Ethernet distribution systems, and the electricity systems in cars and other vehicles. In addition, an increasing number of developing nation households have a nanogrid with local generation and battery storage. This paper defines nanogrids, delves into their existing and potential characteristics, and proposes some principles for standard interfaces between nanogrids and with microgrids.