A concept of an Internet-like electric power system, which connects and controls small-scale power grids through routers, has emerged in Japan. The envisaged system is called the Digital Grid, whose concept was developed by Professor Rikiya Abe of the University of Tokyo. With the aim of transforming the concept into reality, the Digital Grid Consortium launched its full-fledged operation on December 12.
The Digital Grid consists of multiple single units called cells, each of which has energy storage equipment and is capable of self-sustained operation. Cells can be of various sizes from a household to a region, and are connected to Digital Grid Routers (DGRs) set up on the grid. Through DGRs that are assigned unique addresses, the system exchanges electricity freely between cells or with the trunk transmission power system. Abe explained the system at a news conference and said, “In contrast to the concept of smart grid, which only exchanges information, the Digital Grid actually exchanges electricity.”
The Digital Grid Consortium, chaired by Abe, will initially work on the development of system specifications and other details jointly with three Japanese companies including NEC Corporation. Starting next fiscal year, it plans to develop a prototype of a cell-to-cell power interchange system as well as a residential system equipped with power storage. The US-based Electric Power Research Institute (EPRI) is also participating in the consortium as an advisor, and demonstration tests are planned at EPRI’s facilities to pursue international standardization of the Digital Grid.
