Smart-Cities Look to Fix Japan's Broken-Up Grid with Microgrids

Post-Fukushima, better safe than sorry.

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Feb 21 2015, 12:00pm

​​Image: Joshua Heyer

​Grids make sense. They really do. The notion, popular enough among techno-libertarian types, that every single power-consuming unit (house, factory, bunker) might be better off generating its own power off-the-grid is mostly absurd. Some things make sense (are more efficient) to do together, particularly when those things are more or less consumed in the same ways by basically everyone. Like electricity.

But maybe there's something in between. Enter microgrids. ​​As detailed on IEEE Spectrum's grid blog, post-Fukushima Japan has seen a boom in the development of relatively small-scale localized grids. At first, the point was largely to boost grid efficiency, but the focus has grown more and more to include local power generation. This has residential applications, but one of the strongest examples is Toyota's F-Grid.

Image: Toyota

The result of a 2013 partnership between the car manufacturer's Miyagi Prefecture factories and other neighboring industrial power consumers, it's first a supplementary grid, a backup power source and then some. Toyota's plant was knocked offline for two weeks following the Fukushima disaster, in some part the result of relying on only one power provider, Tohoku Electric Power Co. That's a long time.

​The point of F-Grid is twofold:

F-Grid LLP optimally combines the electricity from an electric power company, co-generation, and solar power generation to realize clean, economical and sustainable power supply over the industrial area

In emergency situations, supply electricity to the neighboring community area covering the Ohira village office, which functions as a disaster-management facility.

A partnership between Honda and the Japanese homebuilder Sekisui House is pushing the same idea into the residential realm with a new smarthome system. As with F-Grid, the point isn't so much to go off-grid as it is to guarantee consistent supply.

The plan isn't fucking around either: every house comes with solar panels, a gas generator, home-scale battery, and electric car. Everything is linked together and planned by a unit called "Smart-e Mix Manager." Usually, the home draws from the macrogrid like usual, but in the event of an emergency, each one will have a charged battery and more than enough capability to keep it topped-off through the outage.

Meanwhile, the idea is scaling up to whole smart-cities, as is the case with Kashiwanoha. The development on the outskirts of Tokyo gets most of its power from the macrogrid, but keeps a bank of batteries charged with help from arrays of rooftop solar panels. Having the ability to store power gives the city the ability to buy its electricity from the macrogrid mostly at night, when prices are down.

Of course, that last bit depends on being a smart-city surrounded by dumb cities and if the mass-storage idea scales outward, we can imagine the outcome being energy prices that just stop fluctuating. Still: clever ideas.

They are, however, clever ideas mostly suited for Japan, which has a rather unusual grid system. Unlike North America, where power can be shared across very large distances and drawn from a wide variety of sources, ​Japan has a partitioned grid. It's a small place already (relative to North America), but Japan's power network is broken up into different zones by varying transmission frequencies. This limits sharing and is a big contributor to the outages that led to the strategies above in the first place. So: microgrids here are solving the problems, of well, microgrids.