Yokohama Smart City Project Demonstrates Experimental Social Infrastructure

Yokohama Smart City Project Demonstrates Experimental Social Infrastructure

By Ryan Franks, Program Manager, NEMA

Today the White House is hosting an Earthquake Resilience Summit to “promote adoption of an earthquake early warning system in the United States.” Electrical manufacturers recognize the vital importance of smart infrastructure—and smart rebuilding—to mitigate the effects of natural disasters and ensure quicker and more effective recovery. This article, published in September 2013, details a smart infrastructure project undertaken in Yokohama, Japan, that serves as a model for demonstrating the importance and effectiveness of safeguarding the resiliency and efficiency of power grids.

Yokokhama, Japan

It is estimated that by 2050 64.1 percent of the developing world and 85.9 percent of the developed world will be urbanized[1]. In some locations, organic growth and renovations will take place as populations move from rural areas to cities. In others, a more planned approach to growth will occur by way of the concept of “smart cities.”

In July 2013, I had the opportunity to visit and tour the Yokohama Smart City Project (YSCP) in Japan, one of four such communities planned in that country. In a smart city, energy, water, public health, safety, transportation, and even governance are managed collectively by gathering, analyzing, and acting on data to create a community where efficiency, safety, and wellbeing are enhanced. The management of electricity by the smart grid is the most advanced characteristic of the city and will serve as a model for the intelligent operation of other services.

According to the Japanese Smart City Portal[2], “YSCP aim[s] to build a smart city having the ability to support the mass introduction of renewable energy as well as to ensure the stable energy supply across the municipal area even in time of crisis.”

The catastrophic Great East Japan Earthquake in March 2011 and associated tsunami and nuclear power plant shutdowns have increased the country’s focus on the resiliency and efficiency of communities and their power grids.

YSCP figureYSCP is perhaps best described as a microgrid retrofit to existing infrastructure, as shown abstractly in the figure above. Importantly, these facilities are not placed near one another, but are located at disparate points in Yokohama. A cluster energy management system (CEMS) communicates with electric vehicle (EV) infrastructure at residences, home energy management systems, factory energy management systems, and aggregated commercial and residential building energy management systems (BEMS).

CEMS manage the generation, storage, and use of electricity throughout the connected system.

Generation of electricity and heat, as well as cooling, are done onsite at participating facilities using solar photovoltaics, thermal panels, and adsorption chillers; micro cogeneration from natural gas; and air-cooled chiller pumps and heat pumps.

Electricity is stored in Toshiba SCiB™ systems using lithium ion batteries; thermal energy is stored in systems using paraffin wax. Storage is utilized for both, reducing peak consumption from the electricity grid via peak shaving and ensuring energy security should the electricity grid be disrupted.

Forecasting Optimizes Operations

BEMS predict energy usage a day in advance and plan the optimized operation of buildings based on forecasted usage and occupancy data. Sections of office buildings encourage the smart use of electricity and energy through two mechanisms: direct current (dc) distribution and detection sensors. Office components, including computers, monitors, task lighting, and overhead LED lighting, are wired directly to a dc distribution system, which removes inefficiencies involved in converting alternating current electricity to dc electricity. Moreover, each workspace and area is equipped with a motion sensor that turns off lighting and puts other services to sleep when the location is unoccupied. This occupancy data is then relayed to a zoning system to provide occupancy patterns for analysis in the BEMS.

The purpose of this project is to gain knowledge about best practices for the smart management and consumption of energy in the overall context of creating smart cities. More than 30 companies including electronics suppliers, power equipment suppliers, building and real estate firms, and utilities came together to bring YSCP to fruition, demonstrating how large an undertaking infrastructure projects are. With the encouragement of cities and the Japanese Ministry of Economy, Trade, and Industry, these entities plan to create more smart cities and use that knowledge to expand the concepts of social infrastructure and pre-packaged infrastructure designs to other regions.


This article was originally published in the September 2013 issue of ei, the magazine of the electroindustry.

More resources:

Storm Reconstruction: Rebuild Smart

Evaluating Fire- and Heat-Damaged Electrical Equipment

Evaluating Water-Damaged Electrical Equipment

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