In the decade since the 2011 East Japan Earthquake and Tsunami, microgrids have sprung up across Japan to help the country meet their energy demands and build resilience.
On March 11, 2011, a magnitude 9.0 earthquake struck Japan—the largest ever experienced and so powerful that it shifted the Earth on its axis by 10 cm! The Tōhoku earthquake triggered a series of tsunamis with waves as tall as 10 meters that surged nearly 5 km over the land, causing massive destruction. Following the earthquake, a 15-meter tsunami knocked out both the power supply and the cooling mechanisms of the three Fukushima Daiichi nuclear reactors and all three cores melted a few days after.
March 11 is now a national day of remembrance. The earthquake highlighted an important lesson: the country’s need to rebuild cities as ‘smart cities’ or risk another catastrophic disaster. To this end, Japan established the National Resilience Program with the goal of building in back-up power capabilities. The National Resilience Program led to the development of several microgrids—thanks to their inherent flexibility and potential to provide backup power—with the first microgrid community established in Higashimatsushima.
Located in the Miyagi Prefecture, Higashimatsushima was one of the hardest-hit cities but has since become a good example of an ‘EcoTown’ that is stronger and more resilient to climate change and natural disasters. It is also home to the Sendai 3/11 Memorial Community Center. The Center, which opened in 2016, has exhibits showing impacts of the tsunami on local coastal areas as well as progress on reconstruction and restoration. The Center acts both as an educational exhibit but also as a place for the community to gather with frequent events that enable residents and visitors to share memories and information, and build connections.
Roughly 70% of Higashimatsushima was destroyed in the 2011 disaster—the greatest damage of any city in Japan. More than 15,000 people were evacuated and over 1,100 perished. It also took several months to restore power, which led to food shortages and communication lines being cut, preventing people from reaching evacuation centers or contacting their loved ones. The power took over five months to restore in some parts of the city.
Following the tsunami, the residents began to look for ways to rebuild the city and ensure they would be prepared for future disasters, including having access to a guaranteed energy supply. The event fundamentally changed the way policymakers began to think about building smart cities, with a focus on vulnerabilities to potential flooding and sea level rise, and the need to develop robust energy systems capable of backup generation.
Japan’s changing energy mix
Prior to 2011, around 30% of Japan’s electricity came from nuclear sources, and this percentage was expected to increase. However, due to the disaster, there was an almost immediate change in the energy sources, as all the country’s nuclear reactors were initially shut down, with only a few remaining in use. The meltdown at Fukushima served to discredit nuclear energy and greatly incentivized renewable energy, which increased from less than 10% in 2011 to 23% in 2020 and is projected to increase to 25% by 2030. Additionally, Japan’s national energy system was completely restructured: instead of relying on the ten energy companies that held a monopoly at the time, local cities and communities could begin their own power initiatives. Higashimatsushima is a particularly interesting case study because of how quickly the city worked to move from reliance on nuclear to scaling up renewable energy sources. In the five years from 2011 to 2016, the city increased renewable energy by over twenty times, from 800kW to over 15000kW.
Local energy independence
From solar, wind, and biomass, Higashimatsushima is currently exploring new ways to increase renewable energy. For example, the local Senseki hospital lost power during the wake of the earthquake and had to rely on a backup generator that reduced available energy supply. This was yet another difficult lesson as it became clear that without reliable backup energy, some of the more serious patients had to be transferred to other hospitals that still had power. While the power was restored in five days, it became clear that patients were at risk of dying. Thus, the hospital decided to turn to another solution—the Higashimatsushima Disaster Prepared Smart EcoTown—to become more resilient in the future. Powered by solar energy, the EcoTown has its own community microgrid—one of Japan’s first—with seventy houses, fifteen apartments, and four hospitals. The system generates and stores the solar energy in a microgrid, which is controlled by a community management system, and stored in a massive battery. If another natural disaster hits the area, the Higashimatsushima EcoTown would still be able to generate energy from the solar panels and battery power for at least three days. In total, the town produces 50% of the energy it needs, with the remaining 50% purchased from the traditional grid. Importantly, the EcoTown is owned and managed by the city of Higashimatsushima, which became possible because of energy deregulation in 2016.
Local ownership, local management
Higashimatsushima Organization for Progress, Economy, Education and Energy (HOPE) manages EcoTown and other regeneration projects in the area. One of the key issues that drives the smart city is that the energy produced is all locally managed, rather than being managed by a large company, so the community controls their own destiny.
Building energy and climate resilience
Besides the solar microgrid, a tidal embankment was constructed from the tsunami debris and serves as a barrier to help ensure the city’s resilience. There is also the new Kizuna solar park with nearly 15000 solar panels, or about 2 MW per year—enough to fuel 600 houses for a year! By taking a holistic approach to enhancing the city’s climate and energy resilience and focusing on empowering local communities, Higashimatsushima is an incredible model of how to effectively rebuild in the wake of a disaster. Recently, other surrounding districts in Higashimatsushima are also being rebuilt with a focus on disaster-preventive resilience and energy independence. These new bottom-up, community focused EcoTowns may serve as a model for building more resilient communities across Japan and globally, from energy independence, natural disaster resilience, and resilience of the community itself as a cohesive, inclusive social body.
Image credit: Construction 21