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Thoughts on Energy Storage

Published on Oct. 5, 2016: The Denki Shimbun (The Electric Daily News)
Shojiro Matsuura
President & CEO

There have been several media reports indicating that a decision on the political level is imminent concerning the future of the prototype fast-breeder reactor ‘Monju’ development program. There is no question that those who have ever been involved in nuclear energy’s research, development and utilization in Japan are concerned about this situation. However, on the surface at least, heated debate among those people has not appeared. They seem to be refraining from candid discussions in view of the complexity and gravity of the issue’s background and history.

In the given situation, it is wiser to conduct a multi-faceted re-examination of the ‘current and future significance of Japan’s nuclear research, development and utilization,’ even if that may look like a roundabout approach. The task of fundamental importance is to explore systems in which energies, required by the nation’s current and future society, can be provided in view of various factors such as convenience, safety, indefinite supply stability and economy.

There is no choice but to obtain energies from nature. Specific energy sources include water (rivers, oceans, geothermal energy), wind, solar power, plant-based energy, fossil fuels, biological oil/fat, manpower, animal power and nuclear materials.

Of these options, renewable energies and ocean-dissolved nuclear materials have minimal disparity under a populated environment and are unlikely to be a case of dispute geopolitically. Building and utilizing a system that combines them optimally to the maximum extent, could mitigate a race for attaining other resources.

The mass use of energies mostly occurs when they are used as the source of power, heat or light. In today’s world, miscellaneous energies can be converted into electric energy (power) as secondary energy to be used in any applications. The range of energies that can be utilized has expanded from zero eV (electron volt) to peta eV. The ability to convert energies into electricity that can be freely regulated, was one of the key factors that have brought about modern civilization.

However, the major weakness in electricity use is the lack of ability to store a large amount of electricity for later use. Chemical batteries and capacitance may be used to store some electricity, but it is unfathomable, with today’s technology, to store the amount of electricity that a large power station generates over several years.

Meanwhile, with regard to renewable energies, it is essentially impossible to avoid output fluctuations caused by diurnal rhythm and extended period of time, or shield their facilities from natural disasters. Such energies must be stored in batteries and regulated for use if they are to be used as stable, high-quality electricity. Even if a large-capacity battery or power storage equipment should be developed, the scale of its short circuit accident would be unimaginable.

Some natural phenomena, such as typhoons, rainstorms, mega earthquakes and crash of large meteorites, involve energy accumulation of a scale beyond imagination. Their energy accumulation results from spatial movements of materials. Another mechanism of natural energy conversion converts mass into energy.

Nuclear materials have mass or energy accumulated within their nuclear structure with nuclear force. Today’s science and technology have made it possible to extract energies, accumulated within the nucleus through nuclear fission.

Nuclear materials not undergoing nuclear reaction are extremely stable. In other words, nuclear materials are like batteries that store an extremely large amount of energy safely and stably for an extended period of time.

This perspective should be revisited in adopting the policy of long-term nuclear research, development and utilization on the premise of safety assurance. The government policy on the Monju issue should be determined rationally based on this basic perspective, and also in view of various conditions in today’s society, with options including freezing the program.




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