The Public Utility Systems Group offers an extensive range of products and services used in public utilities and transportation to governments, highway and railway operators, and a host of other companies involved in social infrastructure. These solutions include water treatment plant systems, intelligent transport systems, railway information systems, and electromagnetic products for rolling stock. Our aim is to manufacture products that are smaller, weigh less, provide better performance, and operate with higher efficiency, thereby reducing environmental impact by consuming fewer resources and using less electricity. In recent years, we have also placed a focus on next-generation infrastructure. Our efforts include introducing solutions to fully optimize the energy used by railways, energy-saving business related to water treatment processes, and initiatives for the smart community business. At the Kobe Works, Itami Works, Nagasaki Works, and our affiliates, where operations include designing and manufacturing products and systems, energy consumption has been reduced by introducing improvements in areas like facilities, testing, and distribution. Initiatives have also been implemented to prevent soil and water pollution and to reduce and control the waste products generated during manufacture, including carefully managing the toxic substances used in painting facilities.
Senior Vice President
In Charge of Public Utility Systems Group
The Public Utility Systems Group provides a host of products that serve a vital, long-term role in social infrastructure, including water treatment facilities, roadways, and rolling stock. As a part of this, while ensuring high quality and functionality in design and manufacturing, we continue to promote the use of fewer resources and less power by pursuing smaller size, lighter weight, greater efficiency, and higher performance as the basis for our aim to realize a low-carbon society.
In recent years, we have seen heightened expectations toward the development of next-generation social infrastructure that makes full use of renewable energies and information and communication technologies (ICT), which supports greater power supply efficiency and optimization. In response, we are working on total energy and environmental solutions for railways.
This involves not only the train itself, which consumes the most energy, but also involves the use of IoT*1 and new energy management technologies allowing energy creation and storage at stations, vehicle bases, and across the whole network, with the goal of "total optimization of energy used by railways".
Among these activities, an inverter for rolling stock equipped with a large-capacity, all-SiC power module won the Ministry of Economy, Trade and Industry Minister's Award, the top prize of Excellence in Energy-Conservation Equipment Awards in fiscal 2016, as well as the Excellence Award of the Eco Products Awards and the Ichimura Industrial Award. In addition, the incorporation of hybrid SiC power modules in our Station Energy-Saving Inverter (S-EIV), which uses the surplus regenerative electric power that is generated when rolling stock are braking as a power source for station lighting and air conditioning, won the Agency for Natural Resources and Energy Director-General's Award in the New Energy Award in fiscal 2017. Moving forward, we will continue to work towards saving energy by expanding the applications of all-SiC power modules.
We have also been focusing on "energy conservation in water treatment processes" which involves wastewater treatment and the purification of plant wastewater. We are developing technologies to efficiently generate OH radicals*2 which can remove persistent organic substances from wastewater, something that is difficult to achieve with conventional technology, to enable efficient water treatment through a simple system. We have also developed a water processing technique that uses a membrane bioreactor (EcoMBR)*3 to clean the membrane filters for treating and recycling municipal and industrial wastewater with ozonated water, enabling it to treat twice as much water per membrane filter surface area as conventional methods. Furthermore, the Public Utility Systems Group is expanding its activities outside of Japan, conducting demonstrations and testing in China and Singapore.
Going forward, we will contribute to the realization of a safe, secure, and comfortable society by making full use of the wide ranging technologies that we have developed over the years, as well as ongoing technological development.
With our commitment to the total optimization of energy used by railways, we are helping to realize the vision of a low-carbon society.
Application of large-capacity all-SiC power module
Inverter for rolling stock
We produced an inverter equipped with all-SiC power modules for use in rolling stock and launched it at the end of fiscal 2015. It enables energy savings of approximately 40% compared to conventional vehicles. This product is now being used by many customers.
We have produced and introduced to the market a station auxiliary power system that is capable of supplying the regenerative electric power generated when rolling stock is braking directly to a station's electrical facilities (lights, air conditioners, elevators, etc.). Each station where the system is installed saves approximately 600 kWh per day (equivalent to the electricity used by 60 households). This is contributing to energy saving at station buildings. Furthermore, in September 2016, we introduced to market a hybrid version that is smaller than conventional models and combines a storage battery with the power system.
We have developed an optimal power supply control system that utilizes ICT to control the voltage of overhead power lines based on the operational status of railcars. The system transmits real-time information on the position of railcars and train operation through information communication networks. Upon receiving information, a management system organically controls substation outputs, S-EIV and power storage systems. The system is designed to minimize energy consumed throughout the route.
Railcar air-conditioning unit
In addition to introducing smaller-diameter piping and achieving a 20% reduction in heat exchanger size, we have readjusted materials to reduce the weight by 6%, thereby enabling the production of a more compact, lighter air-conditioning system. Additionally, our aim is to reduce environmental impact by promoting the use of an alternate refrigerant with low GWP* in place of greenhouse gases.
Ozone generators are used in advanced water treatment processes and paper pulp bleaching because of their superior oxidation and ability to eliminate bacteria, odors, and colors. By developing a technology that places electrodes closer together in the generator's oxygen source and also applying it to the air source, we have achieved a more compact and more efficient design. As a result, overall system power consumption has been reduced 15%.
We have developed a novel water treatment technology using gas/liquid interfacial discharge to generate OH radicals, which are used to treat persistent organic substances in wastewater, enabling water to be treated with a simplified system. By applying an electrical discharge process directly to wastewater flowing along an inclined surface, OH radicals are generated at the gas-liquid interface --the boundary between liquid and gas --and in the gas and liquids themselves, thus enabling efficient water treatment. The introduction of this technology can realize a two-fold increase in the energy efficiency of water treatment compared to traditional methods.
We have developed a water treatment technology using an immersion-type membrane separation bioreactor (EcoMBR) which uses ozonized water to clean the membrane filters for treating and recycling municipal and industrial wastewater. The EcoMBR system is compact and energy-efficient, and is capable of high-speed filtration, which enables the device to treat twice as much water per membrane filter surface area compared to conventional methods.
We have developed a function that enables optimal energy supply by predicting power demand—based on factors such as past usage results and weather forecasts—and combining power sources like commercial power, solar power, wind power, and storage batteries, and we delivered such a system to Satsuma Sendai City, Kagoshima Prefecture in fiscal 2016. Moving forward, this system will be incorporated into various systems, such as building management and water treatment systems, with the goal of putting smart energy systems to practical use in a wide range of areas.
By increasing the efficiency of the power and drive circuit for the LED drive, optimizing the drive voltage, and introducing a high-efficiency LED, we have reduced power consumption per unit of area by 3%. In addition, by reviewing the housing structure, we have reduced the screen weight by 40%.
Initiatives to reduce environmental impact such as through activities to improve facilities, testing and distribution and the enforcement of thorough waste separation, continue on a daily basis at Kobe Works, Itami Works, and Nagasaki Works, which function as our product supply bases.
New lines built at the Kobe Works and Itami Works employ LED lighting, higher efficiency air conditioners, and solar power generation systems to achieve greater power savings. We are also making improvements that contribute to increasing facility efficiency, such as utilizing the exhaust from thermal-catalyst boilers (the heat source for drying ovens) to heat water to wash products.
In the testing of large electric power devices such as VVVF* equipment for rolling stock, we are implementing initiatives to effectively utilize energy, including the use of electricity generated by power generators connected as artifical loads, thus achieving zero waste.
We are promoting the reduction of CO2 emissions by expanding the use of returnable packaging and making a modal shift in transportation, from using trucks and planes to using railways and ships.
In response to growing railway demand overseas, we have set up new overseas sites in India and Poland as an addition to our existing sites in North America, Mexico and Italy. In anticipation of a further increase in demand in Europe, the United States and Asia against the backdrop of global warming, we will continue to strengthen and expand our overseas production bases. We will also promote local production and the provision of services for local consumption in order to reduce CO2 produced during transportation.