Commencement Of Hydrogen Mixed Diesel Generator Operation To Enable Power Generation During A Power Outage, As Part Of The Demonstration To Establish Low Carbon Hydrogen Supply Chain In Tomiya City, Miyagi Prefecture
Hitachi, Ltd., Marubeni Corporation, Miyagi Consumer’s Co-operative Society and Tomiya City, Miyagi Prefecture conducted the Demonstration to Establish Low Carbon Hydrogen Supply Chain in Tomiya City, Miyagi Prefecture which was selected by the Japanese Ministry of the Environment as an “FY2017 Low Carbon Hydrogen Technology Demonstration Project in Cooperation with Local Government.” On this occasion, a Hydrogen Mixed Diesel Generator (hereinafter, the “HDMG”), which enables power generation even in the event of a power outage, was installed and operation of the HDMG commenced as part of an additional demonstration.
In the Demonstration, hydrogen generated by solar power and electrolysis was stored in the form of cassettes containing metal hydride* and delivered through Miyagi COOP’s existing distribution network to the homes of three families (registered as members of Miyagi COOP), Miyagi COOP supermarkets, and an Afterschool Children’s Club in Tomiya City. After delivery, the cassettes were attached to pure hydrogen fuel cells and the hydrogen was converted to power and heat. As a result of the Demonstration, which was carried out over a three year period, an 0.8ton reduction of CO2 emissions per home was achieved, which was one of the targets for the Demonstration. Additionally, operation data of the facilities was obtained.
Power generation by renewable energy, such as solar power, fluctuates depending on weather conditions. Therefore, as it is important to be able to provide a stable supply of electricity, a method of converting the surplus electricity into storable hydrogen that does not emit CO2 has been garnering attention. On the other hand, in the event of a power outage due to a disaster, building a supply chain that operates facilities sustainably, while making maximum use of hydrogen to prevent climate change, is necessary to support BCP.
In this additional demonstration, HDMG jointly developed by Hitachi and Denyo Co., Ltd. was installed at the logistics center of Miyagi COOP with the aim of utilizing hydrogen more than ever before and generating power for self-consumption. The HDMG strengthens BCP compliance by mixing hydrogen with SVO*3 and light oil in a variable ratio and generating electricity with a diesel engine generator. This is an advanced attempt to co-fire with hydrogen using SVO produced from the Miyagi COOP store side dish department. Results of the demonstration are expected to be obtained by end of March 2021.
With the installation of the HDMG, it will be possible to generate electricity with the stored hydrogen and SVO even in the event of a power outage due to a disaster that affects a broad area. After restarting the electrolyzer and auxiliary equipment with power from HDMG, if the power from the photovoltaic power generation system is available, continuous hydrogen production will be possible, and the cassettes will be delivered by Miyagi COOP.
In addition, the hydrogen purity used in the HDMG is not necessary for the hydrogen purity required for fuel cells; the HDMG can generate power with only heavy oil or light oil, without hydrogen, and increasing the co-firing rate of hydrogen improves power generation efficiency. With the use of SVO, it is expected that the effective use of waste liquid will be realized, and the SVO ratio can be connected to the grid under the Feed-in Tariff Scheme for Renewable Energy (‘FIT’).
Hitachi, Marubeni, Miyagi COOP and Tomiya City will promote the nationwide expansion of the supply chain, starting with establishment in Tomiya City, which announced its commitment to net zero carbon emissions by 2050 on February 10, 2021, and will continue to rollout access across Miyagi prefecture, the Tohoku region, and then to all other areas of Japan. The goal is a future society with zero carbon dioxide emissions.
- Metal Hydride: Alloy which reversibly absorbs hydrogen when temperature decreases or pressure increases, and desorbs when temperature increases or pressure decreases.
- BCP (Business Continuity Plan): The document which outlines how a business will continue operating during an unplanned disruption in service.
- SVO (Straight Vegetable Oil): Raw Vegetable oil (Waste cooking oil) which is removed impurities.
Hydrogen Mixed Diesel Generator
Base machine DCA-125LSIE
Length × Width × Height 2.650×1.080×1.600 m
Weight 2.290 t
Power Generation Capacity
Rated Output Three-phase AC output : 44kW
Power Conditioner Output : 40kW
Rated voltage / Phase /
frequency AC400V / Three-phase 4wire / 50Hz
Combustion Hydrogen Mixed
Combustion Ratio 50%（Calorie conversion with diesel fuel）
Hydrogen Flow Rate 350NL / min