Mitsubishi Heavy Industries Technical Review Vol. 58 No. 3 (September 2021)
1Market Introduction Status of Fuel Cell System"MEGAMIE®" and Future Efforts

KAZUO TOMIDA *1

MASANORI NISHIURA *1

HIROYUKI OZAWA*1

MASAHIRO MIHARA*1

TSUKASA YAMANE*1

NORIHISA MATAKE*2

Toward the realization of a carbon-free society by 2050, we are developing a system thatuses a solid oxide fuel cell (SOFC), which can generate electricity with high efficiency.
SOFC-MGT (Micro Gas Turbine) hybrid systems have been introduced to the market after thedemonstration of a 250 kW class system and are scheduled to be delivered to Gas- undWärme-Institut Essen e.V. (GWI) in Germany in fiscal 2021 for the first time for overseas
installation, following deliveries to the Marunouchi building of Mitsubishi Estate Co., Ltd., theTechnical Research Institute of Hazama Ando Corporation (hydrogen utilization) and the Ibaraki
Plant of Asahi Breweries, LTD (biogas utilization). We are also proceeding with the developmentof MW class systems that apply MGT by reflecting the elemental technology in the integrated coalgasification fuel cell combined cycle (IGFC) for the Osaki CoolGen Project. We are also
promoting the development of an improved system that uses a turbocharger (TC) as an air supply
source instead of the MGT. The TC system uses a cascade system, which combines SOFCs in twostages and is expected to improve partial load efficiency. The demonstration tests are scheduled tobe conducted in 2021.

|1. Introduction
To curb global warming and realize a sustainable global environment, countries have set
ambitious goals to rapidly shift to an energy system for decarbonization and are accelerating themovement to promote decarbonization as a strategic industrial policy. Japan has also declared its
aim to realize a carbon-neutral, carbon-free society by 2050. In order to realize a carbon-freesociety, it is necessary to establish an appropriate energy mix by introducing highly-efficient
distributed power sources and renewable energy into the advanced power grid constructed bylarge-scale centralized power sources, while ensuring safety, supply stability, economy andenvironmental friendliness. In order to establish the energy mix, it is effective to combine CCS(Carbon dioxide Capture and Storage) as a CO2 capture and storage technology and CCUS
(Carbon dioxide Capture, Utilization and Storage) that uses the captured and stored CO2, inaddition to converting the surplus electricity of renewable energy to hydrogen by P2G (Power toGas) or operate it in combination with electricity storage, instead of suppressing it. Since thedemand for power supply security has been increasing due to the frequent occurrence of disasters
such as typhoons and torrential rains in recent years—in addition to earthquakes—it is also
important to secure BCP (Business continuity plan) and power resilience.
Mitsubishi Power, Ltd. (Mitsubishi Power) is developing the "MEGAMIE" commercial
industrial fuel cell system that uses SOFC (Solid Oxide Fuel Cell). SOFC can also electrolyze
steam to generate hydrogen by reverse operation and is positioned as an effective application for
the realization of a carbon-free society. We are currently promoting the introduction of 250 kW
class SOFC-MGT hybrid systems to the market and the development of a TC system that isexpected to improve operability through features such as higher partial load efficiency. We were*1

Chief Staff Manager, Gas Power Fuel Cell Business Department, Mitsubishi Power, Ltd..

*2Chief Staff Researcher, Heat Transfer Research Department, Research & Innovation Center, Mitsubishi Heavy Industries, Ltd.

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also commissioned by the New Energy and Industrial Technology Development Organization(NEDO) to develop gas turbine fuel cell combined cycle power generation (GTFC) and areproceeding with the development to apply the elemental technology in the integrated coalgasification fuel cell combined cycle (IGFC) for the Osaki CoolGen Project. This paper introduces
the development status of MEGAMIE.

|2. Composition of MEGAMIE
Figure 1 illustrates the structure of a cell stack, which is the power generation element of
tubular type SOFC. On the outer surface of the substrate tube, which is a structural member madeof ceramics, cells (laminated anode, electrolyte and cathod) reacting to generate power are formed
and an electron-conductive ceramic interconnector connects these cells in series. Several hundred
cell stacks are bound to form a cartridge and several cartridges are contained in a pressure vessel.
This is called an SOFC module (Figure 2). This system consists of the SOFC, MGT, recycle
blower, etc. Power is generated in the two stages of the SOFC and MGT. Furthermore, when awaste heat recovery device is installed on the exhaust gas line, it can be utilized as a co-generation
system that supplies steam or hot water at the same time (Figure 3(A)).

Figure 1

Structure of cell stack

Figure 2

Composition of hybrid system

Mitsubishi Heavy Industries Technical Review Vol. 58 No. 3 (September 2021)
3Figure 3

Comparison of MGT system and TC system|3. Status of MEGAMIE market introduction and initiatives
We introduced a 250 kW system to the "Next-Generation Fuel Cell Research Center(NEXT-FC)" established in Kyushu University aiming to fully disseminate SOFC by promoting
industry-academia cooperation to use it for the "Verification of a Smart Fuel Cell Society" in theGreen Asia International Strategic Comprehensive Special Zone. After that, in fiscal 2015, underthe NEDO-subsidized project "Technical demonstration of commercial system using solid oxide
fuel cells," demonstration tests under an actual load environment were conducted at four sites:
Motomachi Plant of Toyota Motor Corporation, Komaki Plant of NGK Spark Plug Co., Ltd., Senju
Techno Station of Tokyo Gas Co., Ltd. and Technology Center of Taisei Corporation (Figure 4).
This subsidized project is a task setting type, the respective main subjects/verification items havebeen set at each site as follows and the demonstration tests were carried out: the start/stop operation
test (once a month) for Toyota Motor Corporation, the continuous endurance test for NGK SparkPlug Co., Ltd., the start/stop operation test (once a week for 31 weeks) for Tokyo Gas Co., Ltd. andthe self-sustaining function verification test for Taisei Corporation.

Figure 4Operation and planning status of MEGAMIE

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Based on the results of the demonstration tests, the introduction of the 250 kW class system
to the market commenced in 2017. The first commercial machine was delivered to Marunouchi
building of Mitsubishi Estate Co., Ltd., the second one to Technical Research Institute of Hazama
Ando Corporation and the third one to Ibaraki Plant of Asahi Breweries, LTD. We will also
examine the hydrogen utilization at Hazama Ando and the biogas utilization at Asahi Breweries,
LTD. In addition, the system is scheduled to be delivered to Gas- und Wärme-Institut Essen e.V.
(GWI) in Germany in fiscal 2021 for the first time for overseas installation.
Figure 5 shows an overview of the OCG project. This project calls for the installation of an
integrated coal gasification combined cycle power generation facility (IGCC) in the first step, a
CO2 separation and capture facility in the second stage and SOFC in the third step to verify theIGFC. Toward this third step, for the NEDO Research and Development Project "Research on coalgas application for fuel cell module," which was implemented by Electric Power Development Co.,Ltd. (J-POWER), we delivered a 250 kW class system to J-POWER’s Wakamatsu ResearchInstitute in fiscal 2017 and conducted a verification test using hydrogen-rich gas, which was coalgasified fuel. Since fiscal 2016, we have been verifying a larger module (output 1 MW class andoperating pressure 0.6 MPa class) at Mitsubishi Power Nagasaki Works under the NEDO
commissioned project "Gas turbine fuel cell combined cycle (GTFC) technology development."
We are designing and manufacturing SOFCs for the OCG third stage using these elemental
technology developments as basic design data and planning to start the installation work in fiscal
2021 and verify the coal gasified fuel and high pressure (targeted at 2 MPa) after the trial operationand adjustment.

Figure 5

Overview of Osaki CoolGen Project (first step, second step and third step)|4. Development status of improved MEGAMIE system
Figure 3 compares the SOFC-TC combined system currently under development and theconventional SOFC-MGT combined system. The SOFC-MGT (Figure 3(A)) system is a hybrid
system where the MGT is driven by burning the fuel used and diluted during SOFC power
generation and air in the MGT combustor. On the other hand, the SOFC-TC system (Figure 3(B))
is a cascade system where the fuel diluted at the SOFC module is used to generate electricity at thesubsequent SOFC module stage. The upper-stage SOFC is called the topping module and thesubsequent SOFC stage is known as the bottoming module. The SOFC-TC system uses fuel for
power generation using a highly-efficient fuel cell, so efficiency can be expected to improve. Inaddition, since the amount of air under partial load can be changed, the efficiency under partial load
can also be expected to improve. Furthermore, since the temperature of the turbine inlet combustor
can be lowered, it is expected that its applicability to diversified fuels including hydrogen can beeasily expanded.

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In terms of operation, it is necessary to verify the controllability of the start-up air blower for
starting the TC and the operability at partial load to optimize the controllability in start/stop andrated/partial load operation. For this reason, we installed the SOFC-TC system demonstrator shownin Figure 6 at the Nagasaki Works. Considering transportability, this demonstrator consists of two
topping modules, one bottoming module and an auxiliary equipment unit. The auxiliary equipment
unit consists of a fuel recirculation blower, TC, starter blower, etc. In fiscal 2020, we installed
SOFCs on one topping module and the bottoming module and conducted a verification test on thehalf module system. The improved MEGAMIE uses a cell stack that is being jointly developedwith NGK Spark Plug Co., Ltd. (NTK). We are planning to install a cell stack with even higher
performance on the remaining topping module and conduct verification as a full module system inthe future. We will consider system specifications with an eye on the commercial value of the 1
MW class machine and launch it in the market.

Figure 6External view of 1 MW class half module demonstrator using MGT|5. Conclusion
SOFC is an attractive technology that can be applied to SOEC (Solid Oxide Electrolysis
Cell), which produces hydrogen, CO, etc., by electrolysis when operated in reverse. Therefore,
Mitsubishi Power positions SOFC applications as a trump card that is an effective technology toachieve both the reduction of CO2 emissions and the stable supply of electric power toward therealization of carbon neutrality and decarbonization by 2050, including the transitional period.
Regarding the SOFC-MGT hybrid system, a 250 kW class unit has been on the market since2017 after demonstration projects at Kyushu University and NEDO. Since fiscal 2016, we havealso been developing and verifying MW-class SOFC-MGT units with capacities larger than the 250
kW-class unit and reflecting the elemental technologies cultivated therein in SOFC for OCG, which
verifies the application of coal gasified fuel.
We are also developing a TC system to improve operability. We plan to conduct afull-module system test to verify the operability features such as the start/stop characteristics, ratedoperation, partial load operation characteristics, protection system, etc., in fiscal 2021. We will
steadily establish the technology and enhance its commercial value through this verification and put
the system on the market to make a great contribution to the construction of a "safe and sustainableenergy environment society."(Acknowledgment)This report includes the outcomes from joint research, etc., conducted with the National
Research and Development Corporation New Energy and Industrial Technology DevelopmentOrganization (NEDO) and we would like to express our gratitude to all concerned parties. We are
deeply grateful to the Ministry of Economy, Trade and Industry, the Ministry of the Environment,
the Ministry of Land, Infrastructure, Transport and Tourism, the Tokyo Metropolitan Government
and the relevant ministries and agencies for giving us guidance and advice, as well as to allconcerned parties including the universities, research institutions, electric power companies, gasutility companies and manufacturers for giving us guidance and advice on development andverification.
MEGAMIE is a registered trademark or trademark of Mitsubishi Power, Ltd. in the UnitedStates and other countries.

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6References(1)(2)

Yoshimasa Ando et al., Demonstration of SOFC-Micro Gas Turbine (MGT) Hybrid Systems forCommercialization, Mitsubishi Heavy Industries Technical Review Vol.52 No.4 (2015) p.48～53
Hiroki Irie et al., Efforts toward Introduction of SOFC-MGT Hybrid System to the Market, Mitsubishi
Heavy Industries Technical Review Vol.54 No.3 (2017) p.86～89