Toyota Motor Corporation (TMC) and Aisin Seiki Co., Ltd. (Aisin) plan to provide 60 2010-model residential, solid-oxide fuel-cell (SOFC) cogeneration systems jointly developed by Osaka Gas Co., Ltd. (Osaka Gas), Kyocera Corporation (Kyocera), TMC and Aisin to the New Energy and Industrial Technology Development Organization’s (NEDO) Solid Oxide Fuel Cell Verification Project. Five companies are participating in the project: Hokkaido Gas Co. Ltd., Tokyo Gas Co., Ltd., Toho Gas, Ltd., Osaka Gas Co., Ltd. and Saibu Gas Co., Ltd.
TMC and Aisin provided equipment for the project’s 2009 test program. (Earlier post.) The 2010 models have overcome the technological development issues identified through earlier test programs to achieve greater energy savings and CO2 reductions. They feature higher load efficiency of the power-generating unit during low output (partial load efficiency) and greater hot water tank capacity, resulting in more effective use of waste heat. In addition, durability and ease-of-maintenance have also been improved to enhance product marketability.
By providing the new models to the project, TMC and Aisin hope to accelerate development of residential SOFC cogeneration systems, completing development within the first half of the 2010s.
Higher partial load efficiency was achieved through improved heat insulation of the module (made up of cell stacks and fuel reformers) as well as greater use of waste heat by increasing the capacity of the hot water tank.
Insulation material surrounding the module has been increased to reduce radiant heat loss, and the temperature distribution within the module has been optimized. Thus, partial load efficiency has been improved and generating efficiency when generating volume is below the set rating is higher than the 2009 model.
The depth of the hot water tank has been increased by 10 mm, raising the tank capacity from 70 liters to 90 liters and achieving more effective use of waste heat. As a result, high generating efficiency can be maintained regardless of the electrical power demand, cutting both running costs and CO2 emissions.
The coating material on the metal current collector material placed between the cells in the cell stack has been modified and the temperature distribution within the module has been optimized, improving durability.
The amount of the desulfurizing agent added to the natural gas as an odorant has been increased, making the desulfurization unit maintenance-free for 10 years. In addition, temperature management of the desulfurizing agent prevents deterioration from water vapor in the gas.
Energy savings have been increased by switching to a latent-heat-recovery boiler from a boiler that did not recover heat from the condensed water in the exhaust gas (latent heat).
The new units carry a rated power generation output of 700W, with rated generation efficiency (LHV) of at least 45%.