Panasonic Corporation has started an experiment to utilise heat produced during power generation using pure hydrogen fuel cell generators as a heat source for an absorption chiller.
The experiment will be performed in the H2 KIBOU FIELD facility (Kusatsu City, Shiga Pre
fecture), which uses renewable energy to supply the electric power required for production in the fuel cell factory.
Up to this point, there has been a gap of 20°C between the heat that can be recovered from pure hydrogen fuel cell generators (maximum of 60°C) and the heat source temperature required for the operation of absorption chillers (minimum of 80°C).
This made it difficult to utilise heat produced by pure hydrogen fuel cell generators during power generation as a heat source for absorption chillers.
This time, improvements have been made to both of the hydrogen fuel cell generator and absorption chiller.
The new fuel cell generator produces heat at a temperature of 70°C, which can be used as a heat source for the new absorption chiller for operation, improving the temperature gap by 10°C each.
This has enabled a new solution for the linked use of heat at 70°C by connecting the new fuel cell generator and air conditioning equipment.
In the H2 KIBOU FIELD facility, ten pure hydrogen fuel cell generators with improved hot water output temperature will be installed, along with one newly developed absorption chiller that can utilize low-temperature waste heat.
Such equipment will be used for cooling and heating the facility's administration building as the demonstration experiment of a new scheme to utilize heat.
Throughout the demonstration experiment, Panasonic aims to improve energy efficiency through fuel cell cogeneration (combined heat and electric power supply) and reduce power consumption in cooling and heating equipment, thereby verifying the marketability and effectiveness of this integrated heat utilization solution.
The H2 KIBOU FIELD facility at Panasonic's Kusatsu Site uses 99 units of 5 kW-type pure hydrogen fuel cell generators, photovoltaic generators with an output of approximately 570 kW, and storage batteries with a storage capacity of approximately 1.1 MWh.
These three types of systems are highly integrated and controlled to generate electric power for the fuel cell factory through in-house power generation using renewable energy. Since the Fiscal Year ending in March 2023, the company has been conducting another type of demonstration experiment to efficiently and stably supply renewable energy to the factory by reducing surplus power generation and wasteful power use, through energy management that tracks and addresses demand changes in the fuel cell production process and sudden fluctuations in photovoltaic generator output due to weather.
In this new demonstration experiment for verifying heat utilization, a new catalyst currently under development has been incorporated into the power generation section of the new pure hydrogen fuel cell generator.
Further, improvements have been made to increase the durability of the main body, thereby raising the temperature of the recoverable heat by 10°C, from 60°C to 70°C. Through this demonstration experiment, Panasonic will achieve an energy efficiency of 95% by simultaneously utilizing heat in addition to electric power.
In addition, while heat utilization has previously focused on hot water supply and heating, it will now be possible to use heat for air cooling through absorption chillers. This will enhance the practicality of cogeneration systems in industrial applications and explore new possibilities for heat utilization.
Meanwhile, Panasonic's absorption chillers, which boast a top market share in Japan, are highly efficient air conditioning systems. By using water, a natural refrigerant, the chillers do not use any specified CFCs or alternative CFCs, making them environmentally friendly systems that reduce the impact on the depletion of the ozone layer and global warming. Their lineup also includes a waste heat recovery type that utilizes heat emitted from factories and other facilities to operate equipment.
This experiment is equipped with a new absorption chiller in which the process of absorbing water vapor and concentrating the absorbing solution has been improved.
While the chiller is the same size as existing products, it has lowered the minimum heat source temperature requirement by 10°C, from 80°C to 70°C, making it possible to utilise the heat produced by pure hydrogen fuel cell generators during power generation.
Further, chilled water generated by the absorption chiller will be used for the commercial air conditioners that cool and heat the administration building in the demonstration facility. This experiment is the industry's first attempt to use chilled water from the absorption chiller to achieve the energy saving of commercial air conditioners, aiming to reduce the air conditioning power consumption by 50 per cent.
In addition, lowering the minimum heat source temperature required by absorption chillers has the potential to address the current issue where heat below 80°C, which accounts for approximately 70 per cent of all industrial waste heat emitted from factories and other facilities, cannot be effectively utilised.