Development History of Latest Ene-Farm Type S (2020 Model)

Purpose of Development

People have been increasingly caring about energy, driven by the recent social trends such as the liberalization of the energy market, users’ growing interest in energy saving and creation, and the spread of zero-energy houses (ZEHs).

Osaka Gas has been working on the development and dissemination of Ene-Farm, a fuel cell cogeneration system for residential use, to build a low-carbon society by facilitating energy saving and CO₂ emissions reduction in the residential sector. The Ministry of Economy, Trade and Industry’s Strategic Energy Plan (decided by the Cabinet in October 2021) aims to introduce 3.0 million Ene-Farm units by 2030. To help reduce society’s overall environmental impact, it is necessary to further popularize Ene-Farm.

・ To provide customers with equipment that has improved energy-saving performance and environmental friendliness

・ To enable equipment to be used by more customers by making it more affordable and compact

To achieve these goals, we are working on developing a new model of Ene-Farm type S so that it will be beneficial for both customers and society as a whole.

Overview of the Latest Model (FY2020 Model)

In 2012, the first model of Ene-Farm type S was released. Through further development efforts, a new product was released in April 2020.

＜Main features of the new product＞
(1) Improved power generation efficiency
Owing to the improved cell stack and the better control program of the power generation units, the new product achieves the world’s highest power generation efficiency (55%) as a household fuel cell system whose rated output is 1 kW or less. Accordingly, the current model’s power generation efficiency of 53.5%, the world’s highest, has been exceeded. (Osaka Gas survey as of the end of January 2020)

(2) Ease of installation has been improved by significantly downsizing the power generation unit.
The width has been reduced from 780 mm (current model) to 600 mm by reducing the number of cells in the cell stack and downsizing the power conditioners. As a result, the installation footprint has been reduced by about 20%. [Installation footprint: 1.1 m² (new product) ← 1.4 m² (previous model)

(3) Improved durability
By reviewing the durability of the cell stack, which is the main device, the service life of the power generation unit has been extended from 10 years (previous model) to 12 years so that the product can be used for a longer period.

(4) Improved convenience owing to enhanced IoT services
The convenient Tsunagaru Switch has been added to the remote controller. The switch is equipped with convenient functions that work with a special smartphone app.

* Click here for 2020 models.

Exterior of new product [power generation unit (left) and heat source unit (right)]

* Power generation efficiency when rated power generation is continued stably for at least three hours (e.g. under the surplus
electricity purchase system). In the cases other than the above, the rated power generation efficiency is 54% (overall efficiency: 87%).

High Power Generation Efficiency for Higher Environmental Friendliness

The power generation efficiency of Osaka Gas’s Ene-Farm and Ene-Farm type S models has improved with each generation. The new product offers significantly improved performance made possible by reviewing some aspects of the manufacturing method for modifying the interface between stacked cells in the cell stack manufactured by Kyocera Corporation.
In addition, the power generation unit manufactured by Aisin Seiki Co., Ltd. was reviewed as to the method of controlling fuel and water supplied to the cell stack during stable operation at the rating in order to ensure operation at higher power generation efficiency. Furthermore, the power conditioner was also modified for higher AC/DC conversion efficiency. These improvements have allowed the new product to surpass the power generation efficiency of the 2018 model, achieving the highest power generation efficiency of 55% in the world’s highest class.

Ease of Installation for More Customers to Use

The improved cell stack offers improved power generation efficiency and at the same time has a reduced number of cells. Indeed, the number of cells, which was 140 in the first model launched in 2012, has decreased to 78. The total length of the piping has also decreased owing to downsized auxiliary equipment, including the power conditioner and hot water storage tank, and optimization of the internal layout of the power generation unit. Consequently, the power generation unit has a slim width of 600 mm in comparison with 780 mm of the 2018 model, or an approximately 20% reduction in installation footprint.
The mass of the power generation unit has also been reduced from 106 kg to 86 kg. Downsizing as described above has made Ene-Farm suitable for installation in a space of approximately 1.1 m2 in a detached house. It is also possible to install it in the shared corridors and balconies of newly built housing complexes.

Resilience Ensured by Self-sustaining Operation to Make Electricity and Hot Water Available in the Event of Grid Failure

If a grid failure occurs, the model with a self-sustaining function during power generation operation automatically switches to self-sustaining operation after about 90 s and starts supplying power to the dedicated outlets. The dedicated outlets are able to supply power up to 700 W.
Meanwhile, Ene-Farm automatically shuts down at regular intervals to evade the functioning of the leakage detection feature of the gas meter. If a grid failure occurs during this shutdown, Ene-Farm will be unable to evoke its self-sustaining power generation function. To avoid such cases, in July 2019, Osaka Gas began a new support service to ensure continued power generation by remote-controlling Ene-Farm to shut down ahead of schedule if a grid outage is anticipated due to a typhoon or the like.
Moreover, the electric water-heating mode has been newly developed to utilize the anti-freezing heater in the power generation unit for water heating. This mode allows customers to use hot water even when the supply of city gas is interrupted.

* Example figures of rated power consumption are shown. Actual power consumption will vary depending on product type and usage.
　Please connect appliances one by one while checking the power consumption with the remote controller.
* Because the power consumption by the backup heat source unit should be included, the available electricity with the dedicated outlets in self-sustaining mode may be less than 700 W. (This applies to installation of the combination of a fuel cell power generation unit and a backup heat source unit.)
* Water heating is not available when the water supply is cut off.
* Some refrigerator models may not be used.

Use of IoT for a More Comfortable Life

The convenient Tsunagaru Switch has been added to the kitchen and bathroom remote controllers. You can assign one of the following four functions to the Tsunagaru Switch on the remote controller. The new product works with a special smartphone app. When the remote controller switch is pressed, push notifications are delivered to the user’s smartphone. Messages sent from the smartphone are displayed on the remote controller at home. These convenient functions designed to facilitate communication in the family are just a few examples.
Additionally, if the remote controller is connected to the Internet line, Osaka Gas is able to provide a service to remotely monitor whether the equipment is operating normally. Furthermore, using this function, Osaka Gas can remotely update the software required for operation control when its improved version is released so that customers can use the equipment with an increased sense of security.

Ene-Farm as a Distributed Power Source for VPP

Ene-Farm is a system that can provide a stable power supply regardless of the weather and may contribute to grid stabilization by complementing solar power generation, whose output fluctuates depending on the weather. For example, when the weather is sunny and there is an oversupply of photovoltaic power generation, the output of Ene-Farm can be reduced to increase its electricity demand or be raised in rainy weather or sudden bad weather.
By taking advantage of the ability to flexibly control the output power and persistent Internet connection of Ene-Farm, multiple Ene-Farm units can be controlled as energy resources, as if they are a virtual power plant (VPP), so as to utilize them for effective adjustment of grid supply and demand. Osaka Gas will participate in the VPP aggregator business subject to the “FY2020 Subsidy for the Demonstration Project for Building Virtual Power Plant Using Customer-side Energy Resources” provided by the Ministry of Economy, Trade and Industry. Under this business, the company will begin a demonstration of adjustment of grid supply and demand using approximately 1,500 units of Ene-Farm type S installed at customers’ homes (the sum of power output ratings reaching around 1 megawatt).

For further information:

About Solid Oxide Fuel Cells

SOFC System Development History