Toshiba Revamps 'Ene Farm' Residential Fuel Cell

Dec 23, 2011
Hideyoshi Kume, Nikkei Electronics
The new product of the "Ene Farm" residential fuel cell. The fuel cell unit measures 780 x 300 x 1,000mm, and its output of power generation is 250 to 700W. The hot-water supply unit manufactured by Chofu Seisakusho Co Ltd measures 750 x 440 x 1,760mm. It can store 200L of hot water at a temperature of about 60 degrees C.
The new product of the "Ene Farm" residential fuel cell. The fuel cell unit measures 780 x 300 x 1,000mm, and its output of power generation is 250 to 700W. The hot-water supply unit manufactured by Chofu Seisakusho Co Ltd measures 750 x 440 x 1,760mm. It can store 200L of hot water at a temperature of about 60 degrees C.
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Toshiba Corp and Toshiba Fuel Cell Power Systems Corp announced that it will release a new product of the "Ene Farm" residential fuel cell for gas companies in March 2012 in Japan.

The power generation efficiency of the new product is 38.5%, which is 3.5% higher than that of the former model released in 2009. And the efficiency of collecting heat generated by power generation was improved from 45 to 55.5%.

As a result, the total efficiency, which is calculated by combining the two kinds of efficiencies, reached 94%, which Toshiba and Toshiba Fuel Cell Power Systems claim is "one of the highest in the world" (based on the low heating value (LHV) standard of city gas). Also, the companies improved the durability of the fuel cell.

For general consumers, Osaka Gas Co Ltd will start selling the new Ene Farm April 2, 2012, for a price of ¥2,604,000 (approx US$33,363), which is about ¥650,000 lower than the price of the former model. Osaka Gas will use Toshiba's fuel cell unit but employ a 200L waste heat-powered hot-water supply/air heating unit manufactured by Chofu Seisakusho Co Ltd.

The Ene Farm has been attracting an increasing amount of attention since the Tohoku Earthquake, which hit Japan March 11, 2011.

"In fiscal 2009 and fiscal 2010, slightly more than 4,000 units of the Ene Farm were sold," said Osamu Maekawa, chief technology executive, Power Systems Company, Toshiba. "But in 2011, we installed about 6,500 units by the end of November. So, we saw a remarkable increase in sales volume, compared with sales volumes in past years."

Toshiba aimed to sell 5,000 units of the Ene Farm in fiscal 2011. And it is now planning to sell 15,000 units in fiscal 2012. In fiscal 2015, the company aims to sell 50,000 units by improving the competitiveness of the product and reducing its costs.

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Durability of 80,000 hours

Costs
For the new fuel cell unit, Toshiba and Toshiba Fuel Cell Power Systems reduced costs by 30%, said Yuji Nagata, chief engineer, Toshiba Fuel Cell Power Systems. For example, they realized an output power equivalent to that of the former product while reducing the number of cells used for the main body of the unit by about 15%. Also, they reduced the amount of platinum (Pt) used as a catalyst material for the unit by about 20%.

Inverter
The two companies separated an inverter and a control board in the former product. This time, however, they were integrated by, for example, redesigning the component layout and employing a multilayer printed circuit board.

In regard to the system package, the number of components was reduced by about 40% by, for example, simplifying the system and employing integrated pipes. As for the reformer, the two companies used the same product as employed for the former model. It is based on hydrodesulfurization, in which Osaka Gas has know-how.

Durability
In regard to durability, the companies realized 80,000 hours of operation, which was increased from 40,000 hours of the product commercialized in 2009. The warranty period of the Ene Farm is 10 years. And the fuel cell of the former product has to be replaced five years after purchase. The new product does not require such replacement.

Moreover, the frequency of required periodical maintenance was reduced from once in two years to once in three and a half years. And, for the new product, maintenance (such as replacing filters and resin films) takes only about 30 minutes. The checkup can be done even when the product is generating electricity.

Fuel
As fuel, the new Ene Farm can use liquefied natural gas (LNG) and liquefied petroleum gas (LPG) as well as natural gas (NG) used in part of Nagano Prefecture and Hokkaido in Japan and 12A gas used in Chiba Prefecture, etc in Japan. It can also use pure hydrogen as fuel in case that hydrogen will become a major fuel in the future.

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Self-sustained operation

Toshiba and Toshiba Fuel Cell Power Systems are considering introducing a self-sustained operation system so that the new product can be used even in the case of power outage. In general, the Ene Farm cannot generate electricity in the case of power outage. But the self-sustained operation system automatically shuts connection to the power grid and supplies electricity to appliances connected to special power outlets.

"If an external battery for emergency is added to an expensive fuel cell system, the price will increase even more," Nagata said. "Considering how frequently power outages occur, we do not want to spend much cost for it. Therefore, we developed a system that can realize a self-sustained operation by using only a fuel cell."

The self-sustained operation system has already been developed and is currently being tested, he said. So, it has not been mounted in the new Ene Farm yet. After finishing the test, the company will equip the Ene Farm with the system as an option, etc. And it is scheduled to be released in fiscal 2012.