Comment: “Osaka Gas, with our experience of marketing the largest number of homeuse cogeneration systems in the world, has been engaged in designing and evaluating SOFC from the standpoint of CHP utilization. We currently offer SOFC on natural gas but may introduce units for use on LPG. Once further cost reduction and higher efficiency is achieved, broadening the scope of market introduction of SOFC through commercial and industrial uses may also be examined. We have made some great achievements with SOFC relating to the world’s highest power conversion ratio at 46.5%, but of course there have been challenges of the core device materials with a 50% platinum reduction in the catalyst from the previous model. There was also an MEA cost reduction by developing base material-less GDL, achieving the balance between the strength and conductivity by optimizing the compounding ratios of carbon fibre and PTFE. This model has also interestingly increased the number of applicable gas types, with an improved tolerance to gases containing nitrogen. The Panasonic ENE-FARM is being adopted by most of the major regional gas companies in Japan, including Hokkaido Gas, Tokyo Gas, Hiroshima Gas, Saibu Gas, Toho Gas and Shizuoka Gas. It is clear that this PEFC model is leading the market at present, with a major advantage being its suitability for the heavy start/stop cycling required in a domestic set-up.
“The Panasonic ENEFARM model is being adopted by most of the major regional gas companies in Japan” The SOFC still poses challenges for the domestic market with slow start-up operation because of the ceramic cells’ weakness to rapid temperature change, but it’s flexibility on input fuel and subsequent ability to be connected directly to natural gas networks makes it an irresistible choice, not forgetting that it offers the highest electrical efficiency of all fuel cell products, and distinct space saving features through a smaller water storage tank requirement. The differing characteristics of these ‘competing technologies’ is driving end-user purchase decisions to be motivated by desire for enhanced operational efficiency or extended cycling duties. It is certainly not an easy decision in the modern climate.
64 POWER INSIDER MAY / JUN 2013
So When Did SOFC Figure in ENE-FARM? After an astonishing amount of research, development and persistence, an SOFC model was finally added to the ENE-FARM scheme in 2011, under the ENEOS brand through Japan’s largest oil refiner, JX Nippon Oil and Energy Corporation. The product is currently available for $31,000 USD and comes with a ten year warranty, which may seem expensive in comparison to PEFC, but JX forecast bringing the unit cost crashing down to a figure close to $5,000 USD by 2015. The major future difference in price to the PEFC version is primarily down to the absence of precious metals like platinum, but also the component and raw materials price shifts when large scale commercialization is underway. If the ENEOS SOFC range does come down in cost by the sums anticipated, it will put an entirely new spin on the aforementioned argument. Taking advantage of the accumulated technologies and know-how of petroleum refining, JX Nippon Oil & Energy Corporation were always going to offer a very unique insight into the use of petroleum-based fuels such as LPG, naphtha and kerosene in a Solid Oxide Fuel Cell. That expertise has clearly paid off through their head start on introducing the SOFC into the ENE-FARM programme. The Osaka Gas Alliance Osaka Gas and Kyocera launched a joint program to develop a cell stack in 2004 which was later joined by Toyota and Aisin in 2009. During this period, Osaka Gas and Chofu also started R&D work on a waste heat recovery/ utilization unit for water heating, with a clear expectation of fast adoption for the promising domestic market in Japan. The end result was the ENE FARM Type ‘S’ solid oxide fuel cell, which is currently available for $28,000 USD. The research and development phase has been a long process for Osaka Gas, so when the product officially became commercial on April 27th 2012, it was a great milestone for all of the different components concerned. The road to retail has led
on the way. Prior to commercialization, we conducted tests and analysis of cell deterioration mechanisms and worked on identifying those elements in order to evaluate their performance in a ten-year operating period. We are continuing the work on acceleration tests for each deterioration element to ensure long-term durability of cell stacks. We are of the view that SOFC in particular, has the potential to become a major energy supply system for households, because of the high energy efficiency features of power generation & heat utilization. It is on this basis that further cost reduction will undoubtedly be achieved.” Osaka Gas to be heavily involved in the evaluation of environmental acceptance, reliability and durability of SOFC, through the testing of 121 units during the “Demonstrative Research on Solid Oxide Fuel Cell” project undertaken by the New Energy and Industrial Technology Development Organization (NEDO) and the New Energy Foundation. This verification initiative was combined with the evaluation and study on the long-term durability of coating materials on power collecting metals for connecting cells. The SOFC system has been developed based upon the companies’ competence in areas such as the design, installation and maintenance from Osaka Gas for co-generation systems; the design and production technology of Kyocera for cell stacks; the design and production technology of Aisin/Toyota for generation units; and Chofu’s design and production technology of hot-water supply and heating units using exhausted heat. The system is environmentally and economically enhanced, eliminating annual CO2 emissions by about 1.9 tons, while also reducing annual energy costs by over 30% in comparison to ordinary gaspowered hot water supply and heating units. The back-up boiler ensures that there is an uninterrupted hot water supply, whilst the efficient power conversion offers continuous electricity supply for 80% of household power needs. Moreover, due to the low number of parts and small quantity of exhaust energy, a compact design was made possible for both the power generation