Techno-Economic Assessment of Solid Oxide Fuel Cell-Based Biogas Power Plant Projects in Northern Japan

摘要

A techno-economic assessment for biogas power generation projects with solid oxide fuel cells (SOFCs) in northern Japan has identied the required scale, required technological improvements and other key factors for making sucient pro t. Dairy cattle manure was assumed as the organic waste for treatment in biogas plants. It was found that, for a 10,000-cattle scale project, if the only income is from the sale of electricity, the installation and maintenance cost of the biogas plant was the greatest contributor (33%), followed by the labor cost of the truck crew (20%) and the installation and maintenance cost of the SOFC (9.8%) on a present value basis calculated with a discount rate of 2% for a 20 year project period. Focused analyses on SOFC suggested that, under the current domestic situation (ca. FIT 40 JPY/kWh), further research and development to improve the durability of the system to at least ca. 12,000 h is recommended. It was also found that pro tability is aected by the high treatment cost of liquid fertilizer when more is generated than can be sold. R&D to reduce surplus liquid fertilizer by controlling the digestion process is thus important. Besides the abovementioned technology improvements, to reach the break-even to make sucient pro t, it is also necessary to reduce the other dominant costs (biogas plant cost, waste collection cost) and increase the income (sale of by-products). For example, it is eective to shorten the waste collection distance by increasing the farm size, and to increase the income by selling the by-products. With the developed model, it is now possible to synthesize a pro table business plan for a biogas plant with SOFC, that takes these factors into account in advance, and to direct research eorts towards a wider possibility for use in this application.