デンマークにおける畜産糞尿リサイクルによる発電および地域暖房計画の環境経済的考察 : 中央集中管理型バイオガス工場を事例として

Abstract

In Denmark, Centralized Biogas plant projects have been established since 1980s. As well known, pork industry and dairy industry have been major agricultural industries in Denmark and the disposition of animal industries manure and waste has been serious environmental issues in this country so far. Also, district heating system has been common and popular nationwide. And so, there were big demand for clean energy to generate heat and power for this purpose. In order to solve this situation, the project was created to establish the centralized biogas plant which could generate heat and power by using animal manure and waste. The purpose of this paper is to describe the economic efficiency and the environmental effects of the centralized biogas plant projects in Denmark. The activities of the biogas plants have created the environmental benefits, such as the reduction of greenhouse gasses emission, mitigation of odor nuisances and the saving of natural resources through recycling. However, in economic terms, some plants have suffered from low profitability. In order to develop the centralized biogas plant projects in the future, it is necessary to decrease the dependency on the government subsidy and the industry wastes as the additional input because their supply is neither stable nor reliable. In addition to these, technical improvements are required to increase efficiency of plant operation through reduction of production costs.