Yuichiro Kanematsu

Industrial Symbiosis Centered on a Regional Cogeneration Power Plant Utilizing Available Local Resources: A Case Study of Tanegashima

Plant‐derived renewable resources have the potential to enable the simultaneous generation of high‐value‐added products, such as foods, with energy, such as electricity and thermal power. Much of the heat cogenerated from renewables in power plants has been discarded because of the geographical and temporal gaps in heat supply and demand. In this study, we aim to devise an effective industrial symbiosis (IS) for a regional combined heating and power (CHP) plant utilizing local renewable resources. For the actual region of IS, the island of Tanegashima in Japan was adopted, where sugarcane is planted as a base industry. Through a thermodynamic analysis of the energy flows in a sugar mill, it was demonstrated that large amounts of heat were discarded from the sugar mill, even though the quality of heat was high enough for power generation or other energy demand. This is partly because some of the renewables have been regarded as wastes in the production of foods or other high‐value‐added products. At the same time, scenarios were defined and analyzed on the integrated use of locally available lignocellulosic biomass to increase the operation ratio of an existing bagasse‐based CHP system. Through both periods with and without sugar production, additional heat and power can be made available by decreasing the energy loss and through IS.

Distributed Cogeneration of Power and Heat within an Energy Management Strategy for Mitigating Fossil Fuel Consumption

Distributed energy sources, such as self‐power generation, steam boilers, and combined heat and power production (CHP), are operated to manage the supply of energy by optimizing the costs of meeting the demand for electricity and heat. This article was written in conjunction with reports by the United Nations Environment Programs International Resource Panel that quantifies and compares the environmental and natural resource impacts and benefits of using demand‐side efficient technologies for greenhouse gas mitigation scenarios from now until 2050. In this article, we examine the potential of using distributed energy sources in future energy systems. First, we reviewed the existing research into several energy technologies, especially into cogeneration systems for CHP, using a bibliometric analysis. The current energy supply/demand in the demand‐side sectors in Japan is also reviewed using available statistical data, and an investigation into the energy requirements of industrial manufacturers was performed. After systematizing the results of our review on progress in current research, a scenario analysis was conducted on the potential of distributed energy sources to clarify the contribution of the various technology options. A mismatch between the quality of energy produced, especially heat, or any benefits arising from scale from other energy technologies, can decrease the incentive to implement distributed energy technologies. As a requirement of a regional energy system design and management, distributed energy sources should be considered so that the appropriate technology options can be adopted for the desired energy supply in the demand‐side sector. The possibility exists to replace conventional single‐generation technologies, such as boilers or power generators, with multigeneration technologies. A change in the grid power mix is one of the most sensitive parameters affecting the performance of cogeneration technologies.

Forestry and Wood Industry

Excessively rapid socioeconomic changes in Japan have disrupted national policies related to the management of biomass resources. During the twentieth century, the Japanese forestry and wood industry transformed from producing wood for fuel to wood for construction to support national reconstruction in the postwar era. During this period, conifers were planted on most mountains. However, by the time sufficient conifer forests had grown to supply wood for construction, demand had declined because of the growth in imports. In the meantime, energy security and reduction of carbon emissions have become important issues, leading to the establishment of the “Biomass Nippon Strategy (2002)” and “Feed-in Tariff (FIT) Scheme for Renewable Energy (2012),” which have redirected interest back to the use of woody biomass for energy. However, the age class composition of wood resources in the forests is imbalanced because of the aforementioned transformation. Sustainable forest resource use demands a balanced structure and full use based on efficient collection of wood biomass generated in the supply chain, i.e., from forest to sawmill. It also demands the use of the best available technologies while maintaining other functions such as environmental conservation and watershed protection. In this study, we propose a road map to facilitate development of a sustainable forestry and wood industry that could satisfy demands for energy and construction.

A computer-aided scenario analysis of national and regional energy systems based on feasible technology options

Abstract We developed a method for analysing scenarios of future energy systems implementing a variety of feasible technology options based on an energy flow model. The model was modularized and represented as functionals of appropriate technology options, which enables the aggregation and disaggregation of energy systems by defining functionals for single technologies, packages integrating multi-technologies, and mini-systems. In this study, we applied this model into the future energy-system design in regional and national boundaries of Japan. The combinations of technologies on both energy supply and demand sides can be addressed considering not only the societal scenarios such as resource prices, economic growth and population change but also the technical scenarios including the development and penetration of energy-related technologies such as decentralized solid oxide fuel cells in residential sectors and new-generation vehicles, and the replacement of current technologies such as heat pumps for air conditioning and centralized power generation. Through case studies on national and regional energy systems, it was demonstrated that the contribution of technologies to, e.g., the reduction in greenhouse gas emissions, should be carefully examined by quantitative analyses of interdependencies of the technology options for actual decision-making on energy systems. A micro grid incorporating renewable resources including solar, wind, and biomass can be optimized by implementing industrial symbiosis, which can be strategically designed through energy flows simulation by developed model.

A computer-aided socio-technical analysis on national and regional energy systems considering local availability of renewable resources

Abstract We conducted a computer-aided socio-technical analysis on national and regional energy systems. Existing developed models were simultaneously utilized for characterizing the possible solutions of energy systems with the available technology roadmaps. At the same time, we analysed consumers’ preferences about the electricity supply through preference surveys in whole Japan and a remote island Tanegashima. As socio-technical analysis, the basic information on the performance and behaviour of energy systems and consumers’ preferences were interpreted based on the results of energy-system simulation and willingness to pay calculated by the survey results. The solutions for the design of national and regional energy systems were generated through the consideration of local availability of renewable resources.

A design of rural energy system by industrial symbiosis considering availability of regional resources

Abstract This paper performed the design of rural energy system by industrial symbiosis considering long-term availability of forest resources. As for the case examples, alternatives of energy system in Tanegashima, a remote island in Japan, were examined, where two types of combined heating and power (CHP) were designed. In the first option, bagasse-based CHP at the cane sugar mill was enhanced to use woody biomass as additional fuel and generate energy for district heating and cooling (DHC). In another option, small scale biomass-CHP was designed for DHC in city center. Both options were mathematically modeled and simulated for examining the resource requirements and lifecycle greenhouse gas emission. A constraint on total availability of woody biomass was taken into account, which was calculated through a simulation on forestry. The effect of total timber availability and allocation to the two CHP systems was quantified. A design of rural energy system by industrial symbiosis can be facilitated by simulation-based analysis to visualize the impacts of such energy networks among involved multiple players such as industry, residential, and commercial sectors.