Linear-programming bottom-up energy systems models are useful tools for economic and environmental technology assessment. The conventional approach is to consider several cases with different assumptions and compare their results. The conventional approach is surely based on sensitivity analysis; however, range analysis has the potential to derive information from the models more systematically. This study investigates the applicability of range analysis to the linear-programming bottom-up energy systems model. A simple hypothetical energy system model is considered as a case study. Comparing the conventional approach with the range analysis approach, this study demonstrates that range analysis provides useful information such as the accurate marginal abatement cost curve and cost targets for introducing new technologies, unlike the conventional approach. This paper also shows the range analysis is applicable to a degenerate model.

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In order to realize CO₂ reduction in the future, we have to consider not only induvial measures but also integrated energy-chains, which includes processes from energy production, to transportation, energy conversion, end-use technologies, and energy services. The future energy chains with VREs in a large scale must harmonize time-patterns of supply and demand of electricity considering measures of both supply and demand sides. The purpose of this study is to evaluate an effect of active operation time-patterns of electric appliances such as heat-pump water heaters (HPWHs) and electric vehicles (EVs) considering energy-chains in Japan. For that purpose, the author developed an energy model considering energy chains that includes 21 kinds of energy services with power generation systems in detail. Using the model, the author conducted simulations and obtained the following results. If active operation-time patterns concerning HPWHs and EVs are assumed in 2050, it increases the costs of end-use technologies but decrease fossil fuel costs and CO₂ emissions in Japan. The energy-chains in 2050 shows the shifts of energy chains such as thick chains of electricity and slim chains of fossils, compared with those in 2010.

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Cogeneration system (CGS) is expected to provide flexibility of energy system on the basis of its swift responsiveness of power output adjustment under large-scale integration of renewable energy, as well as to make multiple contributions in primary energy conservation, CO₂ mitigation and BCP (business continuity plan) enforcement. CGS serves as measure for electricity load shedding if CGS output increases by using the idled capacity, while CGS plays a role in electricity load extension if CGS output goes down and electricity is alternatively purchased from power grid. This paper investigates the potential of demand response (DR) by the utilization of CGS, composed of gas-engine and gas-turbine systems, nationwide in Japan and attempts to evaluate the implementable possibility of the CGS-based DR by an optimal power generation mix model, highlighted by detailed geographical resolution derived from 352 nodes and 441 bulk power transmission lines with hourly temporal resolution through a year. The results suggest that the cost reduction of CGS promotes the introduction of electric power load-shedding and the massive integration of renewable increases the implementation of load extension by CGS-based DR.

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In response to the introduction of fuel cell vehicles (FCVs) to the commercial market hydrogen station deployment needs to be progressed. Since resources allocated for deployment are limited for either private companies who wish to install stations and governments who provide subsidies, efficient station allocation should be cognizant of the service of potential customers. Based on a literature review, the results of a social survey and data analysis, p-median is chosen to find optimum locations for hydrogen stations. Location and the amount on potential demand for FCV’s in the early stage of deployment is estimated by a regression model. The result of GIS analysis for short mid-term perspective using p-median implies the importance of covering regional hub cities (such as prefectural capital cities) as well as metropolises and the result of GIS analysis for long-term perspective implies the ultimate necessary deployment of hydrogen stations. The locations suggested by the analysis were examined through coverage analysis on existing gasoline stations. The geographical tendency of station locations allocated by the developed methodology provides guidance for hydrogen station location practice.

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