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Author(s): David G. Victor (corresponding author) [1]; Keigo Akimoto [2]; Yoichi Kaya [3]; Mitsutsune Yamaguchi [6]; Danny Cullenward [4]; Cameron Hepburn [5] Beyond US President Donald Trump's decision in June [...]

A study is conducted to analyze lifetime carbon dioxide emissions from Japanese nuclear power plants. The study also analyzes energy scenarios in Japan.

Current emission scenarios that allow keeping the global temperature increase below 2 °C or even 1.5 °C—as foreseen by the Paris Agreement—are based on very optimistic assumptions, including enormous volumes of carbon dioxide removal (CDR). A closer look at the globally most important emission sectors—power, transport and industry—shows manifold barriers for very ambitious mitigation. A new policy guideline called "Net Zero CO2 Emissions without relying on massive CDR" and promotion of technological research, in addition to economic incentives and other policy measures, would help to overcome the often simplistic demands for positive modelling results and refocus climate policy on tackling the enormous barriers in key emitting sectors. Such an approach is more aligned with the Paris Agreement's bottom-up logic and therefore more appropriate to make the transformational project of global decarbonization a success. [ABSTRACT FROM AUTHOR]

In Japan, electric power utilities purchase electricity from independent power producers (IPPs) through competitive bidding; the IPP evaluation is based on the avoided costs of corresponding generators of utilities. In this evaluation, however, nonpricing factors such as power flow constraints in the electric power system cannot be considered. In this paper, we propose a new approach to evaluate economic impacts of IPPs, the IPP electricity being priced on the basis of total generating costs of the electric power utilities. Such a price to purchase the electricity of IPPs is referred to as the “break-even cost.” The main results are summarized as follows: 1) Break-even cost depends on not only the power flow constraints in the system, but also various IPP factors such as generating pattern, location, and capacity, 2) Break-even cost for the base-type IPP is higher than the avoided cost of corresponding utility generators, because IPPs located on demand sides can reduce the transmission power loss in the electric power system, 3) Break-even cost is affected by available capacity of utility generators, especially for the peak-type IPP generating only during peak demand periods. © 2000 Scripta Technica, Electr Eng Jpn, 133(2): 20–30, 2000 [ABSTRACT FROM AUTHOR]

District Heating and Cooling (DHC) combined with a Cogeneration System (CGS) is one of the most efficient ways to supply energy to the commercial and residential sectors. This paper discusses the feasibility of introducting DHC from the viewpoint of the overall energy saving effect in Japan's energy system as a whole. Although DHC is efficient for congested areas such as urban business centers, these areas are limited in capacity and number. In our evaluation of the feasibility of introducing DHC, we consider the energy demand density profiles of Japan's commercial and residential sectors in order to determine the installed DHC capacity that is optimal for meeting the growth of energy demand. This paper also discusses operating patterns of CGS and of boilers in DHC. In order to improve the efficiency of individual DHC facilities, CGS should be operated so as to satisfy heating demand, resulting in a low annual load factor. On the other hand, the overall efficiency of the energy system requires an improvement of the overall load factor of CGS, which is achievable by combined use of CGS and boilers. Operation of CGS in this manner improves the feasibility of the introduction of DHC. © 2000 Scripta Technica, Electr Eng Jpn, 133(2): 31–42, 2000 [ABSTRACT FROM AUTHOR]

Global warming is one of the most serious issues in today's world. Various innovative technologies have been proposed for the reduction of CO2 emissions and the mitigation of global warming. They include (1) the WENET project, inaugurated in 1993 by the government of Japan, in which electricity produced by photovoltaic systems in vast areas such as the Sahara Desert, or by hydropower systems, is converted to hydrogen for transport to demand sites, and (2) Steinberg's Hydrocarb process, in which fossil fuels and biomass are coprocessed to produce carbon and methanol. While Japan is resource-poor, it is located relatively close to Southeast Asia and Australia, which are large regions with abundant solar energy. This paper describes an investigation of the prospects for the adoption of these innovative technologies by Japan and surrounding resource regions in the next 30 to 40 years. An optimizing energy model is developed for the purpose, and the simulation results provide several interesting suggestions regarding Japan's future strategy for combating global warming. [ABSTRACT FROM AUTHOR]

This paper presents a new method for power system planning which considers uncertainties of various system parameters as a part of the criterion function. The criterion function involves both the expected values of total system costs and the cost variances of different power plants. Previously, the authors proposed that these cost variances be evaluated from the existing power system plans in the form of the solutions to the inverse optimization problem, and then applied this procedure to the planning of power systems in Japan. However, because of the correlation between fuel and facility costs, the cost variances could not be determined as specific values. Here, to overcome this difficulty, the authors now introduce hydropower plants into the model as the so-called nonrisky elements and focus on the expenditure shares rather than the plant capacity shares. As a result, more reasonable results are obtained. This improved methodology is applied and the derived cost variances are shown. Further, using the resultant cost variances, the authors make Pareto-optimal power generation plans and demonstrate also the robustness of the method to price fluctuations. [ABSTRACT FROM AUTHOR]

Something should be done for a better global environment as soon as possible. This paper investigates the direction of management of the global environment and proposes new, concrete ideas for it. [ABSTRACT FROM PUBLISHER]

The future demand for electricity is uncertain and difficult to forecast, but it is necessary to do so in order to construct power plants. In that sense, a large-scale power plant is disadvantageous because it takes a long time to construct. On the other hand, although it takes less time to construct, a small-scale power plant is more expensive. Therefore large- and small-scale power plants could complement the disadvantages of each other. This paper develops a stochastic dynamic programming model to investigate the possibility. The model determines the capacities of large- and small-scale power plants in the face of uncertain demand to minimize the expected value of the total cost. Computed results have shown that small-scale plants can play a significant role in this case even if they are more expensive than large-scale plants. [ABSTRACT FROM AUTHOR]

Future energy supplies are uncertain, especially in view of environmental problems, fuel prices, and energy demand. In this paper two types of novel energy plants and a novel energy system have been proposed to cope with these conditions. The first type can utilize multiple kinds of fossil fuels and economically remove CO2 and the second can produce multiple kinds of final energy to cope with fluctuations in the energy demand. Characteristics of a novel energy system (a Flexibly Integrated Energy System; FIES), which includes novel energy plants as described in the foregoing, have been investigated with a linear programming model. A reference system has also been represented which behaves similarly to the present energy system for comparison. Computed results have demonstrated that CO2 emissions can be reduced more economically and efficiently than in the reference system if it is combined with CO2 removal systems. [ABSTRACT FROM AUTHOR]

R&D (research and development) processes of CO2 capture technologies having different levels of energy efficiency are evaluated through GERT (Graphical Evaluation and Review Technique) analyses. Five types of the technologies are targeted for evaluation: chemical absorption, physical adsorption, membrane separation, O2/CO2 recirculation boiler, and integrated hydrogen separation gas turbine technologies. These technologies are decomposed into elemental technologies, and network charts are constructed which express R&D processes of the target technologies for the GERT analyses. Data on the elemental technology R&Ds are collected through a questionnaire to Japanese experts in 2001, and are used for the evaluation. The obtained results include that (1) the average expected time periods required for the completion of the target technology R&Ds are in the range of 16 and 19 years, except for a shorter R&D time of 13.8 years for the chemical absorption CO2 capture technology having the conventional energy efficiency, (2) though the R&D success probabilities are relatively high for the chemical absorption type CO2 capture technologies, they become lower as the energy efficiency becomes higher, which implies that the R&Ds of the capture technologies other than the chemical absorption type are also recommended for the successful completion of the capture technology which has the highest energy efficiency among the target technologies, and (3) additional R&D investments on large scale equipment such as tower, blower and pumping technologies are cost-effective for accelerating the target technology R&Ds. [Copyright &y& Elsevier]