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The growing demand for electricity, driven by factors such as the shift to carbon neutrality and economic growth, is a challenge shared by South Korea and Japan. South Korea, a peninsula nation, and Japan, an island country, which are both heavily dependent on foreign energy sources and have manufacturing-based industrial structures, are actively working to secure stable power supplies for their economic development. This article carries out a quantitative analysis of the roles of the South Korean and Japanese electric power sectors (EPSs) in their respective economies, seeking to identify differences and generate actionable insights for decision making and policy formulation. Utilizing the input–output (IO) technique with the latest available data, the analysis includes a demand-side model, a supply-side model, and a price-side model to examine various effects of the EPSs. The key findings reveal differences in the production-inducing, value-added creation, and job-creation effects between the two countries, highlighting operational disparities in their electricity sectors. Additionally, South Korea exhibits higher wage-inducing, supply shortage, and price-side effects than Japan, because of its public enterprise-oriented high-wage structure and a substantial manufacturing sector. These quantitative results provide valuable reference material for future government decisions and policy development in the EPS and emphasize the significant role and impact of the power sector in both countries. [ABSTRACT FROM AUTHOR]

In pursuing Japan's target of net zero greenhouse gas (GHG) emissions by 2050, decarbonization strategies at the regional level have been taking place nationally. Some successes have been achieved in the residential sector in achieving decarbonization at the regional level due to improvements in the advancement of energy-saving technologies. An important prerequisite to achieving further decarbonization in the residential sector is understanding household electricity consumption of power demand objects. This study constructed a method for predicting residential electricity consumption in a case study region. First, we set up six models of household composition for scenario exercises. Then, we used the residential energy estimation based on daily activities (REEDA) method to calculate the hourly electricity consumption of each household composition in the four seasons based on the duration of daily life activity. Finally, we separately explore the impact of housing performance (insulation, airtightness), air-conditioning patterns (intermittent operation method in a habitable room/continuous operation method in a habitable room/continuous operation method in all rooms), and geographical location on residential air conditional electricity consumption. The output is a regional residential energy estimate method that can consider multiple key variables. We verified the developed model by (1) comparing the estimated output with the Japan Energy Database and (2) testing the method for various residential areas in Japan. The results showed an accuracy level greater than 75% and nationwide applicability. [ABSTRACT FROM AUTHOR]

In Japan, mechanical plastic recycling has been widely practiced. In recent years, the chemical recycling method has been gaining interest, especially due to its high-quality products similar to virgin materials. Understanding the environmental impact of both methods from the energy consumption standpoint is crucial so that attempts to preserve plastic resources can be based in the most energy-sustainable way. This research aims to determine the environmental impact of mechanical recycling and two types of chemical recycling technologies (coke oven and gasification) by analyzing their energy usage and environmental loads. The results relating to the electricity consumption and water usage show that mechanical recycling results in a 17% share of global warming potential (GWP), coke oven 51%, and gasification 32%. Although mechanical recycling results in a lower GWP, chemical recycling yields highly valuable products and byproducts that can be reused in its processes, such as steam and industrial water, reducing the overall environmental load. These recovered materials are also potentially useful for other industrial processes in an industrial symbiosis ecosystem. [ABSTRACT FROM AUTHOR]

Process heating is typically more than half of the total final energy demand in the textile industry, most of which is usually provided by fossil fuels. There is significant potential to decarbonize the textile industry by the electrification of process heating where low-carbon electricity is used. This study aims to quantify the potential for the electrification of process heating in the textile sector in three of the top textile manufacturing and exporting countries in the world. The results show that the total annual potential energy savings due to the electric steam boiler applications are estimated to be around 92, 2.4, and 2.5 PJ in China, Japan, and Taiwan, respectively, by 2050. This is equal to approximately 19% of the total boiler energy demand in the three economies. Similarly, annual potential energy savings of 8.6, 0.21, and 0.24 PJ can be realized if the existing fossil-fuel-fired thermal oil boilers are electrified in the textile industry in China, Japan, and Taiwan, respectively, by 2050. Moreover, the potential CO2 abatement resulting from the electrification is highly dependent on the carbon intensity of the electricity used. The economic analysis shows that switching from combustion boilers to electric boilers may result in higher energy costs primarily because the average electricity prices in all three economies are substantially higher than fossil fuel prices. Finally, some key recommendations that different stakeholders can take to scale up electrification in the textile industry are provided. [ABSTRACT FROM AUTHOR]

CO2 emissions associated with hydrogen production can be reduced replacing steam methane reforming with electrolysis using renewable electricity with a trade-off of increasing energy consumption, water consumption and cost. In this research, a linear programming optimization model of a hydrogen production system that considers simultaneously energy consumption, water consumption, CO2 emissions and cost on a cradle-to-gate basis was developed. The model was used to evaluate the impact of CO2 intensity on the optimum design of a hydrogen production system for Japan considering different stakeholders' priorities. Hydrogen is produced using steam methane reforming and electrolysis. Electricity sources include grid, wind, solar photovoltaic, geothermal and hydro. Independent of the stakeholders' priorities, steam methane reforming dominates hydrogen production for cradle-to-gate CO2 intensities larger than 9 kg CO2/kg H2, while electrolysis using renewable electricity dominates for lower cradle-to-gate CO2 intensities. Reducing the cradle-to-gate CO2 intensity increases energy consumption, water consumption and specific cost of hydrogen production. For a cradle-to-gate CO2 intensity of 0 kg CO2/kg H2, the specific cost of hydrogen production varies between 8.81 and 13.6 USD/kg H2; higher than the specific cost of hydrogen production targeted by the Japanese government in 2030 of 30 JPY/Nm3, 3.19 USD/kg H2. [ABSTRACT FROM AUTHOR]

As for research on sector-coupled energy systems, few studies comprehensively deal with energy carriers and energy demand sectors. Moreover, few studies have analyzed energy conversion functions such as Power-to-Gas, Power-to-Heat, and Vehicle-to-Grid on the energy system performance. This study clarifies the required renewable resources and costs in the sector-coupled energy system and cost-optimal installed capacity and operation. We formulated an optimization model considering sector coupling and conducted a case study applying the model in the Tohoku region. As a result, due to sector coupling, the total primary energy supply (TPES) is expected to decrease, and system costs are expected to increase from 1.8 to 2.4 times the current level. System costs were minimized when maximizing the use of V2G by electric vehicles and district heating systems (DHS). From the hourly analysis, it becomes clear that the peak cut effect by Power-to-Heat and the peak shift effect by Vehicle-to-Grid result in leveling the output of electrolyzer and fuel synthesizer, which improves the capacity factor reducing capacity addition. Since a large amount of renewable energy is required to realize the designed energy system, it is necessary to reduce the energy demand mainly in the industrial sector. Besides, in order to reduce costs, it is required to utilize electric vehicles by V2G and provide policy support for district heating systems in Japan. [ABSTRACT FROM AUTHOR]

Despite coal being one of the major contributors of CO 2 , it remains a cheap and stable source of electricity. However, several countries have turned to solar energy in their goal to "green" their energy generation. Solar energy has the potential to displace coal with support from natural gas. In this study, an hourly power flow analysis was conducted to understand the potential, limitations, and implications of using solar energy as a driver for decommissioning coal power plants. To ensure the results' robustness, the study presents a straightforward weather-driven scenario analysis that utilizes historical weather and electricity demand to generate representative scenarios. This approach was tested in Japan's southernmost region, since it represents a regional grid with high PV penetration and a fleet of coal plants older than 40 years. The results revealed that solar power could decommission 3.5 GW of the 7 GW coal capacity in Kyushu. It was discovered that beyond 12 GW, solar power could not reduce the minimum coal capacity, but it could still reduce coal generation. By increasing the solar capacity from 10 GW to 20 GW and the LNG quota from 10 TWh to 28 TWh, solar and LNG electricty generation could reduce the emissions by 37%, but the cost will increase by 5.6%. Results also show various ways to reduce emissions, making the balance between cost and CO 2 a policy decision. The results emphasized that investing in solar power alone will not be enough, and another source of energy is necessary, especially for summer and winter. The weather-driven approach highlighted the importance of weather in the analysis, as it affected the results to varying degrees. The approach, with minor changes, could easily be replicated in other nations or regions provided that historical hourly temperature, irradiance, and demand data are available. [ABSTRACT FROM AUTHOR]

In the carbon-neutral scenarios fixed by most developed countries, wind and solar resources play a significant role due to their substantial potential. Their instability can be mitigated through smarter designs of energy systems, including sector coupling and cross-border interconnections, which require detailed information on the spatial and temporal evolution of these intermittent resources. The present study aims at estimating the spatial–temporal energy potential of wind in Japan based on meteorological weather data. These data allow to analyze the potential of resources sharing to reduce power generation's lack and excess, even in such an isolated country due to its variety of climate conditions and local energy demand. The correlation skewness is introduced as a measure of the sites' uniqueness to identify important sites for the spatial distribution of capacity toward the efficient stabilization of supply at a national scale in a model-free fashion. [ABSTRACT FROM AUTHOR]

This study presents an approach for estimating the offshore wind potential of Japan. Bathymetry data (1 km mesh) and near shore wind speed data of the year 2018 were used to assess the potential. A turbine with a peak power of 10.6 MW was employed for the analysis. The potential was calculated for multiple regions. These regions are based on the service areas of the major electricity supply companies in Japan. Overall, the results show that Japan has the potential to produce up to 32,028 PJ electricity per year. The electricity demand of 2018 amounts to 3231 PJ. The potential is therefore large enough to cover Japan's electricity needs ten-times over. The capacity that could theoretically be installed amounts to 2720 GW, which is a multiple of the current worldwide installed capacity of 29.1 GW (2019). In addition to the huge potential, the regional assessment shows that the regions vary greatly in their potential; of all the considered regions, Hokkaido and Kyushu have the highest overall potential. [ABSTRACT FROM AUTHOR]

We consider the problem of short-term electricity demand forecasting in a small-scale area. Electric power usage depends heavily on irregular daily events. Event information must be incorporated into the forecasting model to obtain high forecast accuracy. The electricity fluctuation due to daily events is considered to be a basis function of time period in a regression model. We present several basis functions that extract the characteristics of the event effect. When the basis function cannot be specified, we employ the fused lasso for automatic construction of the basis function. With the fused lasso, some coefficients of neighboring time periods take exactly the same values, leading to stable basis function estimation and enhancement of interpretation. Our proposed method is applied to the electricity demand data of a research facility in Japan. The results show that our proposed model yields better forecast accuracy than a model that omits event information; our proposed method resulted in roughly 12% and 20% improvements in mean absolute percentage error and root mean squared error, respectively. [ABSTRACT FROM AUTHOR]

Advances in the introduction of fluctuating renewable energies, such as photovoltaics (PV), have caused power-system destabilization. However, stability can be improved if consumers change the way they use power, moving to time slots when the PV output in an area is high. In large cities in developed countries, where the types of distributed energy resources are varied, demand side management (DSM) in which consumers share power supplies and adjust the demand has received considerable attention. Under effective DSM that uses the latest information and communication technology to maximize the use of renewable energy, we believe that sparing use of appliances is not the only solution to address global warming. If behavioral change shifts the use of domestic appliances from one time slot to other time slots, we do not have to abandon the use of these appliances. The aim of this study is to determine the possibility of such behavioral changes in people in order to provide basic information for operating an effective DSM. To that end, we conducted a questionnaire-based survey of 10,000 households in Japan. We investigated the proportion of people responding to a request for a demand response (DR) under the given presented reward in time slots when DSM by DR is required. We also analyzed the factors influencing people's response to a request for a DR. Furthermore, based on the rewards likely to be achieved in the adjustable power market, we estimated how much adjustable power would be realized. [ABSTRACT FROM AUTHOR]