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Day-ahead electricity price forecasting (DAEPF) holds critical significance for stakeholders in energy markets, particularly in areas with large amounts of renewable energy sources (RES) integration. In Japan, the proliferation of RES has led to instances wherein day-ahead electricity prices drop to nearly zero JPY/kWh during peak RES production periods, substantially affecting transactions between electricity retailers and consumers. This paper introduces an innovative DAEPF framework employing a Convolutional Neural Network–Long Short-Term Memory (CNN–LSTM) model designed to predict day-ahead electricity prices in the Kyushu area of Japan. To mitigate the inherent uncertainties associated with neural networks, a novel ensemble learning approach is implemented to bolster the DAEPF model's robustness and prediction accuracy. The CNN–LSTM model is verified to outperform a standalone LSTM model in both prediction accuracy and computation time. Additionally, applying a natural logarithm transformation to the target day-ahead electricity price as a pre-processing technique has proven necessary for higher prediction accuracy. A novel "policy-versus-policy" strategy is proposed to address the prediction problem of the zero prices, halving the computation time of the traditional two-stage method. The efficacy of incorporating a suite of multimodal features: areal day-ahead electricity price, day-ahead system electricity price, areal actual power generation, areal meteorological forecasts, calendar forecasts, alongside the rolling features of areal day-ahead electricity price, as explanatory variables to significantly enhance DAEPF accuracy has been validated. With the full integration of the proposed features, the CNN–LSTM ensemble model achieves its highest accuracy, reaching performance metrics of R 2 , MAE, and RMSE of 0.787, 1.936 JPY/kWh, and 2.630 JPY/kWh, respectively, during the test range from 1 March 2023 to 31 March 2023, underscoring the advantages of a comprehensive, multi-dimensional approach to DAEPF. [ABSTRACT FROM AUTHOR]

As the global energy landscape transitions towards a more sustainable future, hydrogen has emerged as a promising energy carrier due to its potential to decarbonize various sectors. However, the economic competitiveness of hydrogen production by water electrolysis strongly depends on renewable energy source (RES) availability. Thus, it is necessary to overcome the challenges related to the intermittent nature of RESs. This paper presents a comprehensive techno-economic analysis of complementing green hydrogen production with grid electricity. An evaluation model for the levelized cost of hydrogen (LCOH) is proposed, considering both CO2 emissions and the influence of RES fluctuations on electrolyzers. A minimum load restriction is required to avoid crossover gas. Moreover, a new operation strategy is developed for hydrogen production plants to determine optimal bidding in the grid electricity market to minimize the LCOH. We evaluate the feasibility of the proposed approach with a case study based on data from the Kyushu area in Japan. The results show that the proposed method can reduce the LCOH by 11% to 33%, and increase hydrogen productivity by 86% to 140%, without significantly increasing CO2 emission levels. [ABSTRACT FROM AUTHOR]

The current energy trend indicates a strong thrust toward transforming renewable energy as a major power source. To achieve this mission, battery energy storage systems (BESSs) are indispensable. Although BESSs are expensive, cost reduction can be achieved by using BESSs for multiple purposes, such as load leveling, business continuity planning, frequency control, capacity market, arbitrage, and emergency power. In this paper, various applications of BESSs are classified. The possibility of achieving conflict-free combination of different applications is demonstrated. The total required energy storage capacity in Japan is estimated to be 150–200 GWh by 2030. The present status of NaS batteries for multipurpose use and new trends in battery-based businesses are introduced. [ABSTRACT FROM AUTHOR]

Managing energy-producing companies as well as managing the entire energy sector in the light of legal and environmental requirements requires a new vision, mission, and strategy. The paper analyses the strategies of energy enterprises. It is not enough now to produce energy and deliver it at appropriate, acceptable prices to consumers; it must be generated with the least negative impact on the environment. To achieve that plan, companies should cut the carbon intensity of their products by 20% by 2030, 45% by 2035, and 100% by 2050, using a baseline of 2016. To compared to 1990 levels, the greenhouse gas emission reduction target for 2030 should be increased to 55%. Bioenergy will represent 18% of total final energy consumption in 2050. Additionally, this requires the development of a long-term strategy that can force companies to completely reorganize their production or start a new operation and activities. A low-cost strategy or a competition strategy are insufficient, and it is necessary to look for new strategies that combine adaptation to the requirements of the external environment with the use of innovative solutions. The article analyzes the possibilities of implementing an innovative strategy based on biomass, especially bamboo biomass. The reduction in CO2 emissions of bamboo, taking into account life cycle emissions, can reach up to 85%. The novelty is to show the possibility of producing electricity by a large-scale power plant solely based on bamboo biomass on the example of a power plant located in the Tokushima prefecture, Japan. Another novelty is the fact that this article draws attention to the problem of burning bamboo in a power plant. The problem is that, as a result of burning bamboo, the clinker settles quite quickly. The study analyzes the selected ingredients for co-firing, which improve the combustion parameters of bamboo biomass (e.g., blended 20% bamboo with 80% pine or 30% bamboo with 70% tree bark). The importance of this research lies in the fact that it shows new innovative solutions in the energy sector that will help to achieve emission reductions. In addition, the article proposes to use eco-innovations and pay attention to eco-efficiency. Such solutions are an opportunity for ecological development through the use of bamboo as a fuel, which is classified as a renewable energy source by power plants. [ABSTRACT FROM AUTHOR]

Peer-to-peer (P2P) energy trading is gaining attention as a technology to effectively handle already existing distributed energy resources (DER). In order to manage a large number of DER, it is necessary to increase the number of P2P energy trading participants. For that, designing incentives for participants to engage in P2P energy trading is important. This paper describes a user-centric cooperative mechanism that enhances user participation in P2P energy trading. The key components of this incentive for participants to engage in P2P energy trading are described and evaluated in this study. The goal of the proposal is to make it possible to conduct economic transactions while reflecting the preferences of the traders in the ordering process, making it possible to conduct transactions with minimal effort. As a case study, the Higashi-Fuji demonstration experiment conducted in Japan verified the proposed mechanism. In this experiment, 19 households and 9 plugin hybrid vehicles (PHV) were evaluated. As a result, the study confirmed that prosumers were able to sell their surplus electricity, and consumers were able to preferentially purchase renewable energy when it was available. In addition, those trades were made economically. All trades were made automatically, and this efficiency allowed the users to continue using the P2P energy trading. [ABSTRACT FROM AUTHOR]

Microgrids are an attractive way to deal with energy depletion and environmental deterioration as well as grid pressure. However, the energy configurations of microgrids comprising various uncertain and variable resources are significantly sophisticated. Focusing on the peak shaving ability and carbon reduction effect of microgrids, this paper proposes a multi-criteria evaluation method that aims to maximize the comprehensive value of microgrids. To unify these criteria with different perspectives when solving the optimization problem, the peak shaving and emission reduction effects are converted into economies through peak load cost and carbon tax rather than using the weighting method. The results of a case study in Higashida, Japan obviously evidenced the superiority of multi-objective optimization. Although the improvement of the peak shaving ability and emission reduction effect was partially at the expense of system cost benefit, the total cost under multi-criteria was still reduced by 2.13%, which indicates that the balance and optimization of the economic benefit, peak shaving and carbon reduction were realized. The effect of each evaluation criterion on the optimal configuration was analyzed by comparing the optimization results under objective functions with different criteria combinations. High requirements for carbon reduction can promote the development of renewable energy, and peak shaving ability should be ensured by controllable and stable power generators. • Analyze the characteristics of grid load for five multi-types buildings in Japan. • Propose evaluation criteria including, economic, peak shaving and CO 2 emission. • Introducing peak load price and CO 2 tax, evaluation criteria are converted into cost. • The configuration of microgrid is optimized quantitatively under multi-evaluation. • Effect of each criterion is carried out by comparing different criteria combinations. [ABSTRACT FROM AUTHOR]

There was an unprecedented growth of SHP (small hydropower) in Japan during recent years because the government has provided a high FIT (USD 0.32/kWh) for SHP development projects of less than 200 kW. The public and private sectors are committed to harnessing this natural energy to achieve the renewable energy goal as well as to improve local communities social and economic conditions. This paper will discuss about renewable energy initiatives by a food corporation enterprise (FCOOP) based in Fukuoka prefecture of Japan to reduce their net carbon emissions. A detailed approach for social enterprises-based SHP development has been discussed which will be a role model concept for other social enterprises in Japan and in the world that are willing to reduce CO2 emissions. Also, this kind of project connects urban stake holders with local community where resources are available and it leads to development of the local community living standards. As a demonstrated example, a case study of a 20 kW SHP installed in Japan by a FCOOP has been discussed. [ABSTRACT FROM AUTHOR]

With Japan's current plans to reach a fully decarbonized society by 2050 and establish a hydrogen society, substantial changes to its energy system need to be made. Due to the limited land availability in Japan, significant amounts of hydrogen are planned to be imported to reach both targets. In this paper, a novel stochastic version of the open-source multi-sectoral Global Energy System Model in conjunction with a power system dispatch model is used to analyze the impacts of both availability and price of hydrogen imports on the transformation of the Japanese energy system considering a net-zero emission target. This analysis highlights that hydrogen poses a valuable resource in specific sectors of the energy system. Therefore, importing hydrogen can indeed positively impact energy system developments, although up to 19mt of hydrogen will be imported in the case with the cheapest available hydrogen. In contrast, without any hydrogen imports, power demand nearly doubles in 2050 compared to 2019 due to extensive electrification in non-electricity sectors. However, hydrogen imports are not necessarily required to reach net-zero emissions. In all cases, however, large-scale investments into renewable energy sources need to be made. • Hydrogen poses a valuable resource in certain non-power sectors of the energy system. • For power generation, hydrogen only plays a minor role as peak-load technology. • Without hydrogen imports power demand doubles in 2050 compared to 2019. • Importing hydrogen is not necessarily required to reach net-zero emissions. • Extensive investments into renewable energy sources need to be made in all cases. [ABSTRACT FROM AUTHOR]

Hydrogen is currently receiving significant attention and investment as a key enabler of defossilised global energy systems. Many believe this will eventually result in the international trade of hydrogen as a commodity from countries with significant renewable energy resources, for example New Zealand and Australia, to net energy importing countries including Japan and Korea. Japan has, since 2014, been actively exploring the components of the necessary supply chains, including the assessment of different hydrogen carriers. Public/private partnerships have invested in demonstration projects to assess the comparative merits of liquid hydrogen, ammonia, and organic carriers. On the supply side, significant projects have been proposed in Australia while the impending closure of New Zealand's Tiwai Point aluminium smelter at the end of 2024 may provide an opportunity for green hydrogen production. However, it is also evident that the transition to a hydrogen economy will take some years and confidence around the timing of supply and demand capacity is essential for new energy infrastructure investment. This paper reviews the expected development of an export market to Japan and concludes that large scale imports are unlikely before the late 2020s. Comparative evaluation of the energy efficiency of various hydrogen carriers concludes that it is too early to call a winner, but that ammonia has key advantages as a fungible commodity today, while liquid hydrogen has the potential to be a more efficient energy carrier. Ultimately it will be the delivered cost of hydrogen that will determine which carriers are used, and while energy efficiency is a key metric, there are other considerations such as infrastructure availability, and capital and operating costs. [ABSTRACT FROM AUTHOR]