Wind and photovoltaic (PV) power systems are the most promising renewable energy resources. However, outputs of wind and PV power can change drastically, depending on the weather conditions. When the share of renewable energy generation increases, thermal power generation decreases, which causes a reduction of operating reserve they provide to the whole power system. Thus, provision of operating reserves is one important challenge that may prevent further growth of renewable energy. In this study, we examined the effects of using wind power to provide operating reserves to power systems. To do that we numerically simulated the operation of the ten balancing areas of Japan for 8760 hours, considering scenarios of high penetration of renewable energy. The results show that the provision of operating reserves from wind power can reduce the operation cost, CO₂ emission, and curtailment of wind power. In addition, we also show that, while the provision of operating reserve from wind power can increase curtailment of PV power generation, the contribution of renewable energy to the power system can be further improved if operating reserves not only from wind power but also from PV can be provided.

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Market power and unpriced carbon externalities are two failures that are common to wholesale electricity markets. We use a case study that is based on Japan’s wholesale electricity market to examine the impacts of addressing the former. Specifically, we compare Pigouvian taxes on carbon emissions and a renewable portfolio standard, which is an alternative indirect policy measure that is used commonly to reduce carbon emissions. We find that the benefits of Pigouvian taxes in reducing carbon emissions can be suppressed if market power is not addressed. This effect depends upon market structure, though. For the case of Japan’s electricity sector, this effect of market power is due to the industry being highly asymmetric. Carbon pricing increases the cost of carbon-intensive electricity-generation technologies. Lower-carbon generation technologies are held by firms with market power, which have incentives to withhold their capacity from the market to increase wholesale prices and their profits. As such, carbon pricing can result in high prices but muted carbon-emissions reductions. These impacts of carbon pricing are not observed if the wholesale electricity market is perfectly competitive.

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Despite electricity access becoming crucial for a community’s development, studies indicate that its universal access won’t be achieved by 2030, affecting mainly developing regions of the world. Off-grid microgrids are a popular solution to reach remote rural areas, however technical and economic challenges may hinder adoption efforts. This study aims to study the challenges that off-grid microgrid community projects face during deployment and operations, focusing on implementation and operation costs, technical performance, and sustainability to assess a project’s feasibility. Microgrid systems are also divided under different energy sharing structures, referred to as topologies, to consider the most common system layouts, evaluating off-grid stand-alone, centralized, and distributed operating systems in a case study for the northern territories of Guatemala. A respective scenario analysis and evaluation under economic and technical indicators is given on a sample of unelectrified communities from the region, considering different environmental, social, and geographical characteristics as part of the sampling process. Selected indicators include as economic indicators (1) initial investment costs and as technical indicators (2) system resilience and (3) system reliability. Each sample is evaluated under the three topologies, identifying the merits, demerits and enabling factors of each solution.

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This paper evaluates scenarios for achieving carbon neutrality using the bottom-up energy system model TIMES-Japan. The assessment framework includes the coupling of three energy models; an energy demand-supply model, a detailed power system model, and an energy demand model of residential and commercial sectors considering electrification and maximized implementation of energy conservation measures, by sharing technical variables via soft linkage. We evaluate scenarios for energy demand of the Japanese residential and commercial building sectors. From the results of scenario analysis, we showed the path of net-zero CO₂ emissions including negative emission technologies and carbon sink. Sensitivity analysis was conducted by changing the assumption of CO₂ mitigation scenario, CO₂ storage potential, availability of negative emission technologies, nuclear install constraint, wind install constraint and the introduction of a new zero-emission carrier called carbon-neutral LNG. Drastic changes in energy demand and supply and feasibility issues were discussed.

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Profound decarbonization requires restructuring a total energy system, while energy efficiency and fuel change for decarbonization are realized by electrification and CO₂-free or negative-CO₂ emission technologies. In order to evaluate and plan appropriate decarbonization pathways, it is necessary that we analyze the total energy system and the power system under appropriate demand prospect. Direct integration of an energy system model and a power system model is difficult because the required temporal and geological granularity of the analysis makes the calculation time too long. This paper presents results of a power demand and supply analysis under a soft link with an energy system model which uses a demand build-up model. The energy system model optimizes the long-term investment of a total energy system under different scenarios of decarbonisation. The power system model analyses a production simulation using a power demand and generation capacities from the energy system model, and evaluates storage operation, required capacities of generations, possible utilization of curtailed generation for synthetic energy production.

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