This study attempts to show processes controlling the geochemical evolution of Menengai geothermal system using 1-D reactive transport model. The model uses geothermal fluids, modeled from wellhead discharge chemistry to obtain the initial aquifer fluids. The resulting fluid is then injected into the model at the bottom and allowed to ascend through a porous media as the ‘parent’ fluid. Chemical data from a nearby water borehole was used as initial medium fluid while pressure and temperature information taken from well downhole measurements. The reservoir rocks are predominantly peralkaline, silica-oversaturated trachytes, with a few lenses of tuffs, rhyolite, and basalt, thus, the initial mineral assemblage of the model taken to be of the trachytic composition. The simulation was performed using TOUGHREACT v2, and the model was calibrated using field-observed hydrothermal minerals. This study demonstrates the relationship between fluid flow, chemical reactions, and mass transport in a peralkaline salic volcanic complex, a caldera-hosted geothermal system with a view of explaining the occurrence of hydrothermal minerals in up-flow zones in such systems.

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ECLIPSE Geothermal, a fully functional geothermal numerical simulator, has all the elements necessary for geothermal reservoir modeling (heat, mass, gases, tracers, and air). We have performed validation testing using the Stanford geothermal test cases (which were used to validate all existing geothermal simulators during their early development). This numerical simulator matched each test problem as accurately as any geothermal simulator currently available. Its parallel processing capabilities can provide a 40x computational speed increase. ECLIPSE Geothermal can be used to model all types and sizes of geothermal reservoirs encountered so far in the industry.

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The authors tried to construct a thermal water flow model of the Futsukaichi Hot Springs area, one of some non-volcanic and low-enthalpy geothermal systems in Fukuoka Prefecture, Kyushu, Japan, by using numerical simulation to explain the conceptual model of this area, which is based on the previous research results. The conceptual model explains that the origin of Futsukaichi hot spring water is the rain water at the high-elevation areas, and the water permeates and reaches to the depth of about -3 to -4 km asl with heating by the ground, and finally it ascends to the ground surface through the fracture zone of an active fault. And the most suitable numerical model also shows the same water flow. In addition, there is no special water source and no special heat source to create the Futsukaichi hot springs in this numerical model. Namely, this numerical model is a comprehensive explanation of the non-volcanic, low-enthalpy geothermal system in the Futsukaichi Hot Springs area.

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Ulumbu is a geothermal field located in East Nusa Tenggara, which has been generating electricity of 10 MW. To accommodate a better understanding of the geothermal system characteristics and the unexplored area of the prospect, it is important to perform reservoir modeling study. A completely improved natural state model of Ulumbu geothermal field is discussed in this paper. The newer model consists of several improvements in terms of model structure and model validation. The improved natural state model can represent more accurate modeling results and can overcome the limitations of the previous version.

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A power generation system using the heat source from hot spring water was proposed. The considered system consists of two cycles. These 2 cycles combined as a binary system. For the environmental safety, water is used as working fluid instead of the low boiling point organic substance. Since a low temperature heat source is used, a vacuum is maintained inside the working fluid line which enables the working fluid to evaporate even at a low temperature. Low pressure Rankine cycle using the steam table and the influence of the working fluid pressure and the turbine inlet steam quality was clarified by solving the pinch point constraint in the evaporator.

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The municipality of Isa is located in the southern part of Kyushu Island, and it is considered one of the wealthiest places in Japan because one of the most important gold mines is found in this area, Hishikari mine. Until now, the geothermal resource has not been used for power generation purpose although Geological Survey of Japan had carried out some preliminary geothermal assessments, which show that the power potential density is around 20 kW/km2. To calibrate the previous value, first, this study pretends to analyze the gravity data for figuring out geothermal reservoir border and the assessment of geothermal potential. For this purpose, an area of 10 x 10 km was selected. The Bouguer Anomaly result shows a high value in the center which extends 5.61 km2 wide and represents the possible geothermal reservoir. Therefore, using this value, the power potential assessment was 107.6 kW/km2 for 20 years.

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To study the occurrence conditions and locations of geothermal bodies in Eburru geothermal field, Kenya, magnetotelluric investigation was conducted to detect promising zones for geothermal development by studying the detailed subsurface resistivity distribution on parallel profiles. In particular, delineating the locations of faults and fracture systems by studying resistivity discontinuities, and the cap rock zones of geothermal reservoirs by studying low resistivity zones at relatively shallow depths, are important in selecting future drilling targets.MT data analysis was done to derive a dataset suitable for defining the resistivity model of the Earth from the observed MT data. Dimensionality analyses demonstrated that the MT data can be interpreted using two-dimensional approaches, but some localized 3-D effects are seen. The inversion of data into resistivity model was performed using Occam 2D and the resultant 2-D resistivity sections were interpreted as to identify the components of Eburru geothermal system. The four profiles analysed revealed a structure which can be interpreted as potential path way of low resistivity used by geothermal fluid to migrate to the surface. An exploratory well drilled near the structure in Profile 2 confirms the occurrence of high temperature.

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Fractures in geothermal reservoirs can be located in three dimension by the microearthquakes observation as their hypocenter locations. However, microearthquake hypocenter location accuracy is depended on the underground seismic wave velocity structure which has a strong heterogeneity in the geothermal areas. Calibration tests using detonation shots in deep wells can compensate the heterogeneity. Field tests conducted in the Ogachi Hot Dry Rock (HDR) experiment showed that artificially created fractures were located accurately with 10 to 20 m errors by station correction values which were obtained by calibration tests at about 1,070 m depth.

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In 2012 and 2017, temporary seismic networks were installed at a Kijiyama-Shitanotai geothermal field, Akita prefecture, Japan. Microseismic data was gathered using these networks for three months in each case. The networks were located in different areas of the geothermal system. The data was analyzed to identified of 499 local microearthquakes in 2017 and 475 in 2012 (a total of 974). From this data a velocity model was derived, and the earthquakes located. The shear waves recorded were analyzed for shear wave splitting (SWS). The SWS splitting results were used to derive a three-dimensional crack density model and polarization direction. The SWS result indicates a high in crack density and NE striking fractures in the north of the seismic network and NW striking in the south.

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Despite having 40% of world’s potential for geothermal power production, Indonesia exploits less than 5% of its own geothermal resources. This paper explores the reason behind this lagging development and highlight the technical and non-technical barriers that includes (i) insufficient technology development or access to new technological innovations (ii) delays caused by conflicts in regulatory environment (iii) capacity of the local governments in managing the point source nature of the local resources (iv) absence of incentives at the energy sectoral level and (v) historical subsidy program that disincentives investments in new technologies such as ground source heat pump (GSHP). This barriers are situated against development in New Zealand to identify solutions. This paper concludes that creating a stable and predictable policy environment in renewable energy development is critical. Supporting open, competitive and demand driven innovations would help to sustaina renewable energy industry in Indonesia

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In high temperature geothermal power application, it is essential to maintain the well integrity despite of aggressive nature of geothermal fluids and high temperatures adversely affecting the conditions of well elements. To extend the lifetime and performance of such wells, the GeoWell project commenced in 2016. The project aims to develop and test reliable, cost effective and environmentally safe completion and monitoring technologies to reduce risk and operation costs of high temperature (⁓450°C) geothermal wells. As part of this project, this study outlines a conceptual framework for risk assessment and management of high temperature geothermal wells.

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Geological Survey of Japan, AIST, had organized a groundwater research project. The project released hydro-geological map including latest scientific information of the Chao-Phraya Plain, Thailand and the Red River Delta, Vietnam. A sub-project, entitled “Development of Renewable Energy for Ground-Source Heat Pump System in the CCOP Regions”, started in April 2013.The CCOP groundwater database created in the Phase III will contribute not only to groundwater management but also to the development of the maps suitable for GSHP system in CCOP member countries.

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Though, ground Source Heat Pump (GSHP) has been widely used amongst many countries, this system still has a limitation in some places, particularly in the tropical zone because of its hotness of climate condition and subsurface temperature. Therefore, with an attempt to install GSHP system in the tropical zone, the central Thailand has been initiated in the mode of cooling system. Two sites of Chulalongkorn University were selected to study i.e.Bangkok and Saraburi in the different forms. At Bangkok site, the vertical loop was installed due to areal limitation by putting HDPE tubes into two 50-meter-deep boreholes for heat exchange from ground surface. As regards to comparing electricity consumption between GSHP and conventional air conditioning, it is found that the electricity consumption of GSHP air conditioner was reduced at least 30%, but the price of installation is still high. Furthermore, GSHP system at Saraburi site was installed in the form of horizontal loop by putting 300 meter-long HDPE tube into 1-2 m deep borehole from the ground surface. The comparison on the efficiency performance of both systems is underway. Most importantly, the GSHP system can be utilized in the area of tropical zone efficiently especially in Thailand.

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Thermal Response test (TRT) was carried out at a borehole heat exchanger (well depth: 100 m) at AIST Tohoku to evaluate suitability for Ground-Source Heat Pump (GSHP) System. During the test, an optical fiber sensor was inserted into the U-tube to calculate apparent thermal conductivity by depth. Apparent thermal conductivity of Quaternary were larger than that of Neogene. Apparent thermal conductivity obtained by TRT was compared with thermal conductivity of core samples in Neogene. There is not much difference between them. Quaternary are expected to be more suitable for GSHP system utilizing groundwater flow than Neogene.

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A high-efficiency aquifer thermal energy storage cooling and heating system with solar collector installed in Yamagata City was constructed and put into operation. In actual operation, 100% of pumped groundwater could be injected. In the heating operation in the winter of 2016-2017, the number of operating days was 187, and 83,420 MJ of cold energy was stored in the aquifer. In the cooling operation in the summer of 2017, the number of operating days was 125 days. The combined use of solar collectors was started from the time of the cooling operation, and 103,078 MJ thermal heat was stored in the aquifer by passing the groundwater after heat exchanged in the primary through the solar collectors (heat collection area: 160 m2). In the heating operation between 2017 and 2018, the number of operating days was 201, and 159,075 MJ of cold heat was stored in the aquifer by using this solar collector in combination. Effects of the aquifer heat storage were observed at the pumping temperatures during operation, and the COP and SCOP were improved by about 0.7. As described above, the system is called a highly efficient system because it can efficiently utilize the heat storage in the aquifer and the heat storage effect by using the solar collector in combination. A three-dimensional groundwater flow heat transport model was constructed based on the boring data, and the simulation was carried out. Simulations were carried out using the operation data as input data, and the transition of the temperature change in the aquifer due to the operation of the ATES system was visually reproduced three-dimensional groundwater fluidized heat transport simulations have shown that the heat stored in the aquifer can be effectively utilized for subsequent heating or cooling operations.

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The city hall of Sakata was designed as environmentally friendly building. Ground Source Heat Pump (GSHP) system and Aquifer Thermal Energy Storage (ATES) system are the significant features of the building. The heat exchanger of GSHP system has been installed in the Cast in-place Concrete Piles. The ATES system is operated as road heating equipment in the winter, and as cooling device of heat source system for air conditioning in the summer. So the heat source system, with is combined operations yields the high performance. This paper describes the outline of the building plan, heat source system and the construction process.

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The first stage construction of the city hall of Sakata was completed in December 2015, and the second stage construction was completed in June 2017. It is currently in operation and heat source system and air conditioning system have been operating smoothly. In addition, the heat source system satisfies the expected performance. This paper describes the outline of the thermal response, the results of heating operation in the winter season and cooling operation in the summer season.

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This paper presents a new heat exchanger of ground source for renewable energy having with a champion data in the world wide on the temperature rising during constant heat load according to the thermal response test method. The new technology is completed by Virtual Harmony. The technique of the new heat exchanger is registered a patent in Japan and the patent is applied international patent. The patent technique is a horizontal type, not a borehole type, based on the principal heat transfer engineering theory. Those are larger heat transfer area and bigger thermal conductivity. The patent technique will produce economic rationality, 20-40% investment of the current technique and under 50% running cost of the current technique. We aim and is challenging to build non-carbon society contributory to solve global warming problem with you.

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In this paper, the design procedure of hybrid heat source heat pump system coupling of ground-source and air-source is discussed at the early design phase of air-conditioning system for a commercial building. A design procedure for determining capacity balance of ground-source and air-source is presented, then the design parameters should be considered in the design procedure are described. Based on the proposed design procedure, the case study is conducted. The results of case study show that the capacity balance of heat pump coupling ground-source and air-source is influenced by the amount of peak load of a building and a building coverage ratio. Also, the maximum capacity balance would be considered in the case of conceivable condition is provided, it could be a criterion while a system designer define a capacity balance of hybrid heat source heat pump system.

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In order to investigate the effect of the ground surface coverage on the horizontal ground heat exchanger (HGHE), a long-term monitoring of ground temperature and thermal response tests (TRTs) were conducted using three HGHEs under lawn, soil and asphalt, respectively. The monitoring showed that the ground temperature behavior of the lawn was most stable. The TRTs showed that the temperature increase per unit heat exchange rate of the lawn was the lowest among the other coverages. Long-term simulations in heating and cooling operations using HGHE simulation models showed the efficiency of HGHE under lawn was improved in the cooling period.

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The study area ‘Hatchobaru-Otake geothermal field’ is located west of Kuju volcano in the central Kyushu island of southwest Japan. There are three power plants operating from the geothermal field such as Otake plant generating about 12.5 MW peak of power from 1967, Hatchobaru unit 1 is generating 55MW peak of power from 1977 and Hatchobaru unit 2 generating 55 MW from 1990. The prime objective is to explore and monitor the thermal status of the Hatchobaru-Otake geothermal area using night time ASTER satellite thermal infrared images from 2009 to 2017 in this study. Split-window algorithm used for land surface temperature measurment and Stefan-Boltzmann equation was used for radiative heat flux estimation in this study. Local AMEDAS meteorological data was used for atmospheric transmissivity derivation for the ASTER image acquisition time of the study area. The result showed that the radiative heat loss was about 30 MW, 40 MW and 0.4 MW respectively in 2009, 2013 and 2017. The higher anomaly area of radiative heat flux was obatined in 2013 and lower in 2009.

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Ground Source Heat Pump system (GSHPs) has a possibility to reduce environmental load in Southeast Asia. However, GSHPs has not been introduced in Southeast Asia except experiment facility. In order to know effectiveness of GSHPs in Bangkok, life cycle assessment and cost evaluation was conducted to compare with Air Source Heat Pump system (ASHPs). As a result, life cycle environmental load and economic cost of GSHPs was less than that of ASHPs. Therefore, the result showed that the introduction of GSHPs in Bangkok leads to reduction of environmental load and have an advantage in terms of economic point of view.

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This paper presents the measurement and analysis results of the cooling performance of a ground-source heat pump system using surface water heat exchanger (SWHE) submerged in an artificial pond. In order to measure the performance of the system, we installed monitoring equipment including sensors for measuring temperature and power consumption, and then measured operation parameters. The results from the thermal performance test for the SWHE showed that the temperatures at the outlet of the SWHE and at the inside of the pond were affected by outdoor air temperature. In addition, the results showed similar variation trends on temperatures; however, the peak temperatures of the SWHE were somewhat greater than those of outdoor air, due to the thermal capacity of the pond. Analyzing the cooling performance over the measurement period, the average coefficient of performance (COP) of heat pump in cooling mode was found to be 5.71, while that for the entire system was 2.99.

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Wind power capability has increased drastically in the last decade worldwide, with its strong growth expected to continue over the next several decades. Wind power output fluctuates according to weather conditions. Accordingly, the more wind power capability grows, the larger the impact of fluctuations in wind power output becomes in electric power systems. To mitigate fluctuations, control of wind power output is one of the most cost-effective options, because some control functions are already included in the latest wind turbine generators. However, such control involves inevitably energy loss, where there is a tradeoff between energy loss and the degree of control. Using high-resolution data of wind power outputs in three balancing areas in Japan, we mitigate very-short-term and short-term fluctuations using these control capabilities. We also discuss the energy loss.

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This study developed a simplified Unit Commitment model to evaluate the future effects of high penetration of variable renewable energies (VREs) on the supply-demand balance of the western Japan grid in 2030. The utilization of the daytime-pumping mode of pumped storage hydropower, inter-regional transmission, and heat pump systems (HPs) and electric vehicle (EV) charging can accommodate a major portion of the power supply from VREs in the High case. The hourly activation of HPs and EV charging must be well adjusted with reduced operation of coal power units and levels of PV output. Control reserve activations through inter-regional transmission lines are recommended.

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The low temperature of Liquefied Natural Gas (LNG) makes it a valuable exergetic source. However, cold from LNG-regasification is rarely recovered. On the other hand, the integration of renewable energy sources in LNG cold recovery systems might be a promising option in the transition to a greener energetic model. In this paper, we analyze a polygeneration plant that exploits LNG exergy in cascade to produce simultaneously electric power and refrigeration with the integration of solar and biomass energy. The plant produces an equivalent electricity saving of 91.4 kWh/t-LNG and avoids an annual emission of 36,078 tons of CO2.

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The 60MWh vanadium flow battery system was installed in Minami-Hayakita substation of Hokkaido Electric Power Co., Inc. (HEPCO), and started operation December 2015, to demonstrate application of the storage battery as a dispatchable power source like fire plants and hydro plants. In commissioning tests, initial characteristics of the flow battery system, such as energy capacity, system efficiency, and response time, are confirmed. These results satisfied the specification of the system. This system has been operated to demonstrate various types of control modes such as load frequency control, compensation for wind power and PV output fluctuation, control for countermeasure against over generation, and so on. In periodic evaluation, it is confirmed that there is no deterioration of energy capacity and system efficiency, which are main performance parameters, for these 2 years of operation.

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A large-scale battery energy storage system for the Nishi-Sendai Substation located in the western part of Sendai City in Miyagi Prefecture, commenced operation in February 2015. The demonstration project has been launched as a new approach to frequency changes caused by weather-dependent power fluctuations resulting from the increasing use of renewable energy sources such as wind and photovoltaic systems. It is expected to contribute to the stabilization of electricity generation and the further expansion of renewable energy sources.

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Voltage fluctuations caused by output fluctuations of renewable energies are becoming an issue where a large amount of renewable energies connect to a localized area. We have developed a reactive power control system which calculates reactive power command in order to suppress voltage fluctuations in a localized area utilizing a reactive power output function of a large-capacity battery system. In February 2016, the system was installed in the Minami-Soma substation and demonstration experiments started. The installed system effectively suppressed voltage fluctuations.

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NGK has developed a sodium sulfur battery (NAS battery) for load leveling applications, allowing the grid to deal with increasing peak. The recent growth in environmentally friendly renewable energies causes network instability. A secondary battery based energy storage system is seen as one of the strongest solutions to stabilize the network while improving the efficiency and usability of these renewable energy technologies. The NAS battery features long duration discharge, compactness, and a long lifespan of 15 years. The capacity for long duration discharge is one of the most notable features of this technology, a feature which becomes more important as renewable energy generation increases.

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When wind power companies trade their electricity at an electricity market, strategy to cope with forecast error is essential to maximize their profit. An energy storage system is one of solution, however, there are no enough discussion about state-of-charge target even it is important factor to minimize cost. The authors proposed a method to obtain ‘SOC target curve’. By numerical simulation, the SOC target curve’ depends on ratio of imbalance fee divided by curtailment cost have been obtained. By the simulation, about 20% of the cost can be reduced compared to fixed SOC target. The proposed method is verified by the numerical simulation.

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A large scale battery energy storage system, which can output power at MW-order, has many Power Conditioning Systems (PCSs). The authors have proposed an active power dispatch method for PCS. The active power distribution method uses information of Need of Charge (NOC) and Maximum Efficiency Power point (MEP), and the method is called NOC-MEP method. The NOC-MEP method showed higher charge/discharge efficiency than the conventional method in which active power is equally distributed to each PCS. The NOC-MEP method has been installed in the battery system at Nishi-Sendai substation of Tohoku Electric Power Co. Inc. This paper reports the charge/discharge efficiency of the battery system at Nishi-Sendai substation, which employs the NOC-MEP method.

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The reform on power systems and the explosive growth of renewable power sources make it more difficult to maintain sufficient capacity of LFC, Load Frequency Control for stable power systems in the near future. On the other hand, EVs, electric vehicles are promoted to decrease CO2 emissions. Since EVs have batteries, the concept of connecting vehicles to power grids for LFC is attracting our attention. In this research, we assume a community which introduces EVs to provide transport services and investigate the system of using EVs for LFC through actual experiments and computer simulations.

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This paper proposes an optimal scheduling method of aggregated demand-side batteries for demand response. Demand-side batteries are needed for multipurpose operation including peak-shave and demand response (DR) by energy resource aggregators. The method can make optimal operation schedule of the batteries achieving the multiple purposes simultaneously using mathematical programming when DR time period is known. A Numerical simulation for three customers shows that the proposed method can generate an effective operation schedule.

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An efficient energy management tool is required to control flexibility the home/building energy devices such as photovoltaic (PV) power generation and storage battery (BT), etc. In this paper, we propose a new energy management tool which consists of PVs and BTs, DC loads, their connection line DC power bus, AC loads via inverter, and connected/unconnected to distribution line. 24-hour energy management system simulation is carried out to verify the performance of the proposed tool by MATLAB/Simulink SimPowerSystems. We confirm that the output of the PV, the charge/discharge operation of the BT, the consumption of the AC load is successfully operated.

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In this paper, we show the result of building and simulating a model that can optimally operate electric power supply by a system combining photovoltaic power generation and storage battery. Especially focusing attention on storage batteries, by solving the objective function that minimizes electricity charges of customers by using the internal temperature and life characteristics of the storage battery as constraint conditions, an optimal solution is obtained. Compared with the case where the constraint condition is not taken into consideration, although the electricity charge increases, it is evaluated that the system can be used stably for a long time.

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The pilot plant of CAES has maximum power for charge and discharge of 1,000kW and energy storage capacity of 500kWh and 52 of compressed air tanks have a capacity of 30.5m3. They are used at a pressure between 0.30 to 0.93 MPaG. Via adjustment of control systems and official inspection, the construction has completed in the end of April, 2017. Waseda University and The Institute of Applied Energy operate the plant for 2 years from FY2017. Characteristics of the plant are measured at first followed by validation of newly developed control technologies using wind power prediction information.

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In this paper, the new concept of micro-grid called Expandable Micro-Grid Cluster (EMGC) for electricity Infrastructure and EMGC’s construction and operation support tool called Grid of Grids Optimal Designer (GGOD). EMGC is an autonomous cluster group wherein clusters can generate and consume power. Moreover, powers are transferred among clusters when clusters require powers and connected clusters possess surplus of power. GGOD supports optimal construction and operation of EMGC and the minimization of power facilities and operation costs can be calculated. Three key technologies for the realization of EMG Care discussed: geospatial facility expansion planning, and bad data detection and suppression.

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Karimunjawa is a small and remote archipelago in Indonesia. It has a population of 9,242 people which are the main profession as fishermen. They have the main problem in ice block’s provision to keep their fish fresh so that they can sell it at a good price. Also, like another remote island, they face lack of electricity because electricity in Karimunjawa is mainly supplied from the diesel-based generator. This study aims to provide a smart micro-grid system based on local renewable energy resources which have to provide independent and sustainable energy to supply fishermen’s ice maker machine. Based on design and optimization using HOMER software, sustainability of fuel, and operational consideration, for 2kW ice maker machine, we get the capacity for each component is 5 kWp PV, 3 kW bio-based diesel engine, 5 kW converter and 16 batteries. And from the performance evaluation, it is can run smoothly and supply power to the loads without trouble.

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Myanmar’s growing economy has received increasing attention in recent years. However, low electrification hampers economic growth. For greater electrification, both centralized (main grid extension) and decentralized approaches should be considered. We compared distributed micro-grids powered by solar photovoltaics (PV) and conventional diesel as electrification options by calculating the levelized cost of electricity (LCOE) based on primary data collected through interviews and field surveys in Myanmar. The results showed that diesel’s LCOE was not low because of higher fuel prices in off-grid areas and a PV system with batteries was cost-competitive. Increasing daytime electricity demand can improve PV operation efficiency.

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As regards the isolated microgrid adopting the energy storage system (ESS) as its swing bus, when the actual renewable energy generation deviates from the forecast result, ESS provides this difference spontaneously. It turns out that ESS will deviate from scheduling on the state of charge (SOC), even shut down. In this study, a real-time dispatch scheme is proposed to amend the errant SOC. When the SOC error is considerable, this dispatch will be activated to compensate the additional energy afforded by ESS on the base of minimizing short-term generation cost. Therefore, the microgrid will keep running steadily and economically.

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The economic and environmental problem due to fossil fuel usage as an energy source is urgently needed to be solved. In countries like Indonesia, which is located in equatorial area, the abundant source of renewable energy is one of the solutions that can be utilized to counter this issue. However, 89% of total electricity consumption in Indonesia use fossil fuel, while public sector consumed 6% of Indonesia’s total electricity consumption annually. Converting some of the public sector source of electricity usage, streetlight for example, can help the government a great deal. Although some of the streetlights in Indonesia have already been remodeled to PV streetlights, problems arise when the inconsistency of sunlight happens. Combining PV and Wind turbine as electricity source is an alternative to solve this issue, and is becoming a trend nowadays. Due to small wind speed in Indonesia, finding the best turbine type is a major obstacle for developer. This study’s aim is to offer the best type of wind turbine in urban Indonesia’s area, and to recognize the proportion of PV and wind turbine energy support in the system. Based on ANSYS CFD 17.0, the best wind turbine’s geometry for urban area in Indonesia is Savonius Wind Turbine with twist angle of 90° and aspect ratio of 2. Based on Indonesian’s street standard, the streetlight is 3 m height, using 10 W of LED light. To support this light, the source is using 160 Wp PV systems, combined with a Savonius Wind Turbine of 2.5m heights and 1.25m diameter. The average energy given by the PV panel is 214,1 Wh, while from wind turbine is 5,8 Wh.

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Peak demand shaving is an effective way for reducing electricity bills. This paper focuses on an approach utilizing electric power interchange between areas and analyzes its effect from the viewpoint of peak power reduction. The usefulness of power interchange for a certain area has been demonstrated in previous researches, but the general effect has not been verified. In this paper, simulational experiments are performed using various load data, so that the amount of peak demand reduction is evaluated from the viewpoints of the shape of a load curve and the timing of the peak occurrence date.

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This work investigates two different motor drive technologies, switched reluctance motor (SRM) and induction motor (IM). They are designed optimally to meet the desired performances for high speed electric scooters (e-scooter). Steady-state and transient thermal behaviors must be considered in order to study performance of motor cooling system. A common simplified lumped-parameter thermal model for SRM and IM are described. Finally, two driving cycles are simulated, a standard European urban driving cycle ECE15 and a more realistic cycle, Bangkok driving cycle. As a result, two motors can withstand rated torque condition. Their steady-state winding temperatures are well below insulation temperature limit. Their transient thermal behaviors are very satisfied on both standard driving cycles.

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Since the introduction of the Feed in Tariff (“FIT”) system in Japan, there has been a rapid increase in the adoption of photovoltaic power generation systems (“PV”). Issues have arisen that need to be addressed so that the adoption of renewable energies may be further increased. Tokyo Electric Power Company Holdings, Inc. (“TEPCO”) has been developing and verifying, as a means for resolving issues, smart inverters for photovoltaic power generation systems that have multiple functions contributing to system stabilization as well as a distributed energy resource management system that remotely monitors and controls the smart inverter.

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Due to rapid penetration of renewable energy sources (RES), it becomes more important to assess the feasibility of power system operation under limited controllable resources. This paper proposes a new method, “Robust Power System Security,” to evaluate the existence of the feasible region under uncertainties. Predicted RES and demands with their confidence intervals are specified to formulate a problem for the evaluation of the size of the worst-case feasible region. The method computes the degree of system security for the worst case. We demonstrate a linear constrained dynamic economic dispatch to verify the effectiveness of the proposed method.

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Recently, electric power systems face difficulties in system operations due to rapid increase in intermittent renewable energy sources (RESs), such as photovoltaic power generations (PVs). Reduction of controllable resources also yields concerns about system reliability issues. This paper focuses on a new generation dispatch method for mitigating the irregularity associated with RESs. The advantage of the proposed method is to realize both high accuracy of the solution and reduction of the computational burden by using a piecewise linear approximation. The simulation of the proposed unit commitment and the economic load dispatch are carried out to evaluate the performance of the robust supply and demand controller.

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In Japan, there are subjects that surplus power and regulator shortage by introducing a large amount of photovoltaic in recent years. As the results, it is necessary to suppress the output of photovoltaics to maintain supply and demand balance. It has been proposed that output control and utilizing electric vehicle for improvement of these issues. However, these preparations are not enough to solve those issues. In this study, we propose surplus power transaction system by using blockchain and smart contract. In addition, we measured transaction fee and elapsed time in proposed system.

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Under the large penetration of photovoltaic systems, the voltage control in a distribution system will contain a difficulty due to the fluctuated reverse power flow, so that the appropriate deployment of voltage regulators is required to suppress the voltage violation. However, derivation of an appropriate long-term deployment plan of voltage regulators is a difficult task because of the uncertainties in spatial-temporal penetration scenario of the photovoltaics systems connected to the distribution system. This paper focuses on a simple approach for deploying step voltage regulators considering uncertainties in penetration transition of photovoltaic systems in order to discuss the necessity of long-term plan. The impact of long-term deployment plans is evaluated by numerical experiments.

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In recent years, electric vehicles (EVs) have attracted attention as power storage devices. In this study, the house has residential PV, stationary battery and EV. We examined the self-consumption rate is improved by introducing the V2H in the house. In the house with V2H installed, restriction on SoC of EV battery was set before driving, and storage battery operation was carried out in consideration of the convenience of EV users. Consequently, even if the capacity of the stationary storage battery is halved, the self-consumption rate was improved more than 1.09 times by V2H introduction.

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