We developed the design and evaluation method of Microgrid energy systems for residential area, with electricity sharing using battery and electric vehicles. Using half-hourly demand data from smart-meter, which is widely provided after deregulation of residential market in 2016, we simulate how to manage electricity using battery and electric vehicles dynamically, and evaluate the impact of electricity sharing. We calculate leveling effect of peak of demand by gathering several households and found that the peak of demand is leveled to 2kW/household. Based on this method, we can evaluate ratio of usage of renewable energy generated in the residential area, the amount of CO2 emssion reduction, and cost reduction to provide energy. By the method we report in this paper, we can find the way to lead to the design of microgrid energy systems, even though the cost of each equipment changes in the future. Energy systems designed in this paper is planned to install in Saitama area in Japan, and this method is feedbacked by gathering further actual data to be more practical.
This paper presents the bifacial photovoltaic (PV) module for power system operation. The main proposal is a vertical installation set of the bifacial modules, in order to mitigate the restriction of PV interconnection due to the duck curve problem. The installation set shows shifted and pushed peak and bimodality in the power generation curve. The characteristics are clarified by detailed irradiance model calculation. It has a possibility to reduce the mismatch between generation and load by shifted and pushed peak characteristics. Moreover, the bimodality generation curve can shorten the charging/discharging cycle of the energy storage battery and it may reduce the storage capacity. However, the massive installation of the bifacial module has not been evaluated in the power system. The unit commitment (UC) problem is the most suitable framework in order to evaluate proposed installation set of the bifacial modules. Therefore, in this paper, Netload curve with bifacial generation profile applied to the UC problem. Verification by solving the UC problem clarified the effectiveness of a simple method which is bifacial PV module installation set from viewpoints of PV installation capacity, total PV generation, installation cost, fuel cost, daily operation cost.
Dehumidification using a desiccant air conditioner that has high possibility of reusing exhaust heat is effective in reducing energy consumption. Furthermore, it significantly improves human thermal environment, especially in humid countries such as Japan. Thus, the necessity to install desiccant air conditioners is increasing with the need to reduce energy consumption. In this study, to evaluate thermal environment using a desiccant air conditioning system, we carried out subjective tests both in a demonstration house in Hokkaido and an artificial climate chamber. The measured values and subjective questionnaire reveal that effectiveness of desiccant air conditioning on the indoor environment and human thermal comfort. In terms of room temperature, humidity and human thermal environment, the desiccant air conditioning showed almost the same level of performance as the space cooling by a commonly used air conditioner (set temperature 28°C). Regarding the thermal sensation of subjects, the field tests in the demonstration house showed the superiority of the desiccant air conditioning over the conventional air conditioner. In the tests in the artificial climate chamber, the superiority of the thermal environment was shown in the order of space cooling (26°C), desiccant air conditioning, space cooling (28°C).
The industrial sector has an important role in achieving ambitious targets for CO2 emission reduction set by many countries. Reducing CO2 emissions in the industrial sector requires decreasing energy demand and increasing renewable energy use. In order to utilize variable renewable energy directly in a manufacturing plant, energy conversion and storage facilities are needed to balance supply and demand. Especially in plants with seasonally fluctuating demand, mass storage of energy will be required.
In this paper, we applied the structural optimization using linear programming to plants with zero CO2 emission through the use of variable renewable energy, and clarified the configuration of economically rational renewable energy, conversion and storage equipment. In the plants that needs to supply power and gas (hydrogen and/or methane) to the production lines, a stand-alone case and a case where hydrogen and methane could be supplied from external sources were examined. As a result of structural optimization, power to gas was selected in both cases. Analysis of shadow price in the gas demand constraint revealed that there ware periods when the cost of producing gas through Power to Gas was less than the cost of purchasing gas from external sources.
The purpose of this study is to analyze the cost reduction possibility in Power-to-Gas with solar photovoltaic based on price estimations of renewable electricity in near future. The results show that (1) Levelized cost of hydrogen (LCOH) with solar photovoltaic is about 51.9 Yen/Nm3 in Japan in 2030; (2) It is possible to reduce the cost up to 46.3 Yen/Nm3 by optimizing the capacity of electrolysis and (3) The cost of Power-to-Gas hydrogen produced in Australia would be about the same as that in Japan due to the high cost of transportation in the form of liquified hydrogen. Actual output data of solar photovoltaic generation at Yokosuka area was applied to obtain the relationship between LCOH and the load factor of electrolysis. When the installed capacity of the water or steam electrolysis is reduced, the cost of electrolysis is reduced. However, the cost of electricity is increased due to the curtailed output. It is shown in the present study that LCOH achieves the minimum value when the relative capacity of electrolysis to solar photovoltaic is 0.65.
This study is undertaken to analyze the photovoltaic generation potential of agricultural areas in the National Capital Region of Japan. This work demonstrates a method for assessing the photovoltaic generation potential of abandoned farmland using grid square statistics on higher-resolution. The technique enables researchers to incorporate topographic conditions. This paper comprises three simulation cases: Case 1 (abundance), Case 2 (introduction potential), and Case 3 (possible introduction). It investigated the use of overlay analysis to find south-facing slopes with a maximum inclination angle of less than 20 degrees. The photovoltaic generation potential amount was estimated by exclusion of natural park areas and natural conservation areas. Furthermore, grid square statistics were extracted using sensitivity analysis of the distances from transmission lines to the abandoned farmlands. The author presented estimates with three simulations annual yielding production potential of 39,234 GWh, 14,676 GWh, and 5,679 GWh, respectively. The annual possible introduction was found to be equivalent to 1.9% of the electric power consumption in these areas in the fiscal year 2015. The possible introduction surpassed the annual electric power consumption of the agriculture sector by a factor of 10.2.