Annual Electric Power Consumption Research Articles

Permanent VS Transitory Shocks to Electricity Consumption: Panel Evidence from 19 African Countries

ABSTRACT: Considering Africa's increasing electricity demands and the pivotal role of electricity in socio-economic development, this study addresses a research gap in understanding the stochastic properties of per capita electricity consumption in African contexts. Through examining the integration properties of per capita electricity consumption across 19 African countries, the research determines whether 'shocks' yield transitory or permanent effects, aiding policy formulation and future demand forecasting. Annual electric power consumption data (1971 – 2014) (kWh per capita) from the WDI across 19 African countries are used. Our methodology starts with formally testing for cross-sectional dependence (CSD) using various tests to avoid potential size distortions. Subsequently, we employ the novel panel stationarity test of Nazlioglu and Karul (2017), a Fourier KPSS panel stationarity test. The robustness of the analysis is enriched by incorporating the Hadri and Kurozumi (2011) panel stationarity test and Nazlioglu et al. (2021) new panel stationary tests. The CSD test results reveal mutual dependency in electricity consumption among the sampled African countries, underscoring the need for a panel testing methodology that accommodates CSD. The results of the panel stationarity tests that allow CSD and structural breaks—specifically, the Nazlioglu and Karul (2017) test, which models structural breaks as a gradual process—reject the null hypothesis of trend stationarity for both single frequencies, i.e., k =1, and 2. Similarly, all new, complementary panel stationarity tests from Nazlioglu et al. (2021) reject the null hypothesis of stationarity for both frequencies. Collectively, the outcomes from various panel stationarity tests present strong evidence of nonstationary per capita electricity consumption within the sampled African countries. Additionally, the Nazlioglu and Karul panel stationarity test enables an analysis of the individual Fourier KPSS test for cross-sectional units in the panel. Of the 19 countries, only Togo does not reject the null hypothesis of stationarity for both frequencies. These individual country results align with the panel outcomes, providing compelling evidence for the nonstationarity of the per capita electricity consumption series across the investigated African nations. Accordingly, shocks to electricity consumption will have permanent effects, indicating that per capita electricity consumption will not return to its pre-shock equilibrium path. In this case, demand or consumption stabilizing policies will have long-run effects.

Change in Electric Power Consumption in Mongolia in 2020 and the Impact of the COVID-19 Pandemic

This paper deals with the change in electric power (EP) consumption in Mongolia in 2020 based on data on the maximum and minimum EP consumption a day, provided by NPTG. The changes in EP consumption in Mongolia in detail as weekly or seasonal changes as well as the impact of the COVID-19 pandemic have not been clear, even though annual EP consumption was provided from the reports of the World Bank, IEA, and other international institutes as statistical data. Differences in the maximum average hourly and the minimum EP consumption in a day was 277 MWh (30.2%) and in the maximum and minimum daily EP consumption in 2020, which appeared in winter and summer, respectively, was 933 MWh (71.3%). Also, a 104-MWh (14.8%) drop was confirmed on special days like Naadam. To discuss the impact of COVID-19, the values of 2017 were used as a criterion for a year absent of a pandemic, and the stringency index, an indicator used to quantify the severity and stringency of government policies and measures, was introduced, and compared with the monthly EP consumption in 2020. The COVID-19 pandemic decreased the EP consumption of 40 MWh (2 to 6%) except in December due to the free-electricity policy. The EP consumption showed the dependency of the stringency index, particularly a clear drop over 50 of the index values. These new findings of EP consumption properties are expected to apply EP demand forecasting and make design plans for future EP systems in Mongolia.

Forecasting annual electric power consumption using a random parameters model with heterogeneity in means and variances

This paper develops heterogeneity-based econometric models that forecast the yearly consumption of electricity. Unlike previous research, this paper departs from classical econometric regression models and explicitly accounts for unobserved heterogeneity and corresponding interactions. More specifically, three modeling approaches are applied: a random parameter linear regression model (RPLRM), a correlated random parameter linear model (C-RPLRM), and a random parameter linear model with heterogeneity in means and variances (RP-HMV). In addition, a grey model is estimated based on historical consumption data. The estimation results clearly demonstrate that the random parameter methodology is statistically superior to the classical multiple linear regression model. Moreover, based on the test results reported in this paper, as well as the forecasting accuracy measures, the RP-HMV model is shown to be statistically outstanding, with a very low forecasting error (MAPE of 0.04%) compared to the other models, including the grey model. Our estimation results show that two variables, namely the average electricity price and contribution of renewable energy to the national and distribution grids, produced statistically significant random parameters with heterogeneous variances and means. Moreover, the results show that factors including the number of households on the distribution grid, average electric power price, and availability of all-season air conditioners with hot and cold inverter characteristics significantly influenced the electricity consumption. These empirical results reveal that random-parameters models with heterogeneity in their means and variances can provide a detailed analysis of the predictor variables shaping the annual electricity consumption, and they highlight the importance of including unobserved heterogeneity and related interactions in econometric models.

Estimating electrification using multi-temporal DMSP/OLS night imagery as proxy measure of human well-being in India

Annual electric power consumption (EPC) measures the electrification rate of a region. In the present study, annual composites of temporal defense meteorological satellite program/operational line-scan system night time light (NTL) imagery is used as a proxy measure for estimating electrification of India. A regression model is obtained using temporal NTL and EPC data of the region for measuring EPC from NTL data. The model is validated by using NTL data of India aquired during 2013 and is observed to be 99% accurate in measuring EPC from NTL data. The NTL data is also used to estimate population of the region and are found to be positively correlated with each other. The present study supports using the NTL data as a proxy measure of human wellbeing.

Asymmetrical Modes of Outdoor Lighting Lines

Asymmetrical modes of the outdoor lighting network can be caused by disconnecting of a part of the luminaires in order to electrical energy savings at night; also – by asymmetry of voltage in power points. The possible alternative symmetric modes of energy saving to replace the incomplete-phase operation of the line have been analyzed. Calculations of various symmetric and asymmetric modes of the lighting line were carried out without taking into account and taking into account high harmonics up to the 39th one. Calculations have been performed with the programs of MathCad software. As light sources, in the calculations the widely used luminaries with high-pressure sodium arc lamps connected through electromagnetic start-up equipment were considered. Such luminaries are sources of high harmonics, and they distort the sinusoidal voltage. The values of currents, power, power loss, voltage drop in all areas of the lighting line, the voltage at the terminals of the lamps for each phase (operating parameters) are determined. The diagrams of the voltage distribution at the points of the lighting line are plotted for the considered modes of operation. The annual electric power consumption of the lighting line has been calculated for different variants of operation, and the obtained results have been compared. When refusing to disconnection of part of the luminaires at night and using a smooth transition to a lower voltage (symmetrical) at a power point or using two-stage ballast devices, uneven illumination appears less when the level of electricity consumption is comparable. The presence of voltage asymmetry at the power point, as well as the disconnection of one phase, leads to an increase in currents, power losses and voltage. The current in the zero working conductor can exceed the currents in the phase conductors (when calculated taking into account the higher harmonics). Accounting for higher harmonics allows one to determine the operating parameters more accurately, on the basis of which the electricity power consumption can be estimated.

A novel PSO (Particle Swarm Optimization)-based approach for optimal schedule of refrigerators using experimental models

Refrigerators have considerable share of residential consumption. They can be, however, flexible loads because their operating time and consumption patterns can be changed to some extent. Accordingly, they can be selected as a target for the study of Demand Side Management plans. In this paper, two experimental models for a refrigerator are derived. In obtaining the first model, following assumptions are made: the ambient temperature of refrigerator is assumed to be constant and the refrigerator door is remained closed. However, in the second model the variation of ambient temperature and door-opening effects are considered according to some general patterns. Further, two strategies are proposed to reduce the annual electricity cost and electric power consumption at peak-load times. These strategies together with the aforementioned models form an optimization problem which is, then, solved by Particle Swarm Optimization algorithm. Simulation results indicate a reduction of more than 28.61% in the annual cost. Also, the annual electricity consumption has decreased more than 20.46% and load shifting from the peak periods has achieved about 40%. In addition, these approaches are implemented in laboratory and their performance is confirmed by experimental results.

중앙식 냉방 플랜트의 유량제어를 통한 에너지 절감에 관한 연구

In a centralized cooling plant, precise mechanical design and control strategy are required for peak and partial cooling load management. Otherwise, it will lead to low efficiency of cooling system and energy loss due to low partial load efficiency. The purpose of this paper is to enhance energy performance of the centralized cooling plant by controlling flow system in an industrial building using measured data and energy performance simulation program. The simulation results show that the proposed flow control can cut down annual electric power consumption by about 17% compared with the conventional cooling system.

Performance characteristics of a combined air conditioner and refrigerator system interconnected via an intercooler

Convenience stores and supermarkets are equipped with air conditioner and refrigeration/freezer systems that are independently operated; these systems consume approximately 50%–60% of the total electric power used by the convenience store or supermarket. In this study, a combined system that can recover the condensation heat of the refrigeration system into the air conditioner using an intercooler is developed. Experimental investigations are conducted in order to investigate the performance characteristics of the combined system. Then, the proposed combined system is installed in a convenience store and operated for one year in order to measure the annual power consumption in a real environment. The proposed combined system exhibits an increase in the operation ratio, a reduction in defrosting operations, and a 32% reduction in the annual electric power consumption. The intercooler contributes to the reduction in power consumption, as does the use of a variable speed compressor. It is also found that the flow rate of the intercooler should be optimized when the air conditioning system is operated in the cooling mode.

Sizing a solar dish Stirling micro-CHP system for residential application in diverse climatic conditions based on 3E analysis

A solar dish Stirling cogeneration system is considered to provide energy demands of a residential building. As energy demands of the building and output power of the engine are functions of weather condition and solar irradiation flux, the benchmark building was considered to be located in five different cities in Iran with diverse climatic and solar irradiation conditions. The proposed solar dish Stirling micro-CHP system was analyzed based on 3E analysis. The 3E analysis evaluated primary energy saving analysis (energy analysis), carbon dioxide emission reduction (environmental analysis) and payback period for return of investment (economic analysis) and was compared to a reference building that utilized primary energy carriers for its demands. Three scenarios were considered for assessment and sizing the solar dish Stirling engine. In the first scenario, size of the solar dish Stirling engine was selected based on the lowest annual electric power demand while, in second, the highest annual electric power consumption was considered to specify size of the engine. In the third scenario, a solar dish Stirling engine with constant output capacity was considered for the five locations. It was shown that implementing the solar dish Stirling micro-CHP system had good potential in primary energy saving and carbon dioxide emission reduction in all scenarios and acceptable payback period for return of the investment in some scenarios. Finally, the best scenario for selecting size of the engine in each city was introduced using the TOPSIS decision making method. It was demonstrated that, for dry weather, the first scenario was the best while, for hot and humid cities and temperate and humid places, the second and third scenarios were the best options, respectively.

반도체 클린룸용 증기가습 및 수분무가습 외기공조시스템의 에너지소비량 평가

For a large-scale semiconductor manufacturing clean room, the energy consumed in an outdoor air conditioning system to heat, humidify, cool and dehumidify incoming outdoor air is very large. In particular, the energy requirement to humidify outdoor air in the winter season is generally known to be high. Recently, in order to overcome the high energy consumption nature of a steam generator in a conventional steam humidification type outdoor air conditioning system, an air washer is often introduced instead of the steam generator in the outdoor air conditioning system, which can be called a water spray humidification type outdoor air conditioning system. Therefore, the assessment and comparison of the annual energy consumed in the steam humidification type and the water spray humidification type outdoor air conditioning systems deserves to be examined in order to reduce the outdoor air conditioning load of a clean room. In the present study, a numerical analysis was conducted to obtain the annual electric power consumption of the two outdoor air conditioning systems. It was shown from the comparison of the numerical results that the water spray humidification type outdoor air conditioning system can reduce about 30% of annual electric power consumption of the steam humidification type outdoor air conditioning system.

반도체 클린룸용 증기가습 및 수분무가습 외기공조시스템의 에너지소비량 비교연구

ABSTRACT:For a large-scale semiconductor manufacturing clean room, the energy consumed in an outdoor air conditioning system to heat, humidify, cool and dehumidify incoming outdoor air is very large. In particular, the energy requirement to humidify outdoor air in the winter season is generally known to be high. Recently, in order to overcome the high energy consumption nature of a steam generator in a conventional steam humidification type outdoor air conditioning system, an air washer is often introduced instead of the steam generator in the outdoor air conditioning system, which can be called a water spray humidification type outdoor air conditioning system. Therefore, the assessment and comparison of the annual energy consumed in the steam humidifica-tion type and the water spray humidification type outdoor air conditioning systems deserves to be examined in order to reduce the outdoor air conditioning load of a clean room. In the present study, a numerical analysis was conducted to obtain the annual electric power consumption of the two outdoor air conditioning systems. It was shown from the comparison of the numerical results that the water spray humidification type outdoor air conditioning system can reduce about 30% of annual electric power consumption of the steam humidification type outdoor air conditioning system.Keywords:Clean room(클린룸), Outdoor air conditioning system(외기공조시스템), Annual energy consumption(연간 에너지 소비량), Steam humidification(증기가습), Water spray humidification(수분무가습)

A STUDY ON ELECTRIC POWER CONSUMPTION OF COMMON SPACE IN MULTIPLE DWELLING HOUSES

In this study, the amount of electric power consumption of the common space in middle and high-rise multiple dwelling houses in the Tokai region are investigated and the actual condition of them are clarified. The major results in this study are as follows. 1) The annual average of electric power consumption of common space in condominiums is 3.19 (GJ/year) per one dwelling unit, and this value is equivalent to about 10% of the annual amount of energy consumption per one multiple dwelling unit. 2) Because there is a high correlation between the annual electric power consumption of common space and the architecture gross floor area, the annual electric power consumption of common space can be presumed only with the architecture gross floor area.

Characterization of energy use in 300 mm DRAM (Dynamic Random Access Memory) wafer fabrication plants (fabs) in Taiwan

Abstract Driven by technology advances and demand for enhanced productivity, migration of wafer fabrication for DRAM (Dynamic Random Access Memory) toward increased wafer size has become the fast-growing trend in semiconductor industry. Taiwan accounts for about 18% of the total DRAM wafer production in the world. The energy use required for operating wafer fabrication plants (fabs) is intensive and has become one of the major concerns to production power reliability in the island. This paper characterizes the energy use in four 300 mm DRAM wafer fabs in Taiwan through performing surveys and on-site measurements. Specifically, the objectives of this study are to characterize the electric energy consumption and production of 300 mm DRAM fabs by using various performance metrics, including PEI ((production efficiency index), annual electric power consumption normalized by annual produced wafer area) and EUI ((electrical utilization index), annual electric power consumption normalized by UOP (units of production), which is defined as the product of annual produced wafer area and the average number of mask layers of a wafer). The results show that the PEI and EUI values are 0.743 kWh/cm 2 and 0.0272 kWh/UOP, respectively. Using EUI in assessing energy efficiency of the fab production provides more consistent comparisons than using PEI alone.

A study on the energy performance of a cooling plant system: Air-conditioning in a semiconductor factory

This paper will focus on the energy performance evaluation of a cooling plant system in a semiconductor factory. Several energy saving technologies namely: integrated cooling towers, free cooling systems, control of the chilled water quantity, etc., have been adopted to improve efficiency of the cooling plant system. We have collected actual operating data for 2 years and evaluated the performance of chillers’ COP and the whole cooling plant system's COP and they showed satisfactory results even if the thermal load of the factory was about half compared with design phase assumption. We also have verified each effect of the energy saving technologies through model-based simulation analysis. The annual electric power consumption dropped about 35% compared to conventional cooling plant systems in case of design phase thermal load. And the faulty status operation of the chiller's number control miss occurred while we monitored. Electric power consumption increased about 17% compared to normal status operation at the same period.

Energy performance of a cooling plant system using the inverter chiller for industrial building

The purpose of this paper is to clarify energy performance of the cooling plant system in the industrial building using actual measured operating data and numerical simulation analysis. One aspect of industrial buildings is that they have large energy consumption for manufacturing and air-conditioning compared with office and commercial buildings. Some examples of high-efficiency technologies installed in this particular cooling plant system are inverter chillers, integrated cooling towers and a free-cooling system. The inverter chiller which has been put on the market recently is state-of-the-art technology. The maximum COP of the inverter chiller reaches about 18 under certain conditions and integrated cooling towers make lower temperature cooling water as the whole capacity is large. Actual operating data indicates satisfied values for chiller and system COP during the running period and the simulation results show that the cooling plant system can cut down annual electric power consumption by about 48% compared with conventional cooling system.

昼光照明の簡易エネルギー評価手法の開発

This paper describes a method for estimating the decrease in annual electric power consumption for lighting due to daylighting. The proposed method is to use a chart for calculating annual mean daylight illuminance in a given room space and then to estimate the annual electric power consumption for lighting. The parameters included in the chart are window size, window orientation, room reflectance, and window types. Annual electric power consumptions estimated using the proposed chart were found in good agreement with those calculated by detailed computer simulation.