Kansai Electric Power Company Research Articles

Concurrent 22. Presentation for: Central Queensland hydrogen project

Presented on Thursday 19 May: Session 22 Renewable hydrogen is being heavily promoted around the world for energy storage, and to support the decarbonisation of energy systems. Queensland is well placed for hydrogen export to Asia and is actively working to make this a reality. Stanwell Corporation, together with its project partners Iwatani, APA Group, Kawasaki Heavy Industries, Marubeni and Kansai Electric Power Company, is working to develop a commercial world-scale project to produce and export hydrogen from Gladstone to Japan, supporting Japan’s Net Zero by 2050 commitment. The size of the hydrogen production system (3 GW) is significant and as a first of a kind in Queensland raises several technical, regulatory and social challenges. To highlight the scale of the project, the renewable power generation to be installed to support this project will have a capacity equivalent to the current Queensland daily power demand. There are several challenges, one being that solar and wind energy resources by their nature are variable. Identifying and defining the mix of renewable energy to achieve a reliable power supply, and integrating this with the electrolyser systems, will be key to the success of the project. The upgrades required to existing power transmission infrastructure are significant, while additional water supply in the Gladstone region will be required. Finally, recent developments in Gladstone have created a boom–bust cycle and the social acceptance of this development requires ongoing engagement to address community concerns. To access the presentation click the link on the right. To read the full paper click here

Central Queensland hydrogen project

Renewable hydrogen is being heavily promoted around the world for energy storage, and to support the decarbonisation of energy systems. Queensland is well placed for hydrogen export to Asia and is actively working to make this a reality. Stanwell Corporation, together with its project partners Iwatani, APA Group, Kawasaki Heavy Industries, Marubeni and Kansai Electric Power Company, is working to develop a commercial world-scale project to produce and export hydrogen from Gladstone to Japan, supporting Japan’s Net Zero by 2050 commitment. The size of the hydrogen production system (3 GW) is significant and as a first of a kind in Queensland raises several technical, regulatory and social challenges. To highlight the scale of the project, the renewable power generation to be installed to support this project will have a capacity equivalent to the current Queensland daily power demand. There are several challenges, one being that solar and wind energy resources by their nature are variable. Identifying and defining the mix of renewable energy to achieve a reliable power supply, and integrating this with the electrolyser systems, will be key to the success of the project. The upgrades required to existing power transmission infrastructure are significant, while additional water supply in the Gladstone region will be required. Finally, recent developments in Gladstone have created a boom–bust cycle and the social acceptance of this development requires ongoing engagement to address community concerns.

Developments of SiC devices and SiC inverters aimed at electric power applications

AbstractThe developments of SiC power devices has been proceeded remarkably since 1990. SiC power devices have been payed attentions as one of the candidate power devices for next HVDC transmissions and its R&Ds have been started in the KANSAI electric power company since 1995. In this paper, a series of R&Ds for the SiC devices and SiC inverters performed in the company are presented from the historical viewpoints.

“Mountain dream” or the “submergence of fine scenery”? Japanese contestations over the Kurobe Number Four Dam, 1920–1970

This article explores the often-contentious discussions surrounding the construction of Japan’s largest concrete arch dam, the Kurobe Number Four (Kuroyon), during the middle twentieth century. It investigates this history at varying spatial scales, especially the local and national, to show how synergies among supporters and opponents at these scales could crucially affect the pace and scope of damming along the Kurobe River in the Central Japan Alps. Prior to World War II, local and national-level opponents employed a modern language of scenic preservation and succeeded in forcing dam builders to scale down and relocate their projects away from key scenic spots in the Kurobe River Gorge. After the war, however, dam opponents were unsuccessful in halting the Kansai Electric Power Company (KEPCO) as it set out to construct the 186-meter Number Four Dam in the heart of Chūbu Sangaku National Park. National-level officials, politicians, big businesses, regional boosters, and local tourism promoters all pressed for rapid economic growth and electrification through the “comprehensive development” of Japan’s river valleys after 1945. Within such a policy environment geared toward national reconstruction and “modernization,” KEPCO divided and appeased local and national-level opponents, in large part by pledging to contribute to the development of alpine tourism. An epilogue details the construction of the Number Four Dam, how the Japanese mass media covered the event, and the ultimate impacts of the project as it tamed the once-rapid flows of the Kurobe River.

Can a low-carbon-energy transition be sustained in post-Fukushima Japan? Assessing the varying impacts of exogenous shocks

In the aftermath of the Fukushima nuclear crisis, Japan began contemplating energy policy reforms that drew inspiration from low-carbon research. This article focuses on a question central to advancing low-carbon research in Japan and elsewhere: namely, how does an exogenous shock affect the onset, magnitude, and permanence of changes in electricity consumption? The article employs intervention analysis with an autoregressive moving average (ARMA) model to answer this question. The data analysis reveals that post-Fukushima electricity use underwent a sudden, significant, and sustained reduction across Japan. The shock not only affected the Tokyo Electric Power Company (TEPCO) coverage area but the more distant Kansai Electric Power Company (KEPCO) coverage area. Large electricity users responded with an immediate and significant reduction in electricity consumption that rebounded to below pre-crisis levels; households responded more gradually with no rebound. Two of the more interesting results from the data analysis – the persistence in reductions in the more distant KEPCO coverage area and the rebound among large users – are then explained with a review of survey data and policy trends. Overall the quantitative and qualitative evidence suggests that an exogenous shock may give rise to a reduction in electricity consumption but cannot sustain a low-carbon transition.

Voluntary electricity conservation of households after the Great East Japan Earthquake: A stated preference analysis

This paper examines the voluntary electricity-saving awareness of households after the Great East Japan Earthquake and the subsequent accident at the Fukushima nuclear power station. We conduct a conjoint analysis of consumer stated preferences for the settings of air conditioners, refrigerators, and the standby power of electrical appliances, based on a web questionnaire survey administered in the areas supplied by the Tokyo Electric Power Company (TEPCO) and Kansai Electric Power Company (KEPCO). The main findings of this paper are as follows. First, we observe awareness of voluntary electricity conservation among the households in both the TEPCO and KEPCO areas after the disasters. Second, awareness of voluntary power saving is higher in the TEPCO area, which has been directly affected by the electric power shortages, in comparison with the KEPCO area, where there was no such direct impact. Third, if power prices are to be further raised, the consumer responses to the price changes would be small in both areas. Furthermore, we show that the potential voluntary reduction in electric power consumption of a household in the TEPCO area is 26% more than that in the KEPCO area during the summer peak periods.

E221 関西電力の安全対策強化の取り組み(OS8 軽水路・新型炉・原子力安全(6))

The Kansai Electric Power Company has been carrying out continuously activity for the improvement in safety of nuclear power plants after the TEPCO Fukushima Danchi NPP accident. We thought that the main causes of having resulted in the severe accident were based on the long time SBO and the LUHS accompanying flood, and installed the alternate mobile power source and the alternative injection pumps while implementing the measure against waterproofing as the first safety measures. Now, we are also implementing continuously the further measure against reliability improvement based on the new regulatory safety-standards, and also introduce them.

Microstructural Change of Ni–GDC Cermet Anode in the Electrolyte‐supported Disk‐type SOFC upon Daily Start‐up and Shout‐down Operations

AbstractThe daily start‐up and shut‐down operations were carried out for the 1 kW‐class solid oxide fuel cell stack composed of 46 electrolyte‐supported disk‐type planar cells made by Mitsubishi Materials Corporation and Kansai Electric Power Company. The representative Ni–gadolinia doped ceria cermet anodes in the deteriorated cells were analyzed by the dual‐beam focused ion beam‐scanning electron microscope. The anode microstructures were reconstructed and the microstructural parameters such as triple phase boundary (TPB) length were quantified. The surface area of nickel phase decreased with an increase in the deterioration rate, leading to a reduction in the TPB length. Furthermore, the TPB length had a strong correlation with the voltage deterioration rate.

Relationship between Lightning Discharges and Rapid Changes in Cross Polarization Discrimination of the Ka-band Satellite Radio Signal

Rapid changes in cross-polarization discrimination (XPD) of the satellite radio wave signal (19.45GHz) are observed at 1sec interval in the thunderstorm events. About one third of the rapid changes are found to coincide with the cloud-to-ground lightning strokes which occurred on the south side of our earth station at the distance up to 20km. The distribution of the lightning location indicates that the center of thunder clouds primarily exists to the westward of the radio wave propagation path. At the moment of the rapid changes, more than half the observed data indicate the decrease in XPD. Also, more than two thirds of them show the changing direction of cross-polar phases toward i90deg, which means the decrease in canting angles of ice crystals possibly causing the depolarization changes. These features seem to be enhanced in the middle stage of each lightning event The decrease in XPD may be related to cancellation efiects of depolarization due to the difierence in canting angles between the ice crystals near the lightning and those in other places far from the lightning. Thus, the measurements of XPD and cross-polar phase are shown to be important to reveal the electriflcation process of thunder clouds and to predict lightning discharges. In satellite communication links, degradation of cross-polarization discrimination (XPD) of the radio wave is caused by raindrops and ice crystals along the propagation paths. In thunderstorm events, moreover, rapid changes of XPD and cross-polar phase relative to co-polar phase are fre- quently observed at time intervals of less than 1sec (1,2). These peculiar phenomena are considered to be related to the change of electric fleld due to lightning discharges as well as the aerodynamic forces of convective air ∞ows (3). Up to now, however, detailed mechanisms of the rapid changes of XPD and cross-polar phase are not understood very well. In this study, statistical distributions of the changes of XPD and cross-polar phase are examined using the Ka-band beacon signal observations of Japan's domestic communication satellites (4) which have been conducted for the past 17 years at 1sec (partly 0.1sec) interval in Osaka Electro- Communication University. The thunderstorm events are observed more than 70 times from 1990 to 2006, and more than 2500 examples of rapid XPD changes are obtained during these years in our university. The occurrence time and the amplitude of these changes are then compared with the lightning location and time provided by the Kansai Electric Power Company in Osaka area. Also, the decrease and increase in XPD and cross-polar phase are discussed in relation to the alignment of ice crystals due to electrostatic force and convective air ∞ow in thunder clouds.

Development of IT-SOFC Based on Lanthanum Gallate Electrolyte

The Kansai Electric Power Company, Inc. and Mitsubishi Materials Corporation started a joint research project for developing intermediate temperature (600{degree sign}C to 800{degree sign}C) solid oxide fuel cells (IT-SOFC) in 2001. High performance disk-type cells with lanthanum gallate-based electrolyte and a seal-less cell-stack design enable high efficiency operation at temperatures below 800{degree sign}C. The development of 10 kW-class CHP system under a project supported by NEDO (New Energy and Industrial Technology Development Organization) was started in FY2004. In 2007, the performance test of the 10 kW-class system using town gas as fuel has been undertaken. In this test, the electrical efficiency of 41%HHV on AC power output of 10 kW and the overall efficiency of 82%HHV by recovering 60åC hot water have been achieved. And the voltage degradation rate per 1,000 hours was 1.08% after 3,000 hours operation has been observed during the field test of the 10 kW-class system. Furthermore, after making some refinements to enhance the performance of 10 kW-class module, the second long-term stability test for 3,000 hours were carried out in 2008. Efforts to enhance cell and module durability have been made with 1 kW-class modules operated for 5,000 hours, and with the cell-stack units operated for 15,000 hours. The voltage degradation rates per 1,000 hours were 0.51 % for the 1 kW-class modules, and 0.23 - 0.48% for the cell-stack units.

Development of electrical efficiency measurement techniques for 10 kW-class SOFC system: Part I. Measurement of electrical efficiency

Measurement techniques to estimate electrical efficiency of 10 kW-class SOFC systems fueled by town-gas were developed and demonstrated for a system developed by Kansai Electric Power Company and Mitsubishi Materials Corporation under a NEDO project. Higher heating value of the fuel was evaluated with a transportable gas sampling unit and conventional gas chromatography in AIST laboratory with thermal-conductivity and flame-ionization detectors, leading to mean value 44.69 MJ m −3 on a volumetric base for ideal-gas at the standard state (0 °C, 101.325 kPa). Mass-flow-rate of the fuel was estimated as 33.04 slm with a mass-flow meter for CH 4, which was calibrated to correct CH 4 flow-rate and effect of sensitivity change and to obtain conversion factor from CH 4 to town-gas. Without calibration, systematic effect would occur by 8% in flow-rate measurement in the case for CH 4. Power output was measured with a precision power analyzer, a virtual three phase starpoint adapter, and tri-axial shunts. Power of fundamental wave (60 Hz) was estimated as 10.14 kW, considering from total active power, total higher harmonic distortion factor, and power consumption at the starpoint adapter. The electrical efficiency was presumed to be 41.2% (HHV), though this mean value will be complete only when uncertainty estimation is accompanied.

Analyzing Small Signal Stability of Power System based on Online Data by Use of SMES

The purpose of this study is to estimate eigen-values and eigen-vectors of a power system from on-line data to evaluate the power system stability. Power system responses due to the small power modulation of known pattern from SMES (Superconducting Magnetic Energy Storage) were analyzed, and the transfer functions between the power modulation and power oscillations of generators were obtained. Eigen-values and eigen-vectors were estimated from the transfer functions.Experiments were carried out by use of a model SMES and Advanced Power System Analyzer (APSA), which is an analogue type power system simulator of Kansai Electric Power Company Inc., Japan. Changes in system condition were observed by the estimated eigen-values and eigen-vectors. Result agreed well with the resent report and digital simulation. This method gives a new application for SMES, which will be installed for improving electric power quality.

Analysis of Data on Pipe Wall Thinning Phenomena by Fluid Flow in Pressurized Water Reactor Plant

In August 2004, a pipe rupture accident occurred at The Kansai Electric Power Company Mihama Unit 3. Japan Society of Mechanical Engineers (JSME) recognized that it was an urgent problem to settle the rules on pipe wall thinning management by fluid flow. JSME enacted rules on pipe wall thinning that stipulates the basic requirements of pipe wall thinning management, considering from these situations, and in 2006, the “Rules on Pipe Wall Thinning Management for PWR Power Plants” (JSME S NG 1-2006, JSME rules for PWR) that satisfies the requirements of rules on pipe wall thinning. This JSME rules for PWR stipulates the process of inspection plan, measurement, evaluation and maintenance. This paper focuses on the technical grounds that specify the management systems, pipe components and initial FAC rate.

Comparative Evaluation of Reliability by Monte Carlo Method among different Loop Distribution Systems

The situation in which the plan of a new distribution network system should be examined as an electric power company approaches by the multi-machine interconnection of the distributed generators that will be expected in the near future. Then, the authors assumed applying the distribution system which may be adopted as the near future to a system and equipment of the Kansai Electric Power Company, and executed the reliability evaluation concerning the outage energy and voltage sag power that used the real scale model of distribution system by the stochastic reliability evaluation that used the Monte Carlo method.

Development of Intermediate Temperature Solid Oxide Fuel Cell Modules and Systems

The Kansai Electric Power Company, Inc. and Mitsubishi Materials Corporation started a joint research project for developing intermediate temperature solid oxide fuel cells in 2001. High performance disk-type cells with lanthanum gallate- based electrolyte and a seal-less cell-stack design enable high efficiency operation at temperatures below 800{degree sign}C. The 4th generation 1 kW-class module with internal manifolds was developed and the electrical efficiency of 54%HHV-DC was achieved in 2005. In the first durability test of the 4th generation 1 kW-class module carried out for 4,200 hours in 2006, the voltage degradation rate was about 0.5%/1,000hours. In parallel, the development of 10 kW-class module and CHP system has been in progress since 2004. 10 kW-class module test was carried out and the efficiency of 50%HHV at electric power output of 12.6 kW-DC was achieved in 2006. The field test of 10kW-class CHP system will be carried out in FY2007.

A Very Short-Term Load Forecasting Method for Economic Load Dispatching Control

This paper proposes a very short-term load forecasting technique in order to make Economic Load Dispatching Control (EDC) more effective. The controllable periodic term of EDC is made clear through power spectrum analysis of actual load and actual EDC outputs of the Kansai Electric Power Company. A real-time predictor is designed based on this result, and it can decrease the EDC error at almost the same level as the actual AR (Area Requirement: final error after EDC and LFC) through the year. In addition, it can be seen from the generation simulation by using this predictor that we can decrease the fuel cost and LFC margin.

Test results of a 30 m high-tc superconducting power cable

Furukawa Electric is developing technologies for reducing the AC losses in and cooling HTS cables as part of the Super-ACE project. These technologies are important to facilitate the introduction of HTS cable into the electric power network. Furukawa executes research on these topics under the support of Chubu Electric Power Company, Tokyo Electric Power Company and Kansai Electric Power Company. We report on the progress of technology development for cooling long scale superconducting cables. The HTS cable is designed as a single core, 77 kV cable with cryogenic dielectric. A 30 m long cable was manufactured and tested to obtain design data for the 500 m long cable that will be tested in CRIEPI in 2004. The cable manufactured here used transposition tape twisted by six tapes of Bi2223. In the 30 m-cable tests, the influence of thermal contraction on critical current and heat invasion was examined. The tests confirmed that our cable can withstand thermal contraction. Moreover, useful data for cable design such as pressure drop and thermal contraction stress were obtained. We started manufacturing and preparing for substantive tests of 500 m-cable based on the success of these tests.

Dependence of dc output of a rectenna array on the method of interconnection of its array elements

In 1994 and 1995, a ground-to-ground microwave power transmission (MPT) experiment was carried out by a group including participants from Kyoto University, Kobe University, and Kansai Electric Power Company. Among the MPT technologies, which are one of the most important key issues for the realization of the Solar Power Satellite, the “rectenna” (rectifying antenna) has been studied to achieve higher efficiency of conversion from microwave to dc We had developed a new rectenna panel which can effectively rectify a microwave power of 2.5 W at 2.45 GHz, prior to the ground-to-ground MPT field experiment. We examine the sum of the outputs of two or three rectenna panels which are connected either in parallel or in series or in a hybrid manner under the same microwave circumstances. The experiments lead us to conclude: (1) The sum of the dc outputs from two rectenna panels connected in parallel is larger than that from those connected in series. (2) The sum of the dc outputs of two rectenna panels is generally smaller than the sum of the dc output of the individual panels unless their outputs are equal. (3) Better total output dc power of a rectenna array is achieved when we take careful account of the array element balance. Based on the experiments, we propose an optimum method for connection of individual rectenna elements to form a high-efficiency rectenna array. © 1998 Scripta Technica, Electr Eng Jpn, 125(1): 9–17, 1998

Modeling air conditioner load for power system studies

The air conditioner load is the most variable component of the system load of the Kansai Electric Power Company. As the air conditioner load changes with temperature and time, the voltage and frequency characteristics of the system load change as well as its magnitude. Single-phase air conditioner characteristics have been determined through measurement, and simple models suitable for power system studies have been developed.

Experimental study of large rectenna array for microwave energy transmission

For a field experiment on microwave power transmission (MPT) which was jointly conducted by the Radio Atmospheric Science Center of Kyoto University, Robe University, and Kansai Electric Power Company from 1994 to 1995, we had developed and tested a new type of rectenna (rectifying antenna) based on a circular microstrip antenna (CMA). A square shape of array with an area of 3.2 m/spl times/3.6 m was then constructed using the developed rectennas for experiment. The whole rectenna array is composed of 256 sub-arrays, each with nine rectenna elements. We place the rectenna sub-array with better RF-DC conversion efficiency in the central area of the whole rectenna array. Such spatial optimization is needed because the power density of the microwave beam used in the experiment has a spatial gradient with a peak at the center of the beam. We then examined dependence of the rectenna array characteristics on the electrical connection of the sub-arrays. The difference of the output DC power of the whole array for five different electrical connections is within 5%. The load characteristics, therefore, suffers little change even if the electrical connection of the rectenna sub-array is changed.