Toward Stable Supply of Electrical Energy Following the March 11 Earthquake

Transcription

1 Toward Stable Supply of Electrical Energy Following the March 11 Earthquake Shintaro Furusaki Professor Emeritus, The University of Tokyo WFEO-ICESEDC 2013, Guangzhou September 7, 2013

2 From Asahi Shimbun,

3

4 Annual Consumption of Electricity in Japan Total primary energy consumption = 22,000 PJ (22 EJ) decreasing since 2007 Primary energy to produce electricity = 10 EJ (44% of the above) Supply of electricity = 4 EJ (40% efficiency of production) Expected consumption by saving energy = 3.6 EJ (3600 PJ) = 1000 TWh (cf. 1 kwh = 3.6 MJ, 1 TWh/y = 114 MW)

5 Contents 1.Supply and Demand of Electrical Energy in Japan 2.Safety of Nuclear Power Plants in Japan 3.Problems and Possibility of Natural Energy 4.Saving Energy 5.Scenario toward the Energy System in the Low Carbon Society 6.Summary

6 Expectation of Electric Supply Balance (August 2012: %) Area Supply(GW) Case1 Case 2 Case 3 Hokkaido Tohoku Tokyo Central Kansai Hokuriku Chugoku Shikoku Kyushu Average Case 1: Intense heat Case 2: Intense heat with energy saving Case 3: Moderate heat with energy saving In all cases nuclear power plants are not in operation. Data from Federation of Electric Power Companies (FEPC)

7 Expectation of Electric Supply Balance (2013: %) Area Supply(GW) 1 July August September Hokkaido Tohoku Tokyo Central Kansai Hokuriku Chugoku Shikoku Kyushu Average ) Supply values are for the case of July. All data are calculated for the case of intense heat. Data from Federation of Electric Power Companies (FEPC)

8 Safety of Nuclear Power Plants in Japan

9 Safety 1 (in general) 1. Safety is defined as the status where the risks of damage are in the allowable range. 2. Some sort of risks exist at any time. 3. It is required to clarify the possible risks. 4. Risks which will cause destructive damages cannot be allowed even if their occurrence probability is quite low. 1) Toward smooth supply of electricity after the Fukushima Daiichi Nuclear Power Plant Accident, Information, No.150, Eng. Acad. Jpn. (2011, in Japanese)

10 Establishing Safety 1 We have to know the fact that machines and apparatuses always deteriorate. Also, human beings will make some errors someday. [Safety design for high risk systems] fail-safe, fool-proof fault-tolerance multi-layered and independent control passive safety-control (move toward safe-side at any time) 1) Toward smooth supply of electricity after the Fukushima Daiichi Nuclear Power Plant Accident, Information, No.150, Eng. Acad. Jpn. (2011, in Japanese)

11 Safety of Nuclear Power Plant 1 (in general) 1. We have to consider that accidents which were not expected in initial design will occur someday. 2. Probability of accident occurrence cannot be zero. 3. We cannot reach the true safety until we find measures to prevent from big accidents of low probability. 1) Toward smooth supply of electricity after the Fukushima Daiichi Nuclear Power Plant Accident, Information, No.150, Eng. Acad. Jpn. (2011, in Japanese)

12 Problems of Fukushima Daiichi Nuclear Power Plant 1 1. Geographical condition a. Concentrated location Only one substation for electric supply to 4 reactors. Ventilation towers are designed as common use for two reactors. b. Plant height from the sea level was insufficient. Prevention against tsunami wave was inadequate. 1) Toward smooth supply of electricity after the Fukushima Daiichi Nuclear Power Plant Accident, Information, No.150, Eng. Acad. Jpn. (2011, in Japanese)

13 2. Problems in design and operation of the Fukushima nuclear power plant 1 a. Emergency power supply system was located in the basement of the reactor building. b. Prevention against hydrogen explosion was not sufficient. c. Protection against natural disasters was not sufficient. d. Emergency protection and information system did not work adequately. 1) Toward smooth supply of electricity after the Fukushima Daiichi Nuclear Power Plant Accident, Information, No.150, Eng. Acad. Jpn. (2011, in Japanese)

14 Problems in design and operation of the Fukushima nuclear power plant (continued) f. Measures and the standard of operation (SOP) to prevent severe accidents were not revised for a long time since they had been provided. Training and education of operators were not sufficient. g. There were no targets for safety. h. Enthusiastic attitude in managing system to keep good quality of electric supply was not sufficiently related to plant safety.

15 New Safety Standard by Japanese Nuclear Regulatory Commission 1. Measures to prevent severe accidents are newly added. e.g.) prevention of diffusion of radioactive materials, measures against terrorism, measures to prevent damage of fuel core and/or containment vessel, etc. 2. Reinforced items: Consideration to natural disasters and fire Reliability of electric power supply Reactor cooling system 3. Improvement of the quality of earthquake- and tsunami-resistant facilities

16 Cost of nuclear power generation The cost of nuclear electric power generation is discussed by many people. (unit: yen/kwh, 1 yen = ca. 1 US cent) Cheapest evaluation: 5~6 Inst. Energy Eng. Jpn 1 : 7.2 (with back-end cost) K. Oshima 2 : 8.5 (without back-end cost) Oshima claims that the cost will be 10.3 yen/kwh by adding the research/development and location costs. He says that the compensation cost of the accident will be 1.3 yen/kwh. However, if the cost of remediation of radioactive environment is over 5 trillion yen 3 (ca. 50 billion dollars), it will be ca. 174 yen/kwh. Thus, my assumption is about 10 yen/kwh or more Oshima,K.: Cost of Nuclear Power Generation (in Japanese), Iwanami Publ. (2012) 3. Nakanishi. J.: AIST report from NHK News (2013.7)

17 Possibilities of natural (renewable) energies

18 Development of natural (or renewable) energy sources Speed of the development of utilization of natural energy has been very slow in Japan. Annual investment to utilization of natural energy in Japan is about 2000 yen (ca.20us dollars) per person, whereas that of China is about $ 30 per person. Japan s national investment in this technology accounts for only 1~2% of that of the whole world.

19 Photovoltaics (PV, Solar cells) Key issues regarding PV are the efficiency of energy conversion and the cost of components (materials). If the conversion efficiency becomes 20 % (now it is about 15 %) and the equipment cost is below 2 dollars/kwh, the cost generating electricity will be ca. 20 yen/kwh (= 20 cents/kwh). The influence of the weather is significant for PV. It does not work at night. Annual operation hours are only 1000 h in Japan. However, the PV equipments can be installed on the rooftops of buildings or in fallow fields. Therefore, the potential of the use of PV is high.

20 Windmills The cost of generating electricity is lower than PV. The weather strongly affects the efficiency. The necessary installation area on the ground is relatively large. There are not many suitable locations for windmills. Therefore, the oceanic windmill generator seems to be promising.

21 Geothermal Electric Power Generation Japan has the third geothermal potential in the world, although the present capacity of geothermal power generation is the sixth in the world. Negotiation with hot spring business is necessary. Cost depends on the location and the method of boring.

22 Hydroelectric Power Generation (middle or small scale) The generated power of a station of this kind is less than 30 MW and small. Construction of dams is unnecessary and there are a lot of possible locations. Because the scale of the generators is small, the cost of the electricity is generally high. (large scale) Capacity can be increased by raising the existing dam banks, which is promising.

23 Electric power generation using biomass Since the biomass sources are located in dispersed areas, collecting them becomes costly. The geographical range that trucks can collect biomass is said to be within 30 km. Therefore, transportation cost is high. As power plants in this category is in small scale, the cost of electricity becomes high.

24 Thermal power generation Thermal power generation plays salient roles since most of the nuclear power plants have stopped operation. There is the problem of exhausting carbon dioxide. Therefore, the carbon capture and storage (CCS) process is desirable in the future. Recent development of technology in this field is significant, such as Integrated Gasification Combined Cycle (IGCC) and Advanced Ultra Supercritical (A-USC) generation. The generation efficiency will become over 46 % compared with 40 % in case of the normal systems. Shale gas/oil is prospective in the near future. China and USA have its enormous reserves. Although there is environmental concern in mining, shale gas/oil will contribute to reduce the cost of thermal power generation.

25 Costs and Potentials of Various Generation systems Cost (yen/kwh) Potential (GW) Nuclear ca. 10 na Thermal (coal) 6-7 na Thermal (LPG) ca. 10 na Solar cell hopefully 20 na Wind mills (land), 81(ocean) Geothermal same as above 24 (above 150C), 9.6 (53-150C) Hydrogeneration (raising banks), 14 (others) Biomass Sum of potentials of natural energies except PV na = not applicable Annual consumption in Japan: 1000 TWh/y In average, 1000 TWh/y corresponds to 114 GW. Considering the efficiency of generation and the peak demand during the daytime, the capacity should be more than this value. Let s assume that 350 GW of the equipment capacity is needed. Then, natural energy sources excluding PV can cover about 40 % of the demand.

26 Effect of energy saving Energy savings play an important role to reduce electricity consumption. In the spring of 2011 after the Fukushima accident the supply capacity was about 40 GW compared with the original 60 GW in Tokyo Area (in the area covered by Tokyo Electric Power, Inc.) The deficit could be covered by pumped storage hydro-generation, generation by independent power producers (IPP) and energy saving of community and individual citizens. Altogether, ca. 50 GW was secured for electric supply. Some possible saving ways (ca. 5 GW in Tokyo area) are given below: 1. Change of lifestyle, Decrease in using lights and in running elevators, escalators, trains, etc. 2. Shift of working time and working sites (to avoid peak demand)

27 Procedures to achieve stable supply of electrical energy Japan has now surplus electrical energy without nuclear power generation by extensive operation of thermal power generation (Only two nuclear plants are in operation at this moment). It will be desirable if natural, reproducible energies are applied more widely. To promote the natural energies the FIT (Feed-in Tariff) system has been recently introduced in Japan. However, the prices of electricity of the present FIT seem to be quite high. In order to assure stable supply of electricity using the natural energies, preparation of social infrastructure such as power transmit networks, development of rechargeable batteries, smart grid systems is inevitable and should be accelerated.

28 Scenario of energy supply to achieve the low carbon society The operation of nuclear station (40 year duration)willceasein2049ifnonewplantis constructed. The substitution for nuclear energy is studied here with natural energy sources.

29 Case study on electric generation for 2020 Case Annual Power Generation (TWh/y) Nuclear Thermal Hydro Natural incl. PV Total CO 2 Emission (Mt/y) Case 1 is for 40 year duration of nuclear power plant. 2. Case 2 is for 30 year duration of nuclear power plant. 3. Cases 3-5 are for zero nuclear power.. 4. Total CO 2 emission in Japan in 1990 was 1141 Mt. Emission from electric generation in 1990 = 0.44 * 1141 = 502 Mt.. Yamada, K.: Lecture given at the Club of Rome (October, 2011)

30 Summary 1. Once a severe accident occurs in nuclear power plant, its influence is enormous and the cost of resilience from the damage is assessed to become tremendous amount. 2. Development of the use of natural energies should be accelerated. More application of natural energies is desirable. National policy is requisite to achieve this target. 3. It will be possible to establish the low-carbon society by 2020 by introducing solar cells and other natural energies. The scenario to establish the best mix of energy sources is shown. In this context, effort of energy saving is effective and inevitable. 4. The modest life style is desired for the people in Japan. Since the population is decreasing, it is advised that they should be satisfied by moderate growth or stability of GDP per capita, not of gross GDP.

31 Thank you for your kind attention!