Archive for March, 2011

31
Mar
11

Japan’s nuclear crisis

Geothermal, Nuclear Energy and Japan

The entire world’s attention is not on earthquake/tsunami disaster that struck Japan but on the energy crisis that plunged Japan due to the failure of all the 4 Fukushima nuclear reactors.  Japan will take a long way to recover from this disaster. But its immediate emergency is to bridge the energy supply gap that resulted due to the sudden shortage of 2.8 GWe. These 4 reactors generate 22 billion kWhr contributing 2.5 % of total Japan’s electricity demand. Now this shortage has to come from other energy sources like oil, coal, natural gas, solar, wind and geothermal etc etc!!.  Japan, although has large geothermal resources, the country overlooked this important source that could replace 100 % Japan’s planned nuclear power generation capacity in the coming decades.  The country can not ignore this important vast resource given the advantage of having all the turbine and geothermal power plant manufacturing giant companies, like Mitsubishi Corp., Fuji Electric, Toshiba etc, on its board

 Considering the time taken to recover from the disaster like the Fukushima, constructing geothermal power plants is much simpler option to put the power back in the grid. As on today Japan is generating 3000 GWh from 18 geothermal power plants contributing 0.3 % of total electricity production. 8 power plants are located in northern Japan and 4 of which are located in and around Sendai. 

The estimated geothermal potential is 24 GWe which the country should exploit now to tide over the crisis given the fact that geothermal power plant’s capacity is 95%- much higher than the nuclear!!

 As on 2007 data, Solar pv contribution was  2 GW  and by 2030 the country is planning to enhance the solar pv installed capacity to 100 GW.  However  the cost of solar pv is much higher compared to other renewables like geothermal. The current cost of solar pv is 20 US cents/kWh ( in USA the cost is 17 cents), while geothermal is  one fourth of this cost.

 When M 9.0 earthquake of Honshu disrupted normal life along the entire E and NE coastal regions of Japan, the question being asked is “ how safe are the geothermal power plants (GPP) in and around Sendai ?”  when the all the four Fukushima nuclear reactors ( ~ 4600 MWe generating capacity) yielded affecting a large number of people in the region. 

Nothing happened to the 4 GPPs located on either side of Sendai.  There are 8 GPPs located around Sendai region- 4 plants north of Sendai, 1 located south of Sendai and the remaining three located along the western coast, just opposite to Sendai region. 198 MWe of power is being generated by these power plants.  The power plants tripped immediately after the earthquake for couple of hours and resumed their normal capacity generation later. Hachijojima GPP, located in an island, south of the epicenter region hasnot been damaged and started functioning after a short break.

 With nuclear programme taking a back stem with Fukushima incident, Japan ca no longer ignore developing all its available green energy resources to its full capacity and put the country back on the fast track development. Japan example will be an eye opener to all other countries that has huge geothermal resources lying untapped.
 There are other safer options available to use nulear power plants in a safer and well cpontrolled manner. By constructing such large plants, countries, not only are endfangering their own people but also creating unwanted tragedy to other countries as well. Ther should be a lagislation to penalize such countries for disrupting other countries wealth and health.
Japan may be highly technologically advanced, but in the face of natural disasters, any country for that matter, have to accept that those technologies are inferior to those of nature.  It is surprising to note that there are nearly 52 nuclear reactors in Japan – a country fights day and night with earthquakes and volcanic eruptions. If such disasters are affecting their own country it is fine but affecting other countries’ developmental activity is not acceptable.

26
Mar
11

Myanmar earthquake

The Myanmar earthquake of magnitude 6.8 (USGS) that occurred near Kengtung, on 24 March 2011 at 13.55 UTC (7.25 pm IST), was a major earthquake of recent times in this region. The depth of focus reported was 10 km. According to the Chinese seismological observatory, the magnitude of the earthquake was 7.0 with the focus located at a depth of 20 km. The epicenter is located within Myanmar near the boundary of the three countries- Thailand, Vietnam and Myanmar.

 

The Seimological office in Myanmar recorded more than 6 after shocks of M5.0 and over 60 aftershocks of M<5. A major threat was to Srinagarind dam located in Thailand boardering Myanmar. However the dam was not affected.

 The earthquake resulted due to left-strike-slip movement of the Indian and Sunda plate along the Sagaing fault, a major N-S fault with a slip rate of 18mm/y. The Sagaing fault is a very active fault that hosted several earthquakes in the past including the 6.9 magnitude earthquake of February 1991.  The movement of the Indan plate with respect to the Sunda plate is about 45mm/y. The Sagaing faults continues south and transform into a series of transform faults in the Andaman Ses, east of the Narcondam and Barrend island volcanoes and joins ultimately the Sumatra fault. It is interesting to note that this fault was a loci of five major volcanic activity. Extint volcanic cones lies along the fault.

 Kengtung city was worst affected and a hospital in Tarlay was damaged. Over all deaths reported was 65 and 111 were injured.  390 houses were damaged, 14 monasteries and 9 gov. buildings were destroyed. 

The Chinese border (Yunan province) lies about 80 km from the epicenter. According to a local report from China and Myanmar, nearly 6500 people were affected in Yunan provinces by this earthquake.

24
Mar
11

Sendai earthquake

M 9.0 earthquake of Honshu, Japan disrupted normal life along the entire E and NE coastal regions of Japan. The question being asked is “ how safe are the geothermal power plants (GPP) in and around Sendai ?”  when the all the four Fukushima nuclear reactors ( ~ 4600 MWe generating capacity) yielded affecting a large number of people in the region.

Nothing happened to the 4 GPPs located on either side of Sendai.  There are 8 GPPs located around Sendai region- 4 plants north of Sendai, 1 located south of Sendai and the remaining three located along the western coast, just opposite to Sendai region. 198 MWe of power is being generated by these power plants.  The power plants tripped immediately after the earthquake for couple of hours and resumed their normal capacity generation later. Hachijojima GPP, located in an island, south of the epicenter region has not been damaged and started functioning after a short break. That is geothermal!!!

15
Mar
11

Sendai and Sumatra earthquakes and tsunamis.

The 8.9 magnitude Honshu earthquake of March 11, 2011,   occurred due to thrust faulting within the Japan trench. The tectonic configuration of Japan and its surroundings is very complex with 4 plates meeting just below Japanese islands. The islands lie over four plates: the Pacific, North American, Eurasian and Philippine sea plates. The Pacific plate  subducts into the Eurasian plate, the junction of these two plates lie just beneath Hokkaido and Honshu. This is the main Japanese trench and the rate of subduction of the Pacific plate is about 83 mm/year. The length of the Pacific plate is about 2000 km. Thus the geological and tectonic settings of the Japanese islands is very complex and at any given point of time one of these four plates move/thrust giving rise to major earthquakes. The depth of focus of the earthquakes varies from 700 km to 25 km or less.  The eastern margin of the Japanese islands, along the subduction zones is the loci of several active volcanoes.  The 1400 m high Shinmoedake volcano, located over this foci in Kagoshima Prefecture, Kyushu (southwest Japan) has become active after the Honshu earthquake throwing ash and rocks to a height of 4  km.

Earthquakes of this magnitude is not uncommon in and around Honshu. This is not a rare event that occurred at this site.  Over nine earthquake of magnitude >7 occurred in this area since 1973.  An earthquake of magnitude 7.8 struck in an area 260 km north of the 3/11 earthquake in the year 1994. This earthquake caused injuries to 700 people.  Similarly in 1978, an earthquake of magnitude 7.7 struck 35 km south west of the current 3/11 event. This caused injuries to 400 people. Besides this, 8.4 magnitude earthquake of Sanriku in 1933, 8.3 magnitude earthquake of Tokachi in 2003 are note worthy earthquakes in this region. All these earthquakes occurred due to thrust faulting below the Japanese Islands.  Between 9th March and 11th  March, 2011, Honshu experienced several foreshocks of magnitudes of  7.2 to 4.2. before the 3/11 earthquake. The main shock was followed by > 100 aftershocks and the after shocks are still rocking the region.

We have  witnessed two devastating earthquakes of magnitudes 9.1 ( Sumatra)  in 2004 and the recent 8.9 magnitude earthquake of Honshu accompanied by tsunamis. The Honshu tsunami occurred even before Sumatra tsunami faded out of our memory. The Sumatra earthquake occurred due to thrust faulting, similar to the one occurred in Honshu, where 1600 km long ocean plate fractured with a slip of 15 mts. The land near Banda Ache was lifted to a height of about 30 m. The tsunami generated due to this major event caused over 250000 deaths in Indonesia, Sri Lanka and India and causing dislocation of population in several coastal regions bordering the Indian Ocean. In the case of Honshu earthquake, the lateral shfit currently estimated is about 8 m. More data on the slip amount is being calculated. Both the earthquakes are shallow with the focus depth placed between 25-30 km. But the dimension of Sumatra earthquake and tsunami is larger by several factors compared to the Honshu earthquake. The Sumatra tsunami could travel 3500  km from the source caused devastating damage. A similar features was expected from Hnashu tsunami but the energy of the waves attenuated even before they could reach the nearby islands. The wave height measured at Hawaii islands, located at a distance of 6300 km from the epicenter was about 0.7 m.  

Majority of the earthquakes over Honshu occurred due to slip at shallow levels. The buildings in Japan are built strictly according to the codes. This is the reason one could see pictures in the television where tall structures in Tokyo were swinging at the time of the earthquake and returned to its normal poison. The death toll due to  earthquake in Sendai is far less compared to that due to the tsunami. We have to learn a lot from the Japanese civil engineers about making tall earthquake resistant structures. We do have codes on papers. Only an earthquake of magnitude half of that of Honshu will be able to prove how strong these structures are!!

The recent events all along the Pacific rim only demonstrates the dynamic changes that are taking place within the internal Earth system. We have a long way to go to  understand the dynamics of this system. Earth Sciences need to be given priority at school level itself, like other countries, to generate state-of-art younger generation of earth scientists to tackle such natural disasters in future. As far as Indian coast is concerned, the east coast is more vulnerable to tsunami related disasters as the coast is in line of sight of the grate Andaman-Nicobar-Sumatra – Sunda arc system. The west coast is not facing such arc system and hence chances of tsunami related disasters occurring are minimum. Only normal faulting, as evident from several earlier faults events, is a cause of concern, both on shore and off shore of the west coast, as reported in 1985 based on an integrated geophysical and geological analysis.

10
Mar
11

Solar PV long march ahead

If countries are dreaming of energy source mix with solar PV to mitigate carbon foot prints, it is a day dream. Countries have a long way to go to make solar PV affordable to common man.National solar mission may get derailed as banks hesitate to give loans for its high risk projects states a special report  in the recent edition of Down to Earth ( March 1-15, 2011).A mission without financial support is created. Newspapers, weekly magazines and all other print media talk about availability of large funds for solar power. The numbers run into crores!! Where are these funds? If funds are not available within the country under the solar mission scheme, how can entrepreneurs expect grants/loans from foreign financial institutions or investors?  The solar PV needs a break-though. Until then the unit cost of solar PV will stay high. The ground reality is different. The type of data required for the financial institutions to release funds are not available. Solar PV  is not just to keep a solar panel and generate electric power. There is science behind it and handful of entrepreneurs know about it!! The rest go with the tide and jump into the bandwagon. This is true with other non-conventional energy sources as well!!

Solar PV and wind are very popular in Sub-Sahara countries, although the unit cost is much higher compared to thermal. For example, the levelized grid supplied cost of solar PV is about 16 to 50 US cents in areas with good net work connectivity while the cost escalates to one dollar per unit in remote areas in Ethiopia.   Diesel generated power costs little over 70 US cents per unit. Thus diesel and solar PV are on par with each other as for as cost is concerned. The only difference is diesel has to be transported from the nearest sea port Djibouti, which is several hundreds of kilometers away from Ethiopia.

Compared to solar PV, geothermal power in Ethiopia is very competitive to all the renewable and with an estimated resources of 60000 MWe spread over the entire East African Rift  valley.The Aluto Lungano geothermal field alone is capable of generating 500 MWe. Unit cost of geothermal power is about seven US cents. The advantage here is to have local grid systems that can supply power to clusters of rural areas. Small geothermal power plants that can generate 5 to 10 MWe are most suitable and cost effective in the entire rift valley.  A 5 MWe geothermal power plant may need only one acre of land (1 acre is equal to 4047 sq. m or 43200 sq. ft). This is far less compared to the land requirement of solar. In future, with the hot dry rock technology taking shape, power can be generated in everyones back yard! Lets hope that this will happen before the next young generation retires!

Read the latest World Bank Policy paper WPS 5845 an 2012 “A Review of Solar Energy Markets, Economics and Policies”