02
Aug
14

Geothermal and the world today

“Geothermal energy has great growth potential as it is limitless and available in almost every corner of the globe”…….said a geothermal scientist working with the Chinese Academy of Sciences. According to the country’s 13th five year plan target annual geothermal utilization should reach 50 million tons of standard coal equivalent by the end of 2020. The country is focusing on reducing use of coal by geothermal source for space heating and cooling. The country has already demonstrated its capability in the 2008 Olympic games where its foot ball ground, swimming and residential complex for the athletes utilized geothermal energy. Sothern region of China, along the Himalayas, is a huge geothermal hub. Its pilot plant in Yangbajing is working since several decades. Very soon, with EGS technology maturing, the entire Tibet will be powered by geothermal. Knowing its future, a large number of Chinese companies are establishing geothermal market in China. All these things are happening with the government support. Compared to other countries like Japan, India, Mangolia, Indonesia, the geothermal resources in China are limited confined mostly in sedimentary formations at depths varying from 1 to 2 km with average geothermal gradient. .

Earlier USA on 9th July passed the Geothermal Production Expansion Act of 2013 unanimously. This facilitates non-competitive leasing on land next to the existing geothermal sites. “Geothermal energy is a reliable and renewable source of energy that has the potential to help move us to a cleaner energy future,” Senator Merkley said. added. “We should be doing everything we can to boost production of innovative, affordable, and renewable domestic energy sources” said Merkley. While requesting the House to pass the bill Senator Ron Wyden said “I encourage my colleagues on the House side to pass this bill………….geothermal developers can get development rights at fair market value without having to wait for lease nominations or speculators driving up the price of leases”

In Kenya’s power sector a new era has emerged. The World Bank is stepping in to bring financial aid from financial sector to develop geothermal. US$ 166 million Partial Risk Guarantees is in place to develop geothermal. The International Finance Corporation is lending long term debt for geothermal. With this future expansion plan, Kenya will have surplus electricity and will be in a position to support other neighbouring states like Uganda and Tanzania…..or perhaps the entire East African countries. This will, to a large extent, change the socio-economic status of all the East African countries. Countries like Uganda and Tanzania have considerable EGS to support their future energy demand. Once this source is exploited, the East African countries will become energy independent and have tremendous opportunity to enhance their GDP.

Although India has greater geothermal resources compared to China, and that too at shallower levels, the country is slow in exploiting this energy source. Constant efforts and meetings with public and private sector entities by M/s GeoSyndicate, the country is now slowly realizing the advantages of geothermal source in reducing CO2 emissions by using GHPs for space heating and cooling. These are small pilot setups. What the country needs is electricity to meet its ever growing demand from industries and commercial establishments. Many of the geothermal sites in India is in rural areas and these sites provide excellent opportunity to uplift the rural population economic status. What the country needs is energy source mix to mitigate problems related to environment and power shortage. Often our scientists at large take myopic view (either because of ignorance or unawareness) in addressing the issues related to rural development and focus on only biomass and other sources even though geothermal is easily accessible and cost effective and saves the rural population’s health in several rural regions. These scientists are capacity builders in well reputed institutes. The pressing problem in rural India is generation of BC (Black Carbon) that affects the health of women and children and also the environment.

Coal, fuel wood, dung cake and agricultural waste are consumed maximum in that order in rural India. According to 1996-2011 data, 286 Mt (million) of coal, 302 Mt of fuel wood, 121 Mt of dung cake and 116 Mt of agricultural waste were consumed in India.  The consumption of these fuels has increased by several folds due to increase in population and demand. BC emission factor of these fuels in that order is ~ 0.8, 1.1, 4.4 and 1.3 g/kg. BC  absorbs sunlight turning it into heat. Thus, a layer of BC in the atmosphere, while emitting a third of this absorbed heat back in to space, keeps the earth’s surface warm. More BC in the atmosphere means more heat over the surface of earth. As the BC increases the earth’s surface gets hotter and hotter!! Simple logic.  Thus BC causes change in the heat input at the top of the atmosphere. This is known as “Radiative Forcing (RF)”.  According to the Intergovernmental Panel on Climate Change (IPCC) 2007 report,  RF of BC is of the order of + 0.34 W/m2 while forcing of CO2 is of the order of + 1.66 W/m2.

 

Let us take the example of Leh, a village in Ladakh that experiences extreme temperature variations. Population of Leh is ~ 68,000 and with the reported per capita BC emission of 600 g. Leh alone is contributing minimum of about 0.04 Gg of BC annually. Similarly, Kargil with a population of 119,307 is contributing about 0.07Gg of BC to the atmosphere around the glaciers. A similar emission figures can be assumed from other towns located at that altitude all along the higher Himalayas, extending from NW to E of India. The BC emission from the foot hill Himalayas also reach higher altitude. During winter ( where BC emission is maximum) snow brings down all the BC floating in the atmosphere. This is the reason why many Himalayan glaciers appear black. It is easy to estimate the BC content in ice. Since it is possible to date ice, BC content in the atmosphere in the past can be estimated. The Gangotri glacier is retreating at a rate of 18 m/yr. This is really alarming and this observation is not disputed. The real “component” that is responsible for this retreat is BC. Simulation studies conducted by Lawrence Berkeley National Laboratory showed that major contributor (~90%) for fast melting of glaciers is BC.

China has realized these issues and embarked on a massive programme to reduce the use of conventional energy sources for many of its rural and urban community system by amending its energy policies like the European countries. China, by 2020 will be able to achieve the targets of CO2 emissions set by IPCCC.