Geothermal Power

In 1997, 'Kyoto protocol' says that industrialized countries will reduce emission of Green House Gases (GHGs) by at least 5% compared to 1990 levels by the period extending from 2008 to 2012. GHGs are vital because they act like a blanket around the earth. Without this natural blanket the earth's surface would be some 30 C colder than it is today. Human activity is making the blanket 'thicker'. For example, when we burn coal, oil, and natural gas we spew huge amounts of carbon dioxide into the atmosphere. If GHGs emission continue to grow at the current rate, it is almost certain that atmospheric levels of carbon dioxide will double from pre-industrial levels during the next century. If no steps are taken to slow greenhouse gas emissions, it is quite possible that levels will triple by the year 2100. The most direct result is likely to be 'global warming' of 1.5 to 4.5 C over the next 100 years. The most important key factor, the global climate, if altered, brings in changes over the entire world. The wind and rainfall patterns that have prevailed for hundreds or thousands of years, and on which millions of people depend, may change. In a world that is increasingly crowded and under stress -- a world that has enough problems already -- these extra pressures could lead directly to more famines and other catastrophes.

Consequence to the Kyoto protocol, all the industrial countries are encouraging development of new renewable energy technologies. Geothermal energy is gaining importance as alternate source of energy. Geothermal energy based power production over the world has gone up from 5800 MW to 8400 MW from 1998 to 1999. Thus all the countries, except India, have started using geothermal energy to generate power and support a variety of industries.

Nearly 70% of India's power production is based on coal due to the availability of huge coal reserves in the country. Excessive use of this source, without the use of strategies to mitigate its effects, will have deteriorating effect on the quality of human life. In another decade, according to the World Bank, emission of CO2, SO2 and Nx will exceed 1500 million tones, 1900 kilo tones and 1200 kilo tones respectively. This means CO2 emissions will be 775 million metric tones per year as compared to 1000 million metric tones per year produced in the entire European Union! This may lead to severe droughts, especially in developing countries like India, and reduce supplies of clean, fresh water to the point where there are major threats to public health. With global water resources already under severe strain from rapid population growth and expanding economic activity, the danger is clear.

Though India has been exempted from signing the Kyoto protocol, in future it has to be a part of this convention and reduce emission of CO2- which means reduction in usage of coal and other fossil fuels.

This is the time for India to launch its geothermal energy resources programme in a big way to implement clean development mechanism (CDM). The country has enormous resources, which are lying untapped. The country has the know-how and technology sources to generate power and support various industries using geothermal energy. Future for development of geothermal energy fits in very well under the above described Kyoto-FCCC. World funding organizations and developed countries, which are using extensively geothermal energy, are keen to promote this energy sources to reduce GHGs by India.

Why Geothermal Energy

There is no doubt that the cost of electricity produced from coal is far less expensive compared with other fuels. The present day cost of one unit of power is less than a rupee in the case of coal based power while liquid fuel based power costs about Rs. 2 per unit and hydro power costs about Rs. 1.50. But the expenditure spent to meet the consequences (like disposal of fly ash; treating the coal with high ash content etc) is high which automatically increases one rupee a unit to several rupees. Now a time has come to look into those alternate energy sources which were not viable a decade ago due to non availability of technical know-how. At present 1.5 percent of total power generation capacity comes from non-conventional energy sources like wind, solar and bio-mass. In the next fifteen years, according to the World Bank report, this energy supply could increase by seven times and above. Table 1 gives the present status of power production from non-conventional energy sources Geothermal energy which has a huge potential does not figure in the table!

Table 1. Power production status of non-conventional energy in India

The reasons for low targets achieved in this form of power sectors are many. For example, solar photovoltaic (SPV) is far less economically attractive than conventional technologies. For, the current estimated cost of SPV modules are around $ 4 to 5 Wp (peak watt). Assuming the cost to decline by 50% in future, the estimated cost would be around $2.5 Wp which is highly uncompetitive compared with $ 1.05 for other conventional sources. In the case of wind power, operational problems in matching demand and supply exists since the wind velocity is seasonal . The estimated cost of power produced using geothermal resources is less than Rs. 2 /kWh. Emission of CO2, SO2 by geothermal power plants is far less compared with conventional fossil fuel based power plants (Figure 1). Thus geothermal is quite competitive and eco-friendly and certainly improves the quality of lives in India.

Geothermal Provinces of India

Nearly 400 low to medium enthalpy thermal springs exists in India. These are distributed in seven geothermal provinces. The surface temperatures of these thermal springs vary from 47 to 98 oC. Total power generating capacity of these provinces is estimated to be of the order of 10,000 MW. The reservoir temperatures estimated based on water and gas geothermometers vary from 120 to little over 150oC. These provinces are the sites for commissioning small scale power projects using binary plant technology. They are also the best sites for “Direct” application technologies. Direct application technologies are those where the heat energy is utilized directly by a variety of small scale industries. Dehydration of agricultural produce and green house cultivation (food processing and food production) are two such industries to name, which can utilize this energy with maximum profits.

Technologies for Small Geothermal Projects

Small geothermal power plants such as binary power plants can be manufactured and can be operated in remote areas. Depending on the geographic locations of the areas such plants can be modified and made site specific. Since most of the resources which India has is of medium to low enthalpy in nature, binary power plants are most suited under such situations. The cost of small geothermal power plants depends significantly on power plant costs, drilling costs, resource quality and costs of financing. The expenditure for drilling and developing a geothermal well is "one time expenditure" and further cost for maintaining the equipment is minimum.

Finding Geothermal Resources for Small Scale Projects

An effective, economical exploration programme is essential to identify resources of sufficient quality in terms of temperature, depth and chemistry for the development of economically viable projects. In the case of Indian geothermal provinces, basic data on the chemical signature of the thermal waters and gases associated with the thermal waters already exists. An exploration plan for small geothermal plant sites should pool exploration risks across many small projects and identify a group of projects that will be logistically viable when bundled. Small projects cannot afford high drilling costs, such as $ 1-3 million per well spent during exploration for large projects. Drilling slim holes for exploration and production or using smaller more portable drill rigs are promising methods to reduce costs considerably. Conventional production wells have a maximum production zone diameter of 8.5 inches with a 7 inch slotted liner in the production zone. Slim hole, on the other hand have a production zone diameter of less than 6 inches. About 40-60% reduction in drilling costs can be achieved using slim hole technology.

Market for Small Geothermal Projects

Access to better energy technology could improve rural people's lives and small geothermal plants could be one of those technologies. Rural electricity services can be improved by installing individual systems, national grids and small mini-grids. In the case of remote areas where supplying power is uneconomical due to transmission losses and length of transmission line costs, small scale geothermal power projects becomes handy. With low per-capita electricity demands, typical of rural people in our country, this market may best served by many small generating units rather than fewer larger ones. Estimates made on other developing countries (like Latin America, the Caribbean and Philippines) indicate that at 100 watts per house hold (for lighting), 1 MW plant can serve about 10,000 house holds. We have similar situation in the hill states like Himachal Pradesh where small scale power plants are best suited and are cost effective.

Electric power sector reform is transforming the potential owners and operators of small geothermal projects from public utilities to private power producers. Reform is intended to improve the overall economic efficiency of the electric sector and may open new opportunities for small geothermal projects in this more competitive market. Systems for use of geothermal energy have proven to be extremely reliable and flexible. Binary power plants are on line an average of 97% of the time, whereas nuclear plants average only 65% and coal plants only 75% on-line time. Geothermal plants are modular, and can be installed in increments as needed. Because they are modular, then can be transported conveniently to any site. Both baseline and peaking power can be generated. Construction time can be as little as 6 months for plants in the range 0.5 to 10 MW and as little as 2 years for clusters of plants totaling 250 MW or more. One such binary power plant in operation at Wineagel Developers geothermal site in California, USA, generating 750 kW is shown in figure 2. This plant consists of two binary units with a gross efficiency of 8.5% and a capacity factor of 109%. Several such plants exists in China across Indian's border. The Yangbajain Geothermal Power Station in Tibet has an installed generating capacity of 25 MW ranking 10th in the world

Geothermal Industry Players in Small-scale Geothermal Market

Companies from USA, Europe, Japan, Iceland, New Zealand and developing countries will compete for profitable small geothermal projects in remote areas. If this market develops, the geothermal industry can provide the relevant technologies and experience for successful small projects. With the ongoing reforms in power sector, a large number of independent power producers are entering the power market over the world. Several major types of contractual arrangements for private power producers include BOO (Build-Own-Operate), BOT (Build-Operate-Transfer) and BTO (Build-Transfer-Operate).

Figure 2. Wineagel Developers geothermal plant (2 MW) at California.

Geothermal Energy and Food Processing Industry

'One of India’s proudest accomplishments has been achieving self-sufficiency in food production and that the country produces a wide variety of agricultural products at prices that are at or below world values in most cases'- states the office of the agricultural affairs of the United States Department of Agriculture (USDA). The Country's food industry's sales turnover at the end of the year 2000 was at US$ 31 billion. India’s food processing industry covers fruit and vegetables (onions, garlic, tomatoes, potatoes, peas; pineapples, bananas, apples, papaya, grapes and oranges); meat and poultry; milk and milk products, alcoholic beverages, fisheries (prawns, shrimps, tuna, cuttlefish), plantation, grain processing and other consumer product groups like confectionery, chocolates and cocoa products, soya-based products, mineral water, high protein foods and other products.

According to the official statistics of the Ministry of Food Processing, India exported processed vegetables and fruits worth US$ 2 billion in 1999-2000. India's food exports is about US$ 6 billion whereas the world total is about US$ 440 billion. Thus India is one of the world's major food producers but accounts for less than 1.5 percent of international food trade. Foreign investment, in food processing sector, after the economic liberalization stood at US$ 2 billion.

India's total food market is estimated at US$ 70 billion and value added food products would be worth US$ 22 billion. The total local production in the food processing sector in the year 2000 is estimated at US$ 1,240 million. India's total imports is estimated at US$ 400 million of which US$ 120 million are the imports from the U.S. because the food processing sector is lucrative for investment. India's diverse agro climatic conditions and also wide-ranging and large raw material availability throughout the year are suitable factors for the growth of food processing industry. In recent years processed food demand has grown considerably- especially from the middle-east countries. Realizing the potential of food processing industry, the government of India accorded top priority to this industry and announced several financial incentives to attract investors. Hence, there is large scope for U.S. companies to invest in food processing and packaging sector which is growing annually at 15 to 20 percent. If such is the situation, then why India is not able to cash it and be the world's best processed food exporter?

The problem lies in inadequate infrastructure like cold storage, dehydration facility etc. About 75-80 percent of vegetables and fruits in India perish due to high water content. This industry requires about US$6 billion in investment in the next five years to create necessary infrastructure, expand production and storage facilities using state-of-art technology to match international standards. Because of lack of such facilities products worth US$2.5 billion is wasted yearly out of which the farm products accounts for US$ 1.5 billion.

Using conventional energy to minimize wastage is expensive today and is going be the same or more expensive in future with ever increasing cost of conventional fuels.The cost of conventional fuel makes the finished product very expensive. To compete with international market and to promote the product in the local market, the amount spent in such process should be minimum. This can be accomplished by using the country’s available geothermal energy resources. To give an example, the table below gives a comparative statement of cost involved in dehydrating fruits using conventional energy and geothermal energy.

Courtesy: M/s Eco-Fruit Agro Industry, Gautimala, Central America: Cost in Rs.

Most food-processing and greenhouse operators over the world estimate that using geothermal resources instead of conventional energy sources saves about 80% of fuel costs – about 5% to 8% of total operating costs. Worldwide, the installed capacity of direct geothermal utilization is about 9000 MW and the energy used is about 31,200 GWh/yr distributed among 38 countries .

Note: Cost at places are mentioned in US$ since India has no previous experience in such projects.

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Also read "Clean Development Mechanism and Renewable Energy- India's perspective" By D. N.Yuvaraj Dinesh Babu, TERI

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