Red Sea Geothermal Provinces

D. Chandrasekharam, Aref Lashin, Nassir Al Arifi, Abdulaziz M Al-Bassam

• Publisher: CRC Press
• Year: 2016
• ISBN:
  9781317601173
• Edition: 1
• Topic: Physical Sciences
• Subtopic: Geology & Earth Sciences

"Today, over two billion people in developing countries live without any electricity. They lead lives of misery, walking miles every day for water and firewood, just to survive. What if there was an existing, viable technology, that when developed to its highest potential could increase everyone's standard of living, cut fossil fuel demand and the resultant pollution" said Peter Meisen, President, Global Energy Network Institute in 1997. Even though energy is available, technology was not matured enough to tap this energy in the nineties. Now, with the advancement of drilling technology, extracting heat from hot rocks has become a reality. Very soon when CO2 replaces the circulation fluid to extract heat from granites then both fossil fuel based and renewable energy sources will coexists balancing the CO2 emissions and providing energy, food and water security to the rich and the poor countries.

Red Sea rift represents the youngest spreading ridges in the world with a vast amount of heat energy stored on either side. The Red Sea is surrounded by countries with a weak economy. Developing a geothermal energy based economy in countries like Eritrea, Djibouti and Ethiopia will provide food and water security to these countries while for other countries, geothermal energy will help in mitigating greenhouse gas emissions. Although geothermal energy sources are available in all the countries since the opening of the Red Sea, millions of years ago, this was not brought to the light. Oil importing countries became highly dependent on the oil rich countries to sustain their economy and growth and thus remained poor.

This book unfolds the huge energy source, hydrothermal and EGS, for the benefit of the poor countries to reduce poverty and lift the socio economic status of these countries. The book deals with i) future energy demand, ii) CO2 emissions associated with fossil fuel based power plants, iii) black carbon emissions associated biomass energy source and iv) strategies to reduce CO2 emissions by using geothermal energy as energy source mix in all the countries—oil exporting and oil importing countries— around the Red Sea. The amount of energy available from hot granites in all the countries is well documented. EGS being the future energy source for mankind, this book will form the basis for future research by young scientists and academicians.

Availability of fresh water is a matter of concern for all countries. The only way to satisfy the thirst of a growing population, to meet drinking water demand and food security, is to depend on seawater. A large volume of CO2 is being emitted from desalination plants supported by fossil fuel based energy sources. This book describes the advantages of using geothermal energy sources for the desalination process to meet the growing water and food demand of the countries around the Red Sea. Oil rich countries, using its geothermal resources, can now reduce food imports and become self sufficient in food production.

This book gives hope for millions of children living in the underdeveloped countries around the Red Sea to satisfy their hunger and live a decent life with a continuous source of electricity, water and food available. This book ends with a note on the economic benefits of geothermal energy vs other renewables. With the signing of the GGA (Global Geothermal Alliance) by several countries during the December 2015 CoP 21 summit in Paris, policy makers and administrators will work together in implementing the necessary infrastructure and support to develop this clean energy source.

Chapter 1

Introduction

There is reason to be optimistic about geothermal energy. The exciting period is beginning where anomalous sources of heat are treated as systems. To develop geothermal energy as an important resource one must identify anomalous thermal sources and understand their genesis and geometry.

Grant Heiken, Los Alamos National Laboratory

Under the 6D scenario, following the business as usual trend, oil remains the most important primary energy source. Another three decades from now, under this scenario, global energy demand will grow by 70% and CO₂ emissions will grow by 60%. This trend is disastrous for the economies and future generations will be forced to live in an unpleasant environment. Curtailing the use of oil and supplementing it with renewable energy sources may improve the situation, but unabated use of old coal based thermal power plants and failure to implement clean coal technology based power generation systems will undermine this situation. Efforts made by all the countries to counter the effects of the 6D scenario will be fruitless if control over coal is not exercised. Electricity being the primary demand for all economies, a system that can substitute this primary energy should be able to generate baseload power with 97% efficiency and a minimal lay-off period while simultaneously reducing CO₂ emissions. Countries under the Intergovernmental Panel on Climate Change (IPCC) convention of Parties (COP) meetings are not able to pledge to reduce use of fossil fuels primarily because of the underdevelopment of a robust electricity generating renewable energy source that has zero carbon foot print. Technological advancement made over the last decade is giving hope to achieve the 2D scenario by 2030. This hope will become reality only when dependence on fossil fuels shows a declining trend. According to the Energy Sector Carbon Intensity Index (ESCII), if the business as usual scenario continues, making 6Ds as the expected emissions in 2050, then the world is calling for a disaster (Figure 1.1). According to the Energy Technology Perspective 2014 (IEA, 2014e), electricity generation through renewable energy sources is on track and making convincing progress. Thus, there seems to be some hope to bend the CO₂ emissions curve by 2050 (Figure 1.1). Between 2006 and 2013 electricity generation grew by 5.5% and was expected to reach 40% in another five years. This means the renewables will be able to generate about 6850 TWh by then.

Generation costs are posing a challenge to meet 2D’s from renewable energy sources. Although renewable energy sources, other than geothermal, are being discussed at length, given wider incentives, encouraging cost reduction in manufacturing the necessary components, they are not able to make substantial progress when levelised costs are considered. The levelised cost of electricity from various renewable energy resources published by IEA (2014e) is shown in Figure 1.2.

Figure 1.1 Carbon intensity index showing the influence of renewables in the three scenarios (6D: six degrees, 4D: four degrees, 2D: two degrees; adapted from IEA, 2014e).

Figure 1.2 Levelised cost of electricity from renewable energy sources (IEA, 2014e).

Although solar photovoltaics (PV) and Concentrated Solar Power (CSP) are reported to be surging ahead of other renewables, with double digit growth and pushing the global share of renewables to 20% (IEA, 2014e), the levelised cost either for solar PV (residential and utility) or CSP is not able to compete with geothermal energy. In fact, new coal technology is still able to be the leader in 2050 and hence coal will rule the electricity domain even after two decades. Perhaps this may be due to the large land and water requirements for solar PV compared to geothermal energy sources. Geothermal power plants need 1 acre/MWe (4047 m²) while solar PV and wind power need 7 and 2 acre/MWe (Chandrasekharam et al., 2014a). Once the enhanced geothermal systems (EGS) technology matures, the geothermal energy source will be a zero carbon source, and with CO₂ being used as the circulating fluid to extract the heat, this technology will have a double advantage of controlling CO₂ emissions and generating electricity as well. This may even help coal based thermal plants to continue their operation without counteracting the emissions progress under the 2D scenario. Among all the renewable energy sources, geothermal energy alone can supply baseload electricity and does not require any backup support unlike other renewables. To meet the 2D target (Figure 1.1), countries have to work hard to bring down the CO₂ emissions per unit of electricity by 90% by the targeted date. This target reduction is possible by using geothermal energy sources as the primary source in the energy mix because the CO₂ emissions by geothermal energy power plants is only 0.893 kg CO₂/MWh while oil based power plants emit 817 kg CO₂/MWh and gas based power plants emit 193 kg CO₂/MWh (Chandrasekharam and Bundschuh, 2008). The countries that have easily accessible geothermal energy source like Eritrea, Djibouti and Yemen can adopt policies to include this as a primary energy mix for electricity generation. These countries heavily depend on imported fossil fuels to support electricity generation and transport, thereby increasing their energy security risk as well as their food security risk due to the supply volatility of oil. Those high temperature geothermal systems lying untapped, as discussed in this book, if developed, can make a difference in the socioeconomic growth of the country in terms of access to cheap electricity, water, and also help the country in reducing CO₂ emissions and earn carbon credits. Saudi Arabia on the contrary, can offset part of its fossil fuel use for electricity generation by using its geothermal energy sources and reduce CO₂ emissions. It can also save additional CO₂ by using geothermal energy sources for its desalination processes and provide fresh water for the growing population in the future, for drinking and agricultural purposes. The emissions reduction strategies of these countries have been adequately deliberated in this book. Thus both oil exporting as well as oil importing countries have the opportunity to be energy independent and reduce food imports and become food secure countries. In all the countries discussed in this book, except Saudi Arabia, a large population lives in rural areas that have no proper infrastructure to improve its socio-economic status. For example, the urban population in Djibouti has access to electricity and water. Those living in remote places like in Lake Abhe Bad, have no access to electricity and live in poverty, while this site has plenty of geothermal energy sources that can support millions around the lake.

All the countries around the Red Sea, except Eritrea and Egypt, receive very low rainfall and lack proper surface drainage systems. As a result, these countries are stressed for water and affluent countries, like Saudi Arabia, desalinate the sea water to meet fresh water demand for drinking and for agricultural purposes. To date Saudi Arabia utilises 17 million kWh of electricity to meet a 235 L/day fresh water demand for its 29 million population. At present about 33 desalination plants are in operation in Saudi Arabia (Chandrasekharam et al., 2014a). With a 6% annual population growth, by 2030 the demand for the additional electricity needed to generate fresh water will increase manifold. This will has an effect on CO₂ emissions. These countries around the Red Sea are fortunate to have active volcanic and rift systems and an active and young spreading centre in their neighbourhood that can supply heat for decades. While the world is debating on the reduction of emissions by 2030 and 2050, these time spans, on a geological time scale, are fractions. These countries can evolve better systems of living with improved socio-economic and carbon free environments for centuries. As discussed in this book, the hydrothermal systems have evolved since 31 Ma while the high heat generating granites have evolved since 900 Ma. These countries can set an example as leaders in the world in evolving carbon mitigation strategies by using geothermal energy sources.

The countries around the Red Sea experience extreme weather conditions, where, especially in summer the temperatures reach > 40°C and hence a huge amount of electricity is consumed to support air conditioning and ventilation systems. More than 70% of electricity is consumed for space cooling by Saudi Arabia (WEO, 2012). Use of fuel oil and direct combustion of crude oil to generate electricity to support space cooling has resulted in extremely low average power plant efficiency and excess emissions of CO₂ (WEO, 2012). Because of subsidies given for electricity, individual incentives to deploy more energy efficient systems have eroded there, resulting in huge energy wastage. Although the initial capital cost of geothermal energy is higher than other renewable energy sources, in the long term, these costs are absorbed since the systems work for many years, supplying baseload power with least down time and low maintenance costs (Figure 1.2). In addition, the fuel’s cost, unlike the fossil fuels, is zero.

Besides electricity, the countries around the Red Sea face severe problem of fresh water shortage to support agricultural activity. For example, Yemen experiences increasing aridity due to climate change and the demand for water for agriculture and urban needs is ever increasing. Like energy, the water requirements will grow manifold in the future. Countries located in semi-arid zones are vulnerable to four types of water scarcity, of which two are natural and two are induced. This scarcity, when fuelled by intense population growth, escalates and manifests itself in socio-economic collapse (Falkenmark, 1989). However, solutions to such problems are at hand and it is up to an individual country to realise the solution and execute it. Yemen imports 100% of its food and the country’s staple diet is wheat and rice. Because of this, the country faces food insecurity and child and maternal malnutrition is highest in this country compared to other countries in the world (WFP, 2010). In addition to this, the country has a high population growth (> 3%/year), high poverty rate (35%) and poor infrastructure. Nearly 96% of the population are net buyers of food and are susceptible to fluctuations in the global food market. The situation is similar in Djibouti. In 2005, due to a worldwide increase in commodity prices, the purchasing power of individuals in Djibouti decreased drastically, gripping the country in poverty. Although the report (WFP, 2010) states that the country lacks natural resources, it is the inability of the government to develop its huge geothermal resources and the reluctance of the donors to help the country to realise its natural resources which have downgraded the country’s ability to come out of the poverty and become energy and food secure (WB, 2012). Geothermal energy sources are plenty available around Lake Asal and Lake Abhe Bad, where exploratory and pilot power plant works were conducted and proved the capacity of the resources. 1 MWe (8 million kWh) of electricity can support about 6000 people (Vimmerstedt, 2002, Chandrasekharam and Bundschuh, 2008), and the Djibouti geothermal sources have the capacity to generate more than this quantity. Had the amount of financial aid the country obtained been utilised for developing these natural resources, the country could have become energy independent and food secure.

The situation in Saudi Arabia is different. The country has abundant oil and gas resources and controls the world economy. However, its inability to control excess utilisation of fossil fuels, not adopting energy efficiency systems, and not developing its geothermal energy sources, is causing drastic climate related problems in terms of flash floods and a continuous increase in air temperature due to excess CO₂ emissions. The country’s staple diet is wheat and barley that are grown in the west coast through irrigation. Small check dams and shallow groundwater resources support agricultural activity in this region. Domestic water supply is supported through desalination plants. The fresh water demand in Saudi Arabia is about 19 billion cubic metres (BCM) with 83% of the demand being from the agricultural sector. The country produces about 2 BCM of desalinated water annually from fossil fuel based processing plants (Chowdhury and Al Zahrani, 2015). With growing demand from the domestic and industrial sectors, restrictions are imposed on the agricultural sector to decrease domestic production and increase imports of staple food. From 2016 onwards, the country will adopt a policy of importing the entire domestic demand of wheat and barley and phasing out domestic production of these food items. The fresh water demand for agriculture can successfully be accomplished by generating fresh water through a desalination process using the currently available hydrothermal resources in Al Lith and Jizan (Lashin et al., 2014, Chandrasekharam et al., 2015b). In addition to fresh water, additional electricity can also be generated through this process. The feed water in desalination plants need not only be sea water (Figure 1.3). However, agricultural return water, wastewater, and brackish water as feed water for desalination plants may reduce the cost of desalination and reduce the power consumption.

Figure 1.3 Feed water in desalination plants (adapted from Mezher et al., 2011).

In addition to the domestic and agriculture sectors, water is also required for energy production. Over 583 BCM of water were consumed by the energy sector in 2010 and by 2030 consumption will increase by 85% (IEA, 2012). This demand is apparently linked to the growth in population and the need to increase GDP growth through industrial activities (IEA, 2012). The fossil fuel and nuclear powered plants consume significant amounts of water. Water is also required to irrigate crops to support biofuels based power plants. Further, solar PV panels use water for cleaning to maintain production efficiency in countries like Saudi Arabia (Segar, 2014). Solar PV desalination plants operate at 20% efficiency and can generate 5000 cm³/day of fresh water (Ahmad and Ramana, 2014). The water requirement of geothermal power plants is low and these power plants can generate fresh water for their own consumption.

Hence the above countries face two challenges: 1) to have a guaranteed electricity supply to meet ever growing demand and 2) to reduce CO₂ emissions. Guaranteed electricity will ensure water and food security and CO₂ emissions reduction will ensure sustainable development. No doubt, there are other options too that can meet these two challenges. Nuclear energy is one option that will meet both the challenges, but increasing global concern is a hindrance to its future accelerated growth. Hydropower development is beset with environmental concerns. Changes in weather patterns (poor rainfall) due to global warming is causing severe setbacks to already existing dams. Solar and wind power are other options, but they cannot supply baseload electricity and solar PV, as mentioned earlier, they need a large land area, while both solar PV and wind need back up power support. Biomass is yet another option, but biomass emits black carbon which is more harmful than carbon dioxide. The rural populations in Ethiopia, Djibouti, Yemen, and Eritrea depend on biomass to support their energy requirements. The black carbon affects the people around the source causing severe health related issues. However, this source was never given serious consideration. Thus, biomass is not a comfortable renewable energy source. The question is, what should be the criteria for considering renewable energy as the future energy, to meet growing demand and meet the 2D scenario? The following are the criteria: a) the source should be large enough to support long lasting energy supply to generate electricity and meet the present and future demand, b) the source should be easily accessible and economically viable, c) the source should be available over a large geographical boundary, d) the source should have the least carbon foot print and e) the source should be able to support baseload electricity supply without any backup support. Geothermal energy meets all the above criteria. Now that EGS technology is maturin...

Table of contents

• Cover
• Half Title
• Title Page
• Copyright Page
• Table of Contents
• Foreword
• Authors’ Preface
• About the authors
• Acknowledgements
• 1 Introduction
• 2 Electricity demand and energy sources
• 3 Carbon dioxide emissions
• 4 Geothermal provinces
• 5 Carbon dioxide mitigation strategy
• 6 Geothermal exploration techniques
• 7 Power generation systems
• 8 Direct applications
• 9 Enhanced geothermal systems
• 10 Economics
• References
• Subject Index