Future Energy

Improved, Sustainable and Clean Options for our Planet

Trevor Letcher, Trevor M. Letcher

• Publisher: Elsevier Science
• Year: 2013
• Print ISBN: 9780080994246
• eBook ISBN: 9780080994222
• Edition: 2
• Topic: Technology & Engineering
• Subtopic: Environmental Management
• Index: Technology & Engineering

As the demand for global energy increases, fact-based evaluations of alternative energy sources are needed in order to address the growing interest in how energy is produced, provided, and transported in sustainable ways. Future Energy, Second Edition provides scientists and decision makers with the knowledge they need to understand the relative importance and magnitude of various energy production methods in order to make the energy decisions needed for sustaining development and dealing with climate change. The second edition of Future Energy looks at the present energy situation and extrapolates to future scenarios related to global warming and the increase of carbon dioxide and other greenhouse gases in the atmosphere. This thoroughly revised and updated edition contains over 30 chapters on all aspects of future energy, each chapter updated and expanded by expert scientists and engineers in their respective fields providing an unbiased and balanced view of the future of energy. - Provides readers with an up-to-date overview of available energy options, both traditional and renewable, as well as the necessary tools to make informed decisions regarding selection, use, and environmental impacts. - Covers a wide spectrum of future energy resources presented in a single book with chapters written by experts of the particular field - Eleven new chapters including chapters on: solar heating, energy resources in developing nations and frontiers in oil and gas, Arctic drilling and unconventional oil and gas sources, thorium in nuclear fission, ethanol and other options for future transport fuel, fracking, smart grids, new batteries, environmental issues and the energy options for China

Part I

Introduction

Outline

Chapter 1 Introduction with a Focus on Atmospheric Carbon Dioxide and Climate Change

Chapter 1

Introduction with a Focus on Atmospheric Carbon Dioxide and Climate Change

Trevor M. Letcher*, Chemistry Department, University of KwaZulu-Natal, Durban, South Africa

In this chapter, we look at

• driving forces behind the need to consider new forms of energy,

• the looming problem of global warming and climate change,

• the options for electricity generation and for transport fuel,

• the energy situation today,

• the big question: How can we reduce the stranglehold that fossil fuels have on our economy and lives?

The energy choices we make will depend on where we live, the size of our population, and also on the types of energy sources that are available. For example, people in Iceland beyond any doubt will consider expanding their renewable sources of geothermal and wind energy, whereas those living in South Africa will certainly consider solar energy, among many other possibilities. At the same time, account should be taken of the polluting nature of the energy source and it is our responsibility to assure that whatever energy source we utilise, we do it in an environmentally sound manner. And if one cannot steer totally away from fossil fuels the resultant carbon dioxide and other pollutants should be either sequestered and stored or utilised and not emitted to the atmosphere.

Keywords

sustainable non-polluting energy; anthropomorphic carbon dioxide; climate change; atmospheric pollution; electricity generation; transport fuel

1.1 Why is it Important to Consider Our Future Energy Options?

1.1.1 Society’s Needs

As the population of the world increases and as developing countries advance, so energy needs increase. The world’s population is increasing – it was 3 billion (3×10⁹) in 1960, 6 billion in 2000, 7 billion in 2010, and is expected to reach between 9 billion and 10 billion in 2050. The annual rate of population growth reached a peak of 2.2 %·a⁻¹(where ‘a’ refers to annum) in 1963, but by 2011 it had declined to 1.1 %·a⁻¹[1].

The expected growth rate in energy demand over the next 20 years is much greater than the growth rate of the population and this is largely due to increased electricity production by developing nations. The electricity generation is expected to increase from 20×10¹⁵ W·h in 2010 to 31.2×10¹⁵ W·h in 2030, which is equivalent to an average energy increase of over 5 %·a⁻¹[2]. This additional energy supply must be found and preferably in the form of renewable energy.

1.2 The Need for a Sustainable, Safe and Non-polluting Energy Source

The present world energy supply is dominated by fossil fuel (Table 1.1), which unfortunately is not sustainable in the long term. Combustion of fossil fuel is a major cause of air pollution, and because of this it can be argued that fossil fuels are not a safe form of energy. The picture is confusing because we are living in an age with an apparent glut of fossil fuel. Coal and conventional gas continue to be relatively easy to extract. Unconventional gas has experienced a recent boom because of horizontal drilling and hydraulic fracturing techniques. At the same time, oil is becoming more and more difficult to extract in spite of new drilling techniques. The need for a sustainable, safe and non-polluting liquid fuel for vehicular transport is of particular concern as the transport and production of oil can create serious environmental problems, and names such as Exxon Valdez (1989), Torrey Canyon (1967), Nigerian Delta (1970–2000) and Deepwater Horizon (2010) have become bywords for environmental disaster.

Table 1.1

Total Global Energy Consumption Percentages for 2010 [3,4].

Type of Energy	Energy Consumption/%
Oil	35.3
Coal	27.0
Natural gas	20.5
Nuclear	5.0
Hydroelectric	5.8
Biomass	6.3
Other renewable	1.1

With the recent development of shale gas reserves, especially in the United States, there has been a shift in thinking about exploiting fossil fuel. The argument is that burning natural gas (largely methane) is better for the planet than burning coal. This is true because the amount of CO₂ produced from burning CH₄ per unit energy (50 g·MJ⁻¹) is less than it is for coal (92 g·MJ⁻¹) and moreover coal burning produces particulates. But burning CH₄ still produces CO₂:

and contributes to climate change.

Replacing fossil fuels is going to be a mammoth task. At present, energy sources other than fossil fuels make up about 20 % of global energy consumption (Table 1.1). These include nuclear fission, hydroelectricity, biomass, and renewable sources, such as wind, solar, geothermal (Chapters 9, 15–22).

Replacing gasoline, diesel and aviation fossil fuels is going to be an even bigger task. The reality is that we do not have an alternative, viable and convenient energy source for transport. The importance of transport fuel and the magnitude of the problem are highlighted in Table 1.2, which shows that of all the energy used on Earth today, transport makes up 31 %.

Table 1.2

Energy Usage as a Percentage [5].

Sector	Energy Used/%
Transport	31
Industrial	14
Electricity production	38
Commercial/residential	10

Attempts at replacing gasoline in transport with a renewable fuel derived from biomass (sugar cane and corn) has had some success but the overall contribution has been relatively small. In 2011, biofuels contributed about 3 % of the world’s transport fuel, with the ethanol production of United States and Brazil being the major contributors [6].

1.3 Climate Change

Perhaps the most important driving force to finding new sustainable energy sources is linked to the spectre of climate change. Climate change and global warming are considered to be a result of anthropogenic greenhouse gases (GHGs) with CO₂ being the most important. More details of the relationship of CO₂ levels and global warming are given in Section 1.2.

The level of atmospheric carbon dioxide has been steadily increasing. It was 280 × 10⁻⁶ (parts per million, ppm) in pre-industrial times, about 315×10⁻⁶ (ppm) in 1957 and on 10 May 2013, the atmospheric levels of carbon dioxide reached a new high of 400×10⁻⁶ (ppm) [7].

For a few decades now, world leaders and environmentalists have been talking about limiting the average global temperature rise to no more than 2°C higher than pre-industrial temperatures (Chapters 30 and 31). At the rate at which CO₂ is presently being emitted into the atmosphere (6 Gt·a⁻¹), and at the rate that the average global temperature is increasing (0.2°C·a⁻¹), this will be passed in less than a 60 years from now. The rationale behind this 2°C per year increase is that we could possibly live with this level of temperature rise, but any further increase might tip the balance, plunging the world into climatic feedback loops which will be difficult to stop. The predictions of catastrophic droughts and floods, rising sea levels, melting ice caps and ice sheets, wholesale migration of populations, serious drop in food production, and overcrowding in cities which will probably accompany a temperature rise of greater than 2°C should be enough to galvanise governments and societies into finding alternative energy sources [8,9]. I say ‘probably’ because the truth is that we just do not know. It might be that 1°C increase is too much, or that with 2°C the changes will be not as severe as predicted. The fact is that the current average global temperature is 0.8°C higher than pre-industrial temperatures.

The question one may ask is ‘Why can’t we convert CO₂ into useful products such as plastics?’ The problem with CO₂ is that it is not easily transformed into other chemicals. It is the most oxidised form of carbon and as a result is thermodynamically very stable and hence any chemical reaction involving CO₂ will require a significant input of energy. In short, it has a large and negative Gibbs energy of formation. Perhaps, the only viable way to get rid of it is to collect it and store it (Chapters 26 and 31).

Electricity production is res...

Table of contents

• Cover image
• Title page
• Table of Contents
• Copyright
• Preface
• List of Contributors
• Part I: Introduction
• Part II: Fossil Fuels (Energy Sources)
• Part III: Nuclear Power (Energy Sources)
• Part IV: Transport Energy (Energy Sources)
• Part V: Transport Energy (Energy Storage)
• Part VI: Renewables (Energy Sources)
• Part VII: New Possible Energy Options
• Part VIII: Environmental and Related Issues
• Index