[Evans, in a detailed review in 2007, assessed the value of sustainable energy, and indicated that coal will be with us well into the 22nd Century. Will looking back now help us look ahead with renewed confidence?]
Evans indicates in his Preface to his 195-page text that energy use, and its impact on the environment, is one of the most important technical, social, and public-policy issues that face mankind today (2007). There is a great deal of research, and many publications, which address these issues, some of which paint a very pessimistic picture for future generations, while others point to a bright future through the use of new technologies or the implementation of new policies.
Although a lot of excellent work is being conducted, much of the research necessarily tends to be quite narrowly discipline-based. Solutions to the problems caused by current patterns of energy use therefore often appear to be somewhat piecemeal in nature, and it is difficult for decision-makers and energy consumers to see the ‘‘big picture’’ which is really needed to understand and design truly sustainable energy processes. This book takes a systems approach to energy use, so that the complete consequences of choosing a particular energy source, or energy conversion system, can be seen. The concept of the complete energy conversion chain, which is a simple but powerful tool for analyzing any energy consuming process, is introduced to link
primary energy resources through to the ultimate end-use. Looking at the complete consequences of any proposed energy technology in this way enables the reader to see why some proposed solutions are more sustainable than others, and how the link between energy consumption and greenhouse gas emissions can be broken.
This simple systems approach is essential to provide a global understanding of how we can begin the transition to a truly clean and sustainable energy future. The environmental consequences of energy consumption and current energy use patterns are then summarized, providing the necessary background needed to understand the extent and complexity of the problem. Subsequent chapters outline the current state-of-the-art
in sustainable energy technology, including non-conventional fossil fuels, renewable energy sources, and nuclear power. The challenging problems of developing a more sustainable transportation energy system are addressed in some detail, with a particular focus on road
vehicles.
Finally, some projections are made about how a sustainable global energy balance might be achieved over the remainder of this century. It is hoped that this book will be a valuable and thought provoking resource not only for energy practitioners and students, but also for decision-makers and the interested public at large.
Evans concluded that if, for some reason, the use of nuclear power and renewable energy does not expand to the extent assumed in the Nuclear and
Renewable Energy Scenario, another alternative for enabling the transition to an electricity economy is the ‘‘Clean Coal Scenario.’’ In this scenario, coal use would be greatly expanded, and would be used primarily to generate electricity, and perhaps also to produce synthetic liquid and gaseous fuels. In order to reduce greenhouse gas emissions, the use of ‘‘clean coal’’ technology, together with carbon sequestration would need to be widely implemented. New coal-fired powerplants would likely be based on the IGCC approach (as described in his Chapter 6), leading to increased efficiency and reduced emissions. Additionally, the carbon dioxide generated by such plants would need to be ‘‘sequestered,’’ using carbon capture and storage techniques which are still in the earliest stages of development. This aspect of clean coal technology is probably the least well developed at the present time, and much more work needs to be done to determine if it will be technically and economically viable on the very large scale required to sequester most of the CO2 produced.
Although preliminary trials of carbon sequestration have been undertaken, (as discussed in Chapter 6), much more work needs to be done to determine if there really are enough suitable repositories for the long-term sequestration of the huge volumes of carbon dioxide that would be released by the combustion or gasification of the large quantities of coal that would be used in any clean coal scenario. Nevertheless, a possible primary energy mix for such a strategy is shown in Figure 10.4, using the same energy demand assumptions as in Figure 10.3. In this scenario we have also assumed that both
nuclear power and renewable energy would still play a significant role in the primary energy mix, but with much smaller annual growth rates compared with the previous scenario.
We have also made the same assumptions about the declining availability of crude oil and natural gas as in the renewable energy and nuclear power scenario. The share of total primary energy supply provided by coal under this new scenario has then been assumed to increase in every decade, reaching 50% of total primary energy supply by the end of the century compared with 23% in 2000. Of course, the actual mix of primary energy sources that will
develop over the remainder of this century is likely to be somewhere between these two scenarios. The primary energy supply mix that evolves over time will depend on both advances in technology and on the priority which individuals and governments give to developing cleaner and more sustainable energy sources.
In this book Evans has focused primarily on technological solutions to developing a more sustainable energy supply, but we should not forget that one of the most important options open to mankind is to simply reduce our demand for energy in the first place. This is sometimes referred to as the ‘‘soft-side’’ of energy policy, but programs aimed at convincing corporations, governments, and individuals to use energy more efficiently, and to simply avoid wasteful or frivolous use, will be powerful tools in the quest for a more sustainable economy. Success with these types of programs, whether they are primarily aimed at ‘‘energy conservation’’ on the part of individual users, or more sophisticated ‘‘demand-side management’’ policies for large corporations and utilities, requires widespread behavior modification.
Policymakers need to be aware, therefore, that the development of sustainable energy policies needs the wholehearted participation not only of scientists,
engineers, and economists, but also of social-scientists and the general public at large if they are to be successful. What appears quite clear, however, is that there are viable solutions to the quest for cleaner energy supplies which should be sufficient to provide all of our requirements for the foreseeable future.
It’s now up to all of us: corporate leaders, politicians, and individual consumers, to play our part in seeing that our energy future is a truly sustainable one.
[Seems that the issues have become even more complicated in 2021 than were the case in 2007 ....?]
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