Category: Fuel Cell

New Book: ‘Water, Energy, and Environment – A Primer’

After a long hiatus from blogging while I worked on a new book, I am pleased to announce that the book ‘Water, Energy, and Environment – A Primer’ will be published by International Water Association Publishing (IWAP) on February 18th (2019). It will be available in both printed and digital form, and the digital version will be downloadable for free as an Open Access (OA) document.

To access the free digital version go to IWAP’s OA website on Twitter: https://twitter.com/IWAP_OA.

Attached below is front material from the book, its preface and table of contents. Designed to serve as a basic and easily read introduction to the linked topics of water, energy, and environment, it is just under 200 pages in length, a convenient size to throw into a folder, a briefcase, or a backpack. Its availability as an OA document means that people all over the world with access to the internet will have access to the book and its 10 chapters.

With the completion of the book I plan to return to a regular schedule of blogging.
…………………………..
Contents
Preface ………………………………….. xi
Acknowledgement ……………………….. xv
Acronyms ……………………………… xvii
Epigraph ……………………………….. xxi
Chapter 1
Water and its global context …………………. 1
1.1 Earth’s Water Resources . . . . . . . . . . . . . . . . . . . . . . . . . . 1
1.2 Saline Water and Desalination Processes . . . . . . . . . . . 2
1.3 Energy Requirements and Costs of Desalination . . . . . 5
1.4 Demand for Freshwater . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
1.5 Implications of Limited Access to Freshwater . . . . . . . . . 9
1.6 Actions to Increase Access to Freshwater . . . . . . . . . . 10
1.7 Gender Equity Issues . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Chapter 2
Energy and its global context ……………….. 13
2.1 Energy’s Role in Society . . . . . . . . . . . . . . . . . . . . . . . . . 13
2.2 Energy Realities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
2.3 What is Energy? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
2.4 Energy Trends . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
2.4.1 Important questions . . . . . . . . . . . . . . . . . . . . . . . 18
2.4.2 How is energy used? . . . . . . . . . . . . . . . . . . . . . . 18
2.4.3 Electrification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
Chapter 3
Exploring the linkage between water
and energy ……………………………….. 23
3.1 Indirect Linkages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
3.2 The Policy Linkage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
3.3 The Conundrum . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
3.4 Addressing the Conundrum . . . . . . . . . . . . . . . . . . . . . . . 26
3.5 The Need for Partnership . . . . . . . . . . . . . . . . . . . . . . . . . 27
Chapter 4
Energy production and its consequences for
water and the environment …………………. 29
4.1 Impacts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
4.2 More on Climate Change . . . . . . . . . . . . . . . . . . . . . . . . . 32
4.3 Environment and Religion . . . . . . . . . . . . . . . . . . . . . . . . 33
4.3.1 The theocentric worldview . . . . . . . . . . . . . . . . . 33
4.3.2 The anthropocentric worldview . . . . . . . . . . . . . 34
4.3.3 Other worldviews . . . . . . . . . . . . . . . . . . . . . . . . . 34
Chapter 5
Energy options ……………………………. 37
5.1 Fossil Fuels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
5.2 Nuclear Energy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
5.3 Geothermal Energy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
5.4 The Sun . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
5.5 Energy Efficiency . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
5.5.1 Energy demand . . . . . . . . . . . . . . . . . . . . . . . . . . 40
vi Water, Energy, and Environment – A Primer
5.5.2 Implementation . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
5.5.3 Saving energy . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
5.5.4 Accelerating implementation . . . . . . . . . . . . . . . 43
5.5.5 Energy Star . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44
5.5.6 The lighting revolution . . . . . . . . . . . . . . . . . . . . . 45
5.5.7 Energy efficiency in buildings . . . . . . . . . . . . . . . 48
5.5.7.1 Zero energy buildings . . . . . . . . . . . . . 48
5.5.7.2 Electrochromic windows . . . . . . . . . . . 52
5.6 Energy Efficiency in Industry . . . . . . . . . . . . . . . . . . . . . . 54
5.7 Energy Efficiency in Transportation . . . . . . . . . . . . . . . . 56
Chapter 6
Fossil fuels ………………………………. 61
6.1 Coal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62
6.1.1 Carbon capture and sequestration . . . . . . . . . . 63
6.1.2 A conundrum . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65
6.2 Petroleum . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68
6.2.1 Oil spills . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68
6.2.2 Peak oil . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72
6.3 Natural Gas . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76
6.3.1 Methane hydrates . . . . . . . . . . . . . . . . . . . . . . . . . 77
6.3.2 Fracking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 80
Chapter 7
Nuclear power ……………………………. 85
7.1 Nuclear Fission . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85
7.1.1 Fission fundamentals . . . . . . . . . . . . . . . . . . . . . . 85
7.1.2 Introduction to nuclear issues . . . . . . . . . . . . . . . 87
7.1.3 Issues . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89
7.2 Nuclear Fusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91
7.2.1 Fusion fundamentals . . . . . . . . . . . . . . . . . . . . . . 91
7.2.2 Numbers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 93
7.2.3 Barriers to Fusion . . . . . . . . . . . . . . . . . . . . . . . . . 94
7.2.4 Pros and cons . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95
7.2.5 Thoughts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95
Chapter 8
Renewable energy ………………………… 97
8.1 The Sun’s Energy Source and Radiation
Spectrum . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 98
8.2 Direct Solar Energy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 102
8.2.1 Photovoltaics . . . . . . . . . . . . . . . . . . . . . . . . . . . . 102
8.2.2 Concentrating solar power (CSP) . . . . . . . . . . 108
8.2.2.1 Power tower . . . . . . . . . . . . . . . . . . . . 109
8.2.2.2 Linear concentrator . . . . . . . . . . . . . . 110
8.2.2.3 Dish engine . . . . . . . . . . . . . . . . . . . . . 111
8.2.2.4 CSTP history . . . . . . . . . . . . . . . . . . . 112
8.2.2.5 Advantages and disadvantages . . . 112
8.2.2.6 Thermal storage . . . . . . . . . . . . . . . . . 113
8.2.2.7 Current status . . . . . . . . . . . . . . . . . . . 114
8.2.2.8 Concentrating photovoltaics (CPV) . 115
8.3 Solar Power Satellite (SPS) System . . . . . . . . . . . . . . 116
8.4 Hydropower and Wind Energy . . . . . . . . . . . . . . . . . . . 119
8.4.1 Hydropower . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 119
8.4.2 Wind energy . . . . . . . . . . . . . . . . . . . . . . . . . . . . 121
8.4.2.1 Onshore wind . . . . . . . . . . . . . . . . . . . 121
8.4.2.2 History . . . . . . . . . . . . . . . . . . . . . . . . . 124
8.4.2.3 An onshore limitation . . . . . . . . . . . . . 124
8.4.2.4 Offshore wind . . . . . . . . . . . . . . . . . . . 125
8.5 Biomass Energy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 129
8.5.1 Sources of biomass . . . . . . . . . . . . . . . . . . . . . . 129
8.5.2 Wood . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 129
8.5.3 Biofuels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 130
8.5.4 Algae . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 131
8.5.5 Biochar . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 132
8.5.6 The future . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 132
8.6 Geothermal Energy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 134
8.6.1 Sources of geothermal energy . . . . . . . . . . . . . 134
8.6.2 Manifestations of geothermal energy . . . . . . . 135
8.6.3 Uses of geothermal energy . . . . . . . . . . . . . . . . 135
8.6.3.1 Geothermal power generation . . . . . 136
8.6.3.2 Ground-source heat pumps . . . . . . . 138
8.6.4 An unusual source of geothermal energy . . . . 140
Ocean Energy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 142
8.7.1 Wave energy . . . . . . . . . . . . . . . . . . . . . . . . . . . . 142
8.7.1.1 Wave energy conversion
devices . . . . . . . . . . . . . . . . . . . . . . . . 142
8.7.1.2 Potential and pros and cons . . . . . . . 143
8.7.2 Ocean current energy . . . . . . . . . . . . . . . . . . . . 144
8.7.3 Tidal energy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 146
8.7.3.1 Barrage . . . . . . . . . . . . . . . . . . . . . . . . 146
8.7.3.2 History . . . . . . . . . . . . . . . . . . . . . . . . . 147
8.7.3.3 Environmental impacts . . . . . . . . . . . 147
8.7.4 Ocean thermal energy conversion (OTEC) . . 147
8.7.4.1 Barriers . . . . . . . . . . . . . . . . . . . . . . . . 148
8.7.4.2 OTEC technologies . . . . . . . . . . . . . . 148
8.7.4.3 Other cold water applications . . . . . . 149
8.7.4.4 OTEC R&D . . . . . . . . . . . . . . . . . . . . . 149
Chapter 9
Energy storage …………………………… 151
9.1 Storage and Grids . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 151
9.2 Types of Storage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 152
9.2.1 Traditional and advanced batteries . . . . . . . . . 153
9.2.1.1 Lead–acid . . . . . . . . . . . . . . . . . . . . . . 153
9.2.1.2 Sodium sulfur . . . . . . . . . . . . . . . . . . . 153
9.2.1.3 Nickel–cadmium . . . . . . . . . . . . . . . . . 154
9.2.1.4 Lithium-ion . . . . . . . . . . . . . . . . . . . . . 154
9.2.1.5 Supercapacitors . . . . . . . . . . . . . . . . . 155
9.2.2 Flow batteries . . . . . . . . . . . . . . . . . . . . . . . . . . . 156
9.2.3 Flywheels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 157
9.2.4 Superconducting magnetic energy
storage (SMES) . . . . . . . . . . . . . . . . . . . . . . . . . 158
9.2.5 Compressed air energy storage (CAES) . . . . 159
9.2.6 Pumped storage . . . . . . . . . . . . . . . . . . . . . . . . . 160
9.2.7 Thermal storage . . . . . . . . . . . . . . . . . . . . . . . . . 161
9.3 Applications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 161
9.4 Costs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 162
9.5 Fundamental Change . . . . . . . . . . . . . . . . . . . . . . . . . . . 163
Chapter 10
Policy considerations …………………….. 165
10.1 Important Questions . . . . . . . . . . . . . . . . . . . . . . . . . . . 166
10.1.1 Is there a physical basis for understanding
global warming and climate change? . . . . . . 166
10.1.2 Is there documented evidence for global
warming and climate change? . . . . . . . . . . . . 168
10.1.3 Can global warming and climate change be
attributed to human activities, and what are
those activities? . . . . . . . . . . . . . . . . . . . . . . . . 170
10.1.4 What are the potential short- and long-term
impacts of global warming and climate
change with respect to water supply,
environment, and health? What is the
anticipated time scale for these
impacts? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 172
10.1.5 What can be done to mitigate the onset
and potential impacts of global warming
and climate change? . . . . . . . . . . . . . . . . . . . . 179
References ……………………………… 183
Index …………………………………… 189

……………………

Preface
This book springs from my strong conviction that clean water and clean energy are the critical elements of long-term global sustainable development. I also believe that we are experiencing the beginning of an energy revolution in these early years of the 21st century. Providing clean water requires energy, and providing clean energy is essential to reducing the environmental impacts of energy production and use. Thus, I see a nexus – a connection, a causal link – among water, energy, and environment. In recent years we have adopted the terminology of the water-energy nexus for the intimate relationship between water and energy, and similarly we can apply the term nexus to the close connections among water, energy, and environment. Thisuse of the term nexus can be, and has been, extended to include the related issues of food production and health. Dealing with, and writing about, a two-element nexus is difficult enough. In this book, I will limit my analysis and discussion to the three-element water -energy-environment nexus and leave the discussion of other possible nexus elements to those more qualified to comment.

This book also springs from my observation that while there are many existing books of a more-or-less technical nature on the three elements of this nexus, a book addressing each of them and their interdependencies in a college-level primer for a broad global and multidisciplinary audience would be valuable. Consideration of these and related issues, and options for addressing them, will be priorities for all levels of government. They will also be priorities for many levels of the
private sector in the decades ahead, both in developing and developed nations. A handbook-style primer that provides an easily read and informative introduction to, and overview of, these issues will contribute broadly to public education. It will assist governments and firms in carrying out their responsibilities to provide needed services and goods in a sustainable manner, and help to encourage young people to enter these fields. It will serve as an excellent mechanism for exposure of experts in other fields to the issues associated with the water-energy-environment nexus. Further, in addition to the audiences mentioned above, target audiences include economists and others in the finance communities who will analyze and provide the needed investment funds, and those in the development community responsible for planning and delivering services to underserved populations.
The book is organized as follows: the first chapter will be devoted to the concept of nexus and how the three elements, water, energy, and environment, are inextricably linked. This recognition leads to the conclusion that if society is to optimize their contributions to human and planetary welfare they must be addressed jointly. No longer must policy for each of these elements be considered in its own silo. Chapters 2 and 3 will be devoted to spelling out global contexts for water and energy issues, respectively. Chapter 4, on related environmental issues, will address the issues of water contamination, oil spills, fracking, radioactive waste storage, and global warming/
climate change. Chapter 5 will be a discussion of energy efficiency – i.e., the wise use of energy – and its role in limiting energy demand and its associated benefits. Chapter 6 will focus on the basics of fossil fuels – coal, oil, natural gas – which today dominate global energy demand. Chapter 7 will discuss nuclear-fission-powered electricity production, which today accounts for 10% of global electricity. It will also discuss the prospects for controlled nuclear fusion. Chapter 8 will discuss the broad range of renewable energy technologies – wind, solar,hydropower, biomass, geothermal, ocean energy – which are the basis of the now rapidly emerging energy revolution. Chapter 9 will discuss the closely related issue of energy storage. Finally, Chapter 10 will address
policy issues associated with water, energy, and environment, discuss policy history and options, and provide recommendations.

Looking Ahead 30-40 Years – A Risky Business

History has always been my favorite subject, starting in high school, and still constitutes a major part of my personal reading. Needless to say I have a strong interest in other topics as well, as attested to by my long career in science and engineering and education/mentoring activities with young people. What often fascinates me is looking back at how things have changed in the past, often in unexpected ways, and how people looking back in the decades ahead will put their perspectives on what we are doing today. This blog post is my attempt to flesh out these thoughts, while acknowledging the difficulty of looking into the future. If I look far enough into that future I will not be around to suffer the slings and arrows of projecting incorrectly, or collecting the kudos for projecting accurately. Nevertheless, it feels like a stimulating and challenging activity to undertake, and so here goes.

image

Let me start by going back seven decades to the 1940s when I was a young kid growing up in the Bronx and just beginning to form my likes and dislikes and develop opinions. My love for science fiction developed at that time and was probably a dead give-away of my future career interests. An important shaping event was the dropping of the first atomic bomb on Japan on August 6, 1945, an event that I still clearly remember learning about on the radio while sitting in the back seat of my parents’ car. Without a deep or much of any understanding at that time, I somehow sensed that the world had changed in that August moment. I still feel that way after many subsequent years of reading and studying.

The following decades saw several other unexpected and defining events: the addition of fusion weapons (hydrogen bombs) to our nuclear arsenals, commercial applications of controlled nuclear fission (nuclear submarines and nuclear-powered surface ships, and the first commercial nuclear power plant which was actually a land-based nuclear submarine power plant), development and emergence of the transistor as a replacement for vacuum tubes (first using germanium and then silicon), the development of the first solar cell at Bell Labs, the development and application of laser technology, the emergence of the information technology industry based on the heretofore abstract concepts of Boolean algebra (0s and 1s), and the increasing attention to a wide range of clean energy technologies that had previously been considered impractical for wide scale application – wind, solar, geothermal, ocean energy, fuel cells, advanced battery technologies, and a broad range of alternative liquid and gaseous fuels. Each in its own way has already changed and will further change the world in future decades, as will other technologies that we now only speculate about or cannot imagine. This is the lesson of history – it is difficult for most of us to look ahead and successfully imagine the future, and one of my earlier blog posts (‘Anticipating the Future: It Can Be Difficult’) discusses this topic. In the following paragraphs I speculate about the future with humility but also great anticipation. My only regret is that I will not live long enough to see most of this future unfold.

I will divide this discussion into two parts on which I have focused some attention and feel that I have some knowledge – medicine/health care, and energy. That leaves all too many aspects of the future that I don’t feel qualified to comment upon – e.g., what more will we learn about Amelia Earhart’s disappearance, Cuba’s possible participation in John Kennedy’s assassination, and the future of the tumultuous Middle East and the countries of the former Soviet Union. My primary focus in this post will be on the latter of the two parts, energy.

To help you understand my interest in medicine and health care I confess that at one point in my career, before committing to pursuing a PhD in physics, I gave serious consideration to attending medical school. During this period in the early 1960s I was a research scientist at Texas Instruments (TI) and was excited about the possibilities of miniature electronics which TI was pioneering in. I even suggested to my TI bosses that we undertake the application of transistors and sensors to artificial vision, but it was much too early for the company to make such a commitment. Today, 50 years later, that vision is being realized.

I also see great promise in the application of miniature electronics to continuous in-vivo diagnosis of human health via capsules that float throughout a human’s blood network, monitor various chemical components, and broadcast the results to external receivers. This will depend on low-powered miniature sensors and analysis/broadcast capability powered by long-lasting miniature batteries or an electrical system powered by the human body itself. Early versions are now being developed and I see no long-term barriers to developing such a system.

A third area in which I see great promise is the non-invasive monitoring of brain activity. This is a research area that I see opening up in the 21st century as we are beginning to have the sensitive tools necessary to explore the brain in detail. Given that the brain is responsible for so many aspects of our mental and physical health I expect great strides in the coming decades in using brain monitoring to address these issues.

The energy area is where I have devoted the bulk of my professional career and where my credibility may be highest – at least I’d like to think so. Previous blog posts address my thoughts on a wide range of current energy, water-energy, and related policy issues. Recognizing that changes in our energy systems come slowly over decades and sometimes unexpectedly, as history tells us, I will share my current thoughts on where I anticipate we will be in 30-40 years.

Let me start with renewable energy – i.e., solar, wind, hydropower, geothermal, biomass, and ocean energy. I have commented on each of these previously, but not from a 30-40 year perspective. Renewables are not new but, except for hydropower, their entering or beginning to enter the energy mainstream is a relatively recent phenomenon. Solar in the form of photovoltaics (PV) is a truly transformative technology and today is the fastest growing energy source in the world, even more so than wind. This is due to significant cost reductions for solar panels in recent years, PV’s suitability for distributed generation, its ease and quickness of installation, and its easy scalability. As soon as PV balance-of-system costs (labor, support structures, permitting, wiring) come down from current levels and approach PV cell costs of about $0.5-0.7 per peak watt I expect this technology to be widespread on all continents and in all developed and developing countries. Germany, not a very sunny country but the country with the most PV installed to date, has even had occasional summer days when half its electricity was supplied by solar. In combination with energy storage to address its variability, I see PV powering a major revolution in the electric utility sector as utilities recognize that their current business models are becoming outdated. This is already happening in Germany where electric utilities are now moving rapidly into the solar business. In terms of the future, I would not be surprised if solar PV is built into all new residential and commercial buildings within a few decades, backed up by battery or flywheel storage (or even hydrogen for use in fuel cells as the ultimate storage medium). Most buildings will still be connected to the grid as a backup, but a significant fraction of domestic electricity (30-40%) could be solar-derived by 2050. The viability of this projection is supported by the NREL June 2012 study entitled ‘Renewable Electricity Futures Study’.

Hydropower already contributes about 10% of U.S. electricity and I anticipate will grow somewhat in future decades as more low-head hydro sites are developed.

For many years onshore wind was the fastest growing renewable electricity source until overtaken recently by PV. It is still growing rapidly and will be enhanced by offshore wind which currently is growing slowly. However, I expect offshore wind to grow rapidly as we approach mid-century as costs are reduced for two primary reasons: it taps into an incredibly large energy resource off the coasts of many countries, and it is in close proximity to coastal cities where much of the world’s population is increasingly concentrated. In my opinion, wind, together with solar and hydro, will contribute 50-60% of U.S. electricity in 2050.

Other renewable electric technologies will contribute as well, but in smaller amounts. Hot dry rock geothermal wells (now called enhanced geothermal systems) will compete with and perhaps come to dominate traditional geothermal generation, but this will take time. Wave and tidal energy will be developed and become more cost effective in specific geographical locations, with the potential to contribute more in the latter part of the century. This is especially true of wave energy which taps into a large and nearly continuous energy source.

Biomass in the form of wood is an old renewable energy source, but in modern times biomass gasification and conversion to alternative liquid fuels is opening up new vistas for widescale use of biomass as costs come down. By mid-century I expect electrification and biomass-based fuels to replace our current heavy dependence on petroleum-based fuels for transportation. This trend is already underway and may be nearly complete in the U.S. by 2050. Biomass-based chemical feedstocks will also be widely used, signifying the beginning of the end of the petroleum era.

I expect that other fossil fuels, coal and natural gas, will still be used widely in the next few decades, given large global resources. Natural gas, as a cleaner burning fossil fuel, and with the availability of large amounts via fracking, will gradually replace coal in power plants and could represent 30-40% of U.S. power generation by mid-century with coal generation disappearing.

To this point I have not discussed nuclear power, which today provides close to 20% of U.S. electricity. While I believe that safe nuclear power plants can be built today –i.e., no meltdowns – cost, permanent waste storage, and weapons proliferation concerns are all slowing nuclear’s progress in the U.S. Given the availability of relatively low-cost natural gas for at least several decades (I believe fracking will be with us for a while), the anticipated rapid growth of renewable electricity, and the risks of nuclear power, I see limited enthusiasm for its growth in the decades ahead. In fact I would not be surprised to see nuclear power supplying only about 10% of U.S. electricity by 2050, and less in the future.

To summarize, my picture today of an increased amount of U.S. electricity generation in 2050 is as follows:

Generating Technology : Percent of U.S. Generation in 2050
nuclear: 5-10
coal: 0-5
Oil: 0
natural gas: 30-40
solar + wind + hydro: 50-60
other renewables: 5-10

I am sure that some readers of this post will take strong issue with my projections and have very different thoughts about the future. I welcome their thoughts and invite them to join me in looking ahead. As the title of this post acknowledges, looking ahead is risky business, but it is something I’ve wanted to do for a while. This seems as good a time as any to do so.

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Hydrogen and Fuel Cells: Important Parts of Our Energy Future?

Hydrogen is a simple atom/molecule and the most abundant element in the universe.

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As a physicist it is an an article of faith with me that mankind will eventually make large scale use of hydrogen as a fuel. As a realistic physicist I also acknowledge that such large scale use of hydrogen is a number of years away.

The device that will convert hydrogen into a major energy source is the fuel cell, which is an electrochemical device that combines hydrogen and oxygen to produce electricity, with water and heat as its by-product. First invented in the 19th century, today there is extensive research and a large and growing literature on fuel cells.

In its simplest form, a fuel cell consists of two electrodes – an anode and a cathode – with an electrolyte between them.

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When cells are stacked in series the output increases, resulting in fuel cells with power capacities ranging from several watts to several megawatts. A fuel cell system that includes a fuel reformer can obtain hydrogen from any hydrocarbon fuel such as natural gas, methanol, or gasoline. Since fuel cells rely on an electrochemical process and not combustion, emissions from fuel cells are significantly lower than emissions from even the cleanest fuel combustion processes. Fuel cells are also quiet, durable, and highly efficient. They are different from batteries in that they require a constant source of fuel and oxygen/air to sustain the chemical reaction; however, fuel cells can produce electricity continually for as long as these inputs are supplied.

My enthusiasm for hydrogen goes beyond my physics daydreaming: I often refer to it as the ultimate energy storage system. For example, what does a utility do with excess electricity generated by wind turbines at night when the wind is often strongest and consumer demand for electricity is lowest. The simple answer is to store it for delivery during the next day when demand and electricity prices are higher. Of course, storage is not energy- or cost-free, and still expensive today. My attraction to hydrogen is that excess electricity can be used to electrolyze a common substance (water) into hydrogen and oxygen and the hydrogen can be stored and used in fuel cells which transmit their generated electricity to consumers in many locations via power lines. No need to transport hydrogen via pipelines which are inherently expensive and often hard to site, and these pipelines have to be impervious to leakage by the tiny hydrogen molecule, unlike more standard fossil fuel pipelines. The kickers in this game are that water has to be available and the efficiency of electrolysis devices needs to be improved to reduce the cost of hydrogen production.

A fuel cell is a transformative technology that changes the way we generate and use electricity, a characteristic it shares with solar PV. It can be used in small and large sizes, in mobile and stationary applications, and has several technological foundations (proton exchange membrane, phosphoric acid, solid oxide). The hitch in fuel cells is cost reduction, a tough problem to address, and they’re competing as storage devices with lithium ion batteries which are steadily getting cheaper. Flywheels, when mass produced, may also offer some competition.

I’ve been following fuel cell development issues for almost forty years, since arriving in Washington, DC, and cost seems to be the major barrier to their large-scale use. Lots of effort is going into related research, including how to mass produce cheaply. The U.S. Department of Energy is supporting this effort both for mobile applications (i.e., cars) and larger stationary applications.

Considerable effort is also going into development of micro fuel cells that can be used to power cell phones, laptop computers and tablets – all of which can benefit from longer-lasting portable power supplies. These will probably be fueled by replaceable alcohol-water cartridges where the alcohol (ethanol/C2H5OH or methanol/CH3OH) supplies the needed hydrogen. For example, one mixture under investigation is 35% methanol in water. Such a micro fuel cell could provide ten hours of laptop time, although some computer tablets today achieve that goal. The reason for not going above 35% is that methanol interacts chemically with common anode and cathode materials and degrades the fuel cell. Nanotechnology may offer new material options, allowing this percentage to increase. An interesting aspect of alcohol use in micro fuel cells is that alcohol, being flammable, requires a waiver to be brought onto airplanes. Ethanol clearly has such a waiver as witnessed by drink service on most aircraft. Methanol only recently obtained such a waiver.

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