A broad-brush story of energy

SWADESH MAHAJAN

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THE spectre of global warming, perhaps the most profound crisis that mankind is heir to, relentlessly forces us to understand and evaluate ‘Energy’ so that we may develop a sensible defence strategy against an impending disaster. The book Naturally: Tread Softly on the Planet, looks at the energy issue from two points of view. First, that the fallout should be non-invasive to the planet and for that we must factor in the apparatus (for example, lead or lithium batteries for storing solar energy) which can lead to waste that may not be recyclable/renewable. As clearly articulated, at present no energy option is completely renewable – including those based on renewable sources. This is an ideal final solution and we can expect only long-term progress. Second, that each energy should be evaluated by its efficiency of conversion and distribution, where progress can be faster. The author of the book reviews many energy solutions.

I am neither a policy advisor nor an advocate of this or that form of energy, although I am a physicist and an inventor who has long worked to devise systems that would make nuclear energy safe, relatively green and plentiful and with minimum waste. I would, however, like to tell a story – a story about, and of energy. Such stories, regretfully, do not constitute a necessary part of our growing up – even the so-called ‘educated’ class is just as deprived as the less privileged.

The context could not be clearer; we are constantly bombarded with a myriad, often conflicting, messages from energy experts and pundits and advocates and critics. There is a broad consensus among the scientifically informed that the earth is warming at an ‘unnaturally’ rapid rate – the greenhouse gases (in particular, carbon dioxide or CO2), an ineluctable consequence of man’s addiction to energy consumption, being the primary reason. In this note, anthropogenic global warming will be given the status of an observational/modelling/inferential verity. I shall waste no time on taking on the climate change doubters and deniers, even the rational sounding skeptics.

To avert the looming global crisis, both the quantity as well as the composition of our energy consumption must change, drastically. And we are a very non-homogeneous entity to boot. There are the rich countries of the West, historically the principal consumers, and there are economically emerging nations, just discovering the good life made accessible via unchecked energy consumption, not to speak of the relatively poorer societies who can only dream of emulating the other. The task of creating and enforcing a new enlightened global energy policy that may be acceptable to all (even though it may not be equitable), is more than formidable. I will, therefore, be patient while examining the hundreds of notes, some very discordant, that are struck in the ongoing energy debate. The final aim, of course, is to propose some guiding principles for a sensible, doable strategy.

 

The energy controversy spans highly animated discussions on fossils versus renewables, nuclear versus fossils, nuclear versus renewables like the Hobbesian war of all against all. We hear a plenty of judgments: (i) renewables: good, fossils: bad, nuclear: bad. (ii) fossils not so bad, nuclear worse. (iii) fossils awful, nuclear not so bad, (iv) fossils and nuclear are both fine – get off our back you tree huggers.

There is an endless debate on what we should do on the energy front. Fundamentally, such debates are very healthy, exactly what a responsible and democratic people should engage in. One must, however, remember that when wishful/partisan thinking and strident advocacy replace scientific soundness, confusion reigns and truth becomes a casualty.

We begin our story by taking stock of the energy bounty of Mother Earth. In a common idiom, one could identify four categories:

1. Current income: incident sunlight is the source of all renewables – plants (animals), windmills, solar cells/thermal – all with different but short time scales.

2. Savings account in the form of past sunlight: All fossils – coal, oil, and natural gas. Fossils are the end products of highly complex processing by Mother Earth. The renewal periods ~10-100 million years are very large compared to the human life scale. It is sensible to class fossils as non-renewable.

3. The current and savings account are backed up by a huge inheritance that the earth was born with. It is convenient to place the earth’s ancestral gifts in two distinct boxes: Patrimony 1 in the form of elements uranium and thorium that via nuclear fission can and does produce what we call nuclear energy. These very heavy elements were generated in extreme conditions in super novae, and were a part of the cosmic dust from which our solar system was formed. This is a huge endowment.

 

Patrimony 2 consists of enormous amounts of deuterium, a kind of heavy hydrogen, available in sea water. This is a gift from the very early eras of the universe, and its energy content that can be tapped through nuclear fusion is just utterly enormous. Both these patrimonies, generous as they may be, are, by definition, non-renewable.

The reader may or may not have noted that directly or indirectly, the source of all our energy options, including the geothermal and renewables, is nuclear energy. The sun whose glory we bask in, manufactures its energy from nuclear fusion. A similar narrative is also to be found in the book, ‘Naturally’.

What have we done with this sumptuous energy bounty? For much of its history, mankind has subsisted on current income. We literally woke up with the sun, and went to bed with the sunset.

The industrial revolution, however, was fuelled by the savings account; it was driven by the concentrated energy in the fossils, the current income was not enough. It was quite a revolution on the physical as well as psychological fronts. We produced a lot more food, grew in numbers, increased our appetite further, and spent the savings at a reckless pace. Much of the earth’s vast storehouse of energy, processed and accumulated over 100 million years, was spent in a few centuries, the twentieth being the most profligate one. While we (more correctly, some of us) were on a spending spree, it was hard to imagine that this indulgence could come back to haunt us, though alarm bells had started sounding 50-60 years ago.

 

The dawn of the atomic age ushered in an era of drawing from Patrimony 1. There was a belief (even among the cognoscenti) that the nuclear fission energy will be ‘totally’ safe and so cheap that there will be no need to meter it. Neither of these euphoric claims, made in the infancy of the nuclear age, has withstood the ravages of time. Nuclear energy has, however, contributed significantly to the energy budget – about 16% of world electricity (~6% of the total energy).

It was in the middle of the twentieth century that scientists started exploring the possibility of dipping into Patrimony 2. The so-called controlled thermonuclear fusion programme to harness the virtually inexhaustible energy locked up in heavy water has made tremendous strides but it is far from providing us net energy as fission and fossils do. Fusion is not likely to be a partner feeding the energy grid for a long time to come.

It may be of interest to note that although fusion is not ready to be a direct source of net energy, it can play a very important role in the energy economy by assisting fission to help solve two of its most telling problems: nuclear waste, and an eventual shortage of fissionable material. A creative and synergistic combination of the two sister nuclear channels, the fusion and the fission, can support a relatively green, safe, and long lasting nuclear economy, and can begin to replace fossils in time scales relevant to our fight against global warning.

Despite this somewhat optimistic note on nuclear energy, one must grapple with a basic question: Why is it that we have been in such desperate haste to dip deeper into the earths’ savings and patrimony? Why, for instance, did we embark on a nuclear programme three generations ago, when coal and oil were king and no one had quite appreciated the impending environmental catastrophe?

It is quite amazing that this seemingly impossible question has a rational, clear and definite answer: it is the very high energy density of fossils compared to that of renewables, for instance, that mankind finds so attractive. The energy density in the nuclear material is around a hundred thousand-million times higher than of fossils. One ton of deuterium has the same available energy content as three million tons of coal!

 

Since this is a crucial issue to understand in the story of energy, I will repeat, in a somewhat different manner, the content of the preceding paragraphs: first, sunlight is good, in fact, ideal, but it is much less energy-dense as the processed and stored sunlight in fossils; second, fossil energy density, in turn, is minuscule compared to that of nuclear patrimony – nuclear energy reactions are a hundred million time more energetic than the chemical reactions powering fossils. The lure of nuclear energy will always be as great as the lure of fossil energy was over the last few hundred years. Perhaps, the most important message to carry home is that irrespective of whether they have low or high energy density, no energy source is intrinsically evil.

After this introduction, I proceed to express my own thoughts and views as a short enquiry into the grand energy debate: renewables and the fossil crisis, and the nuclear dilemma – what is to be done? It does not require much courage or foresight to assert that the first, second, and third laws of planetary/human welfare are exactly the same: if one can live on one’s current income, one must do so. In this context, inheritance and savings are best used to start new ventures and deal with emergencies. A little indulgence here and there will not hurt! But do we have the wisdom and maturity to do so? Even more critically, can we maintain an effective level of life/style for the vast population with such constraints. Our civilization is practically fossil sustained, and continued fossil use is predicted, beyond reasonable doubt, to be perilous. So we cannot live with fossils but how do we learn to live well without fossils.

 

Devising an appropriate strategy is challenging per se; it becomes even more challenging because the energy debate is not always dictated by the best science/technology. Entrenched short-term economic interests, emotions, and wishful thinking often dominate the discourse. In the prevailing energy debate, we often encounter strident ‘advocacy’ trumping a relentless search for the most knowable truth. The renewable advocates (well motivated folks, in general), often allow wishful thinking to overpower established scientific opinion. Fossils and nuclear emerge as ‘evil’ incarnate in their standard narratives. Fossil and nuclear advocates, on the other hand, incessantly undermine the problems associated with and created by their widespread use. They further insist that renewables cannot meet our demands on any near term frame of time.

What is also unfortunate but fascinating is that the huge energy density of nuclear energy excites primitive irrational fears and creates mind-blocks against an honest discourse.

One should remember that fossils were and remain a great and attractive source of concentrated energy. Although the hazards arising from their cumulative use does dictate phasing them out at the fastest rate possible, some fantastic technical advance could make them attractive again. I will, however, not bet my retirement on that chance.

 

I believe that the optimum energy scenario for the next 25-50 years is to harness nuclear energy (in its most advanced version) to replace fossils at the highest possible rate while renewables build up their capacity, in particular, the base-load capacity. Here is a somewhat prosaic prescription (with some flourishes) to damp the global fever. Make as much renewables as is compatible with science, and other constraints. The movement is already on. Exploit the awesome potential of nuclear energy – vast magnitudes are locked up in a small amount of material. It should be very attractive as long as it can be made safe, and environmentally acceptable. And because of the real as well as perceived dread of a nuclear accident, the society must ensure and enforce extremely strict and demanding safety standards.

There are not, and there will not be perfect energy sources. All are flawed (some more than others), especially when exploited in bulk over long period of time with lax controls.

The imperative, then, is to find a realistic and scientifically warranted energy mix; this mix, of course, will be a function of time. Enlightened policy, coupled with market forces, is likely to be the determinant. It will not be prudent, however, to wait for the perfect solution while the earth suffocates on CO2.

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