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How viable is renewable energy?


Both solar and wind energy depend on rare earth elements that will likely become scarce in 20 years or so. China accounted for 95 percent of the world’s rare-earth production, raising fears that it might exert monopolistic control. Meanwhile, renewable energy technologies that could function without rare earths, particularly photovoltaic technologies, aren’t close to deployment.

Clear path, indecisive travelers

Sagar Dhara, Bulletin of Atomic Scientists

Humans have often convinced themselves that technology will save them from disaster. They’ve indulged in the cornucopian myth of an Earth whose resources are limitless. Some societies—the Mayans, for example—have suffered outright collapses when their technologies failed, or when energy or other material resources ran scarce. Human beings will face a similar predicament in the not-so-distant future if they place too much faith in technological approaches to climate change and not enough emphasis on necessary political and philosophical shifts. But excessive faith in technology is what my roundtable colleagues Jennie Stephens, Elizabeth Wilson, and Saleemul Huq displayed In Round One regarding wind power and rooftop photovoltaic technology.

In my first essay, I discussed several factors that constrain photovoltaic and wind technologies—their intermittency, their land requirements, and so forth. I lacked space to mention a few additional constraints. Both solar and wind energy depend on rare earth elements that will likely become scarce in 20 years or so. As recently as five years ago, China accounted for 95 percent of the world’s rare-earth production, raising fears that it might exert monopolistic control. China’s share of production has since dropped, but China still has the world’s largest reserves of rare earths by far, and worries about monopolistic behavior persist. Meanwhile, renewable energy technologies that could function without rare earths, particularly photovoltaic technologies, are not close to commercial deployment.

And as I mentioned only in passing in Round One, the manufacture of photovoltaic panels entails carbon dioxide emissions. In fact, analyses of the life cycle of photovoltaics indicate that if manufacturing grows at an annual rate exceeding the inverse of the panels’ carbon dioxide “payback” time, photovoltaics will account for more emissions in their manufacture than will be saved through their use. To illustrate, the average carbon dioxide “payback” period for photovoltaics is now about eight years—meaning that photovoltaics must grow no faster than about 12 percent annually in order to qualify as a net carbon dioxide mitigator. But in fact, photovoltaics grew at annual rate of 40 percent from 1998 to 2008, and at 59 percent between 2008 and 2014. Thus photovoltaics have been a net emitter for years. For photovoltaics to replace fossil fuels in electricity generation alone (never mind in transportation or other areas)—while growing no faster than carbon “payback” permits—perhaps 50 years will be required. Fifty years is simply too long to wait for fossil fuel replacement.

Wind power has an altogether different problem, as shown by recent research on wind farms in Kansas. This research indicates that turbines on large wind farms, as they remove kinetic energy from atmospheric flow, reduce wind speeds and thus limit generation rates. This is one reason that deployable wind energy represents a miniscule resource when measured against current energy demand. Wind energy simply cannot replace fossil fuels (even as it introduces environmental problems such as bird mortality).

Though I disagree with the technological optimism expressed by Huq, Stephens, and Wilson—optimism grounded in micro-experiences rather than a global picture of energy demand, barriers to deploying renewable energy, and the like—I agree with them on certain points. I agree with Huq, despite the problems associated with renewable energy, that “transitions from fossil fuels to clean-energy technologies must become the norm in every country—rich and poor alike.” I agree with Stephens and Wilson that overcoming political, institutional, and cultural resistance to change is a key part of energy transitions (which, to me, include establishing global energy equity and reducing energy consumption).

Indeed, if solutions to non-technical problems can be implemented, emissions can be reduced quickly and significantly—buying time for improved solar technologies to mature and be deployed. But the solutions I have in mind likely differ from those that my colleagues envision. For example, I envision the world softening and ultimately eradicating national borders. This might immediately eliminate about 10 percent of global emissions because standing armies, with their massive emissions, would be reduced to a minimum. And people would, as they did for millennia before fossil fuels emerged, go where the energy is rather than the other way around, reducing both emissions and energy transport costs. Banning fossil fuel–based air and private surface transport might eliminate another 10 percentof emissions. Shrinking cities and re-ruralizing the world could save an additional 10 percent. Such changes, if made, would start the world on a path toward sustainability, peace, and equality.

The way forward is clear. But the world’s willingness to embark on it is very much in doubt.

(Sagar Dhara researches and writes about energy, energy transformations, and risk analysis; advises people’s movements on the environmental impacts of industry; and is a budding organic farmer. Earlier in his career he was an environmental engineering consultant to the UN Environment Programme, a university teacher, and a director of Envirotech Consultants in New Delhi. He has had an activist streak throughout his career.)

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Bulletin of Atomic Scientists Round Table on Energy and Climate Change

Bright spots, big potential
Jennie C. Stephens, Elizabeth J. Wilson

The climate challenge is deeper than technology
Sagar Dhara

Climate change, renewable energy, and letting conventional wisdom go
Jennie C. Stephens, Elizabeth J. Wilson

Not a burden but an opportunity
Saleemul Huq

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2 Responses “How viable is renewable energy?”

  1. 30th May 2016 at 6:05 pm

    At first I was glad that Mr. Dhara has raised the viability question in connection with the renewable energies. While reading the article, however, I realized that he has not mentioned the main constraint that makes solar-electricity technologies unviable.
    I will come to that below. But first let me point out that the constraints he speaks about are not really insurmountable. He mentions “carbon dioxide payback period” and writes: “Photovoltaics must grow no faster than about 12 percent annually in order to qualify as a net carbon dioxide mitigator. OK, that is the macro-level problem. But if this technology grew, say, at the annual rate of 11 percent or less, then he would not have any problem? Today, that would be too slow to save the planet, right. But if somehow mankind had more time for the transition than 50 years, would then replacing fossil fuels with solar energy be viable? According to Mr. Dhara’s line of argumentation, yes.
    Mr. Dhara’s second constraint – limited reserves of rare earths and Chinese monopoly, or near monopoly, of the same – is also not an insurmountable constraint. Actually, it is only a question of price. I remember that in the 1950s, there was an Indian company by the name of Rare Earths Corporation (?) that was mining these minerals in Kerala. Some five years ago I read that these minerals are available in many countries of the world but that the cost of production at those sites would be higher than that at the Chinese sites. If the industrialists and other users of the world were prepared to pay a higher price, then other sites could be developed. That has happened with oil-sands of Canada and shale oil and gas.
    Mr. Dhara’s third constraint: “Meanwhile, renewable energy technologies that could function without rare earths, particularly photovoltaic technologies, are not close to commercial deployment.” This is no problem for technology optimists. They would reply: wait a year or two; then they would be commercially competitive.
    Let me now come to the constraint that is really insurmountable: It is that the intensity of solar radiation at any latitude on the earth’s surface is a cosmological constant that we humans cannot change. We can reduce it through some or other geo-engineering technology, but we cannot increase it. It may change, but in a billion years or so from now. And an earthly constant, which too we cannot change, is that the sun does not shine in the night.
    Because of these constraints, the energy payback time (EPBT as distinct from carbon dioxide payback time) is limited at one end of the equation. At the other end, technology can of course be improved. That could reduce the EPBT or increase the EROEI. But technological miracles cannot be expected in this area – for reasons I have discussed elsewhere (1).
    ———————–
    (1) See my blog http://eco-socialist.blogspot.de/search?q=Krugman

    Notes:
    I have discussed the whole energy problematique in great detail in my book Eco-Socialism or Eco-Capitalism? (ch. 4)
    The idea of a cosmological constant comes from Nicholas Georgescu-Roegan’s paper on solar energy.

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