‘Lure of the Renewables’ (Vaclav Smil in 1987 for today)

“Perhaps the most distressing characteristic displayed by the pushers of soft energy was the intellectual poverty of their grand designs, their impatient dismissal of all criticism, their arrogant insistence on the infallible orthodoxy of their normative visions.”

“There is little doubt about the origins and the real message of soft energy dogma: the roots are in the muddled revolts of young Americans in the late 1960s and the early 1970s, the goal is a social transformation rather than simply a provision of energy. The latter fact explains the widespread appeal of soft energy sources among zealous would-be reformers of Western ways.” 

Vaclav Smil is one of the leading energy scholars of our day. He has, time and again, tried to inject energy reality into energy fantasy. Some of his previous posts at MasterResource (see here) include ‘The Limits of Energy Innovation’: Timeless Insight from Vaclav Smil and the five-part Power Density Primer.

This excerpt is from Smil’s 1987 book, Energy, Food, Environment: Realities – Myths – Options (Oxford: Clarendon Press) and used with his permission. Nearly thirty years old, maybe now rather than then we realized that renewables is a limited option for mass electricity (and thus the eleventh-hour rescue of nuclear energy as a ‘clean’ energy by some environmental organizations).

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In societies prone to embrace uncritically any appealing panaceas the sermonizing of renewable energy enthusiasts was given very generous attention and regarded surprisingly often with awed reverence. Even among otherwise sensible engineers, whose lifetimes had been spent on perfecting designs and performances of technologies so they would fit the cost and reliability requirements of the real world, not a few were captured. 

When even some of the people who knew best the huge gap between conceptual designs, working prototypes, and rapidly diffusing commercial devices started to speak in tongues of a renewable tomorrow, how could the public media and popular scientific accounts be blamed for seeing every house heated by solar energy, every kilowatt-hour produced by photovoltaics, wind turbines, or ocean thermal conversion, every car running on alcohol?

Yet the appeal is not difficult to understand. In a world either rapidly running out of fossil fuels, or threatened by crippling environmental pollution following their further extended use, conversion to nuclear energy would be an even more dangerous proposition. 

With all the escapes closed only one solution remains, a massive adoption of renewable sources and technologies.  The most powerful part of the appeal certainly rested on the renewability of the flows to be harnessed—out there all the time, free to be captured with devices ranging from the simple to the ingenious, and with appealingly low costs.

Actually, the renewable inamorati invested their solution with a longish array of other, far from modest attributes.  Nobody spelled out these better than Amory Lovins, the most publicized guru of the new nirvana. 

He assured the nervous post-1973 world that harnessing of renewable energies, which ‘are always there whether we use them or not’ and which represent an enormous potential, would not only be ‘elegant’ but also economical, that the possibility of small-scale, decentralized operations would especially benefit the poor by contributing ‘promptly and dramatically to world equity and order’, that these designs ‘for democracy from the ground up’ would be safe and ecologically inoffensive, spreading the virtues of community resilience, self-sufficiency, and a sustainable future, a gentle balm of soft energy technologies healing the distressed planet.

Specific claims made by the uncritical proponents of renewable energy sources read like wishing lists in fairly-tales: William Jewell wrote that ‘development of marginal lands for biomass production of fuels could result in generation of the total U.S. energy requirement’; Bent Sorensen foresaw that residues from biofuels could replace all chemical fertilizers within 50 years; Donald Klass had a single 100,000 square mile desert area in the Southwest USA supplying two-thirds of America’s energy needs!

What a stunning combination of appealing features unalloyed by any drawbacks, literally oozing the confidence that the solution to global energy problems was at hand—what a crafty assemblage of generalities, a skillful manipulation of realities betraying more of a messianic zeal than a critical understanding of the complexities and limitations surrounding the use of renewable energies.  I am still astonished that such rubbish could have been published in scientific journals when a few minutes with a small calculator (and, of course, appreciation of basic biospheric realities) are enough to unmask the irrationality of such claims.  For example, to turn Klass’ scheme into realty such a gargantuan energy plantation would require daily eight trains made up of 100 50-tonne hopper cars to bring the requisite nitrogen, phosphorus, and potassium fertilizers and it would consume nearly 30 per cent of all surface runoff from the 48 contiguous United States!

But let us look at some of those superficially so persuasive general arguments in favour of the renewables—and the availability of renewable energies is a natural place to start with. There is perhaps no finer refutation of the claim that renewable energies are ‘always there’ than a closer look at the availability of solar radiation in the poor countries whose ‘fortunate’ location in the ‘sun-drenched’ tropics is supposed to be very advantageous, not only for direct solar conversions but also for the cultivation of high-yielding food and energy crops.

True, the area between the two tropics contains regions with the planet’s highest insolation, such as Southern Egypt and west-central Saudi Arabia, but it also contains the extensive inter-tropical convergence zone (moist tropics), and the large monsoonal regions where annual insolation is surprisingly low. And so most of the Brazilian Amazon, or all of southern Nigeria receive less radiation than Georgia or Kansas, and virtually all the very densely populated, poor places from Southern China through Vietnam to Malaysia, Sumatra, and Kalimantan have solar inflows comparable to those in northern France and southern England, the latter two being hardly the regions usually described as ‘sun drenched’.  Naturally, this does not make Manaus, Logos, Guangzhou (Canton), or Singapore unsuitable for collecting solar radiation by appropriate (i.e. flat-plate rather than concentrating) devices but, as in Philadelphia or London, it makes using direct radiation a good deal less practical, efficient, and reliable than in Tucson or Aswan.

The crop productivity myth, perpetually fostered by the rich, lush appearance of natural tropical vegetation, should not be around any more as it has been exposed many times in the past. In the dry tropics productive farming is predominantly confined to irrigated land and already severe water limitations will ensure the lasting priority of food and feed crops over biomass harvested for energy.  In the humid tropics yields of annual crops are depressed in comparison with temperate latitudes owing mainly to the previously mentioned lower insolation (during the summer growing season Amazonian, Zairian, Indonesian, or South Chinese ricefields receive 10-15 per cent less radiation than even the Canadian Prairies at about 50ºN) and to the relatively high minimum night temperatures promoting respiration losses.

The effects of reduced potential photosynthesis are further aggravated by water deficits (differences between the potential evapotranspiration and effective rainfall in many parts of the tropics are comparable to thosea of the temperate desert regions), often low fertility soils, and favourable conditions for diffusion of numerous pests and diseases. This unalterable climatic impoverishment of the tropics will always put the region at a disadvantage in growing highly efficiently all but a few specialized crops.  Counter-intuitive as it may be, even humid tropics cannot compete in growing food with temperate zones, and it then makes hardly any sense for countries which cannot feed themselves to turn large blocks of their farmland into sugar-cane or cassava fields to produce fuel alcohols and to sink even deeper into dependence on food imports.  Significantly enough, most of the populous tropical nations located fully or partially in the moist or monsoonal tropics are already large, and increasing importers of food!

In capturing the solar flow directly or indirectly through food and energy crops, many poor nations are thus already facing fundamental environmental limits which are dispelling erroneous notions of the tropics as an especially propitious region for an easy and swift establishment of modern renewable energy economies.

The infatuation with the enormous potential is due to an almost always overlooked difference in essential categories: what the uncritical proponents of renewable energy sources were almost exclusively citing were in fact, resource estimates rather than reserve assessments.  Biomass energy appraisal serves as an excellent example of this fallacy. 

Unlike the obviously intermittent solar-radiation flows, biomass appears to be always available, conveniently ‘storable’ in trees and crops and it has been assigned by renewable energy planners the essential roles of supplying liquid transportation fuels (alcohols), and generating electricity in small, decentralized (and hence supposedly less vulnerable) power plants.

Yet the impressively huge figures for the total national or regional availability of wood wastes or crop residues are analogous to our estimates of total oil in situ and these sets of resource estimates share a large range of uncertainty and a fundamental limitation: whatever the total resource might be, only a fraction of it will be recoverable.  While, in the case of crude oil, the recoverable reserves cluster around only one-third of the resources in situ, waste biomass recovery ratios may be still smaller.

A detailed feasibility study on the co-generation of electricity and steam by using wood waste as fuel in timber-rich Lewis county in Washington illustrated perfectly this discrepancy. The potential of logged fuel, sawdust shavings, chips, yard wastes, and all kinds of logging residues was found to be worth 115 MWe—but the effects of fluctuating annual forest cut, and lumber and plywood markets, alternative (and almost invariably more lucrative) uses for chips, sawdust, and merchantable cull logs, and prohibitive transportation costs for diffuse, low-density residues from remote sites, cut the feasible size of the facility to just 25 MWe.  Extractable wood waste ‘reserves’ were in this case only about one-fifth of the appraised resource.

A similar situation arises with the removal of crop residues. Again, a simplified estimate (usually based on very unreliable grain-to-straw ratios) will show a large potential energy resource, and theoretical calculations can be used to advise a farmer how much straw or stover he can remove from his fields without adversely affecting soil tilth and fertility, and without exposing the land to excessive erosion.  Yet such general recommendations may prove recklessly excessive in a year when the harvest is followed by a snowless, windy winter and dry, and no less windy, spring.  During the August or September harvest we have, of course, no way to predict the weather for six or nine months ahead, a simple reality forgotten by renewable energy proponents—but rarely lost on the farmers who are after all, playing a risk-minimizing game.

Consequently, a careful appraisal of straw availability in the heart of Kansas wheat country (Pratt county) had to conclude that concerns about wind erosion would limit a partial removal of residues to only some 20 per cent of wheat area, and that fields would have to be modelled individually to arrive at the allowable ‘extraction’ rates. Farmers’ perceptions were even more conservative: 60 per cent of the farmers queried in the county were unwilling to have any residues removed from their fields, and 40 percent would allow a partial removal from only a part of their land.

These two examples, coming as they do from the areas having North America’s richest concentrations of, respectively, woody and crop waste biomass readily convertible to energy, cannot be overemphasized. They are striking illustrations of the ever-present disparity between grand estimates of resources in situ and recoverable reserves in a particular locality, and they also illustrate that renewable options are not automatically elegant, ecologically inoffensive, and sustainable.

As we get down from generalities about renewable, inexhaustible, and environmentally benign resources to a close, pinpoint accounting of reliably available waste biomass whose extraction will be compatible with long-term preservation of soils, nutrient cycles, and water balances, the availabilities will shrink quite substantially.

Similar limitations would apply to harvesting the whole trees specifically cultivated for energy in projected fuel plantations. As Harold Young, the originator of the whole-tree utilization concept, aptly remarks, we can build a power plant and fuel it with short rotation trees in three years but scientific information regarding long-term effects on forest nutrients can easily take ten times as long to gather.  Yet before we possess such, usually highly site-specific, information we might be over-extracting the resource, degrading and eventually ruining its environmental foundations, and making it nonrenewable.

Preoccupation with smallness and decentralization has been an outright obsession with advocates of ‘soft renewability’ but in the real world there are inherent and predictable, as well as hidden and surprising, advantages and drawbacks to scales small and large: judging a technology solely by its scale is neither rational nor useful.  Small scale goes too often hand-in-hand with mismanagement, inefficiencies, high energy waste, and uncompetitive costs—as best illustrated by the prodigious Chinese experience with small-scale industrialization between 1958 and 1978.

The Chinese, the world’s leading promoters of self-sufficient smallness, concluded that the approach was not only wasteful but that it was clearly insufficient to provide a foundation for the industrial advancement which is so badly needed by all poor nations. In this respect power output considerations become critical.  Most operational technologies based on renewable resources can be, when properly maintained and run, very helpful to a rural household or a small village supply—but they cannot support such basic, modern, energy-efficient industries as iron and steel-making, nitrogen fertilizer synthesis, and cement production.

‘Renewable’ ironmaking provides the best example of scale mismatch. Charcoal would be the only practical renewable substitute for metallurgical coke and no less than 2.5 m³ of it are needed to smelt a tonne of pig iron.  Wood requirements for charcoal vary with tree species and kilning procedure but, by coincidence, 2.5 m³ should be taken as the minimum.  This means that securing enough charcoal for the current global annual output of 500 million t of pig iron would claim some 3.25 billion m³ of wood—and even if this wood could be grown in intensive (fertilized, irrigated) fast-maturing tree plantations yielding around 5 t per hectare, it would take an equivalent of nearly 30 per cent of the world’s farmland, clearly an impossibility.

This is just one example of an irremovable mismatch between high power densities of industrial processes (which require energy supplies at rates of 10²-10⁷ W/m²) and large cities (which consume energy at 10¹-10² W/m²) on the one hand, and low power densities of renewable energy supplies on the other.  Biomass fuels and electricity from wind cannot be produced with power densities higher than 10-¹ W/m², hydro, tidal, geothermal, and solar energies can be converted into heat or electricity with power densities of 10⁰-10¹ W/m²-—but still need storage to overcome random flows.  In contrast, fossil fuels can be extracted at densities of 10³ W/m², matching much more easily the needs of industrial civilization without exorbitant land requirements.

Poor countries need it all: two hot meals a day, higher crop yields, widespread industrialization. Obviously, going ‘from the ground up’ by means of small decentralized energy serices [sic] would not, costs aside, be without many local benefits, but a prompt and dramatic contribution to world equity would hardly follow.  After all, small-scale decentralized energy sources are still an everyday affair for the poor world’s peasants, and while replacing today’s inefficient rural stoves or open fireplaces with solar cookers and biogas digesters (providing local environmental and resource constraints would allow their operation) would be an important qualitative gain, it would still be only a partial one as growing populations, rapid urbanization, and higher food production cannot be managed without reliance on large-scale industrial processes.

About the economics of renewable resources little has to be said: claims of embarrassingly cheap energy deliveries have been based on a very limited body of everyday, long-term experience, and often the values represent just dubious guesstimates which only a few decades of cumulative experience can dispel. Until such time, most of the cost claims resemble nothing more than the cost appraisals of nuclear generation proffered during the 1950s.

Curiously, ‘soft’ energy proponents share even more with their counter-parts in the nuclear camp: both groups of proselytizers are bound, though none would admit this, by a misplaced and mistaken faith in technology as the solution for complex problems of energy supply. Zalmay Khalilzad and Cheryl Benard noted how the claims made on behalf of the renewable energy technologies are amazing carbon copies of earlier claims made on behalf of fission generation.  After a generation or two of buffeting in the real world these faultless utopias get a worn-out look!

Many more cutting comments have been made about the presumptuousness, fallacies, and fundamental flaws of soft energy schemes. Harry Perry and Sally Streiter pointed out that there is no evidence about the irreconcilable exclusivity of ‘hard’ and ‘soft’ paths which formed a basic premise of Lovins’ argument and asked a simple key, question: ‘How certain are we that the soft technologies can be successfully developed for widespread commercial use?’ Alvin Weinberg argued that the use of renewable sources may not be the best choice to satisfy important trade-offs of energy use and time savings, and that other considerations (environmental, economic, reliability) militate against simple-minded stress on maximum thermodynamic efficiency.

Perhaps the most distressing characteristic displayed by the pushers of soft energy was the intellectual poverty of their grand designs, their impatient dismissal of all criticism, their arrogant insistence on the infallible orthodoxy of their normative visions. There is little doubt about the origins and the real message of soft energy dogma: the roots are in the muddled revolts of young Americans in the late 1960s and the early 1970s, the goal is a social transformation rather than simply a provision of energy.  The latter fact explains the widespread appeal of soft energy sources among zealous would-be reformers of Western ways.

Michael Stiefel’s question cuts to the core: ‘What will happen when soft paths become superstition instead of heresy?’ I am afraid that in the way it was put out the ‘soft’ sermon was superstitious right from the start. That we need all workable, reliable, economical alternatives to diversify our current energy production is clear; we need renewables—not as a means to redeem our fossil-fuelled [sic] or nuclear sins, but as part of a complex effort respecting that enormous heterogeneity of natural endowment, environmental, and economic conditions, and available human skills and including all worthwhile conversions on any scale.

To worship a single, simple, infallible precept is not only to discard excellent available alternatives and pass up the opportunities for improving other approaches but, most unfortunately, to foreclose tomorrow’s choices: a soft thinking, indeed.