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Our Energy Vocabulary: The Words We Use for the Stuff We Can't See

It’s hard to talk about energy. Just ask any science teacher who has tried to define energy in a classroom. People stare blankly when you say, “It’s the ability to do work.” They furrow their brow when you tell them it’s not the same thing as “power.” You lose them completely if you bring up the laws of thermodynamics.

And yet, this thing that defies simple definition is critical to everything we do. Energy is fundamental to all facets of life on Earth. So it’s no surprise that folks who spend their days talking about energy have had to develop a special vocabulary, in order to have concrete discussions about an enigmatic concept.

In particular, if you want to talk about the effect that energy sources have on the environment, there is a large variety of phrases to choose from. Let’s look at a few of them, based on a literal interpretation of the words.

Concerned about pollution? Try clean energy. Afraid of running out of fossil fuels? You probably want renewable energy, or perhaps sustainable energy (more on these later). Is climate change your biggest worry? You may want to promote low-carbon energy. There is also alternative energy, which is attractive to people who know that they don’t like fossil fuels, but don’t want to specify exactly why. Even more vague is green energy, which refers to nothing specific at all and simply labels the person who says it as pro-environment.

Words come and go over time

With this long menu of phrases available, you might wonder which ones are used most often. Google Ngram Viewer lets you graph how often a word or phrase has appeared in books written in recent history. Plotting the five phrases below, we see that “renewable energy” has been the forerunner since the late 80’s.

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Percent of books written in English that include various energy phrases, 1970–2008. Plot from Google Books Ngram Viewer.
 
(I wonder happened in the early 80’s to cause publishing on both “renewable” and “alternative” energy to take a temporary dive. If you have thoughts on this, please comment.)
 
[UPDATED 4/10/2015: Commenter Bruce McFarling points out that the 1970’s were a time of increasing oil prices, and thus increasing interest in alternatives to oil. Indeed, the trajectory of inflation-adjusted oil prices bears strong resemblance to the red and blue curves above.]
 
Google Trends data confirm that “renewable energy” is also consistently the preferred term for curious readers. “Green energy” is relatively more prominent in online search than it is in print.
Image
Relative web search prevalence worldwide, 2004–2015. Plot from Google Trends.
 
Thinking harder about “renewable”

When it comes to making the public more aware of energy issues, I’m in favor of any and all phrases that motivate people to be conscientious energy consumers. The words “clean,” “green,” “renewable,” “sustainable,” etc. are great ways to remind people of the connection between energy and the environment.
 
But if you look beneath the surface, there are some important nuances that go into determining the words that experts use to talk about energy. Take nuclear energy, for example. Nuclear fission requires uranium mined from the ground. While the known reserves of uranium are fairly large, we can’t get more uranium after it’s gone, so nuclear energy is not renewable.
 
ImageNow consider geothermal energy, which is commonly referred to as a renewable energy source. When underground hot water is tapped to generate electricity, the lost heat is then replenished over time from the large reserves of heat inside the planet. (See Chapter 4 of this IPCC special report for some helpful information on geothermal energy.) While the amount of heat stored in Earth’s core is massive (~1031J), it is also finite. We can’t get more after it’s gone. So is geothermal energy actually renewable?
 
For that matter, what about solar energy? Solar is considered the epitome of “renewable,” but sunlight itself is also technically a finite resource. Eventually the Sun will turn into a red giant and consume Earth, at which point I’m pretty sure our solar panels won’t work anymore. To avoid this kind of semantic quibbling, many people (especially fans of nuclear energy) prefer the word “sustainable” to describe energy sources which humans could continue to exploit for many, many years.
 
Sustainability is complicated

Just like “renewable,” the definition of “sustainable” depends on many factors, including the timescale and the rate of resource extraction. If the reserves of a particular resource are very large relative to how much we are using, then its use might be called “sustainable,” because we don’t need to worry about running out any time soon (depending on your definition of “soon”).
 
But that’s not the end of the story. Sustainability is a higher standard than simply having “enough” of something. Our social, environmental and economic systems are enormously complex, and no one resource can be extracted and used in isolation. To be fairly labeled “sustainable,” our energy usage should not damage or disrupt other important resources, such as the air we breathe or the water we drink.
 
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It is also important to note that “sustainable” can be used as a relative term, just like “clean.” So nuclear energy is both clean and sustainable relative to fossil fuels’ impact on global climate, but it is dirty and unsustainable if you assume that the radioactive waste can not be safely contained.
 
Ultimately, “renewable” and “sustainable” should only be used to refer to practices of energy use, rather than to permanently label asource of energy. Energy from biomass is not renewable if we consume more biomass than we can produce each year. Burning fossil fuels is sustainable if we do it on a small enough scale.
 
These subtle distinctions can make it hard to fact-check any claims of sustainability. Luckily, there are tools we can use to analyze how our energy practices mesh with various complex systems. Life-cycle assessment is useful for quantifying the material and energy flows involved in a process, and resilience analysis can help predict the impact that a disturbance will have on an ecosystem. These tools are not perfect, but they are a good starting point as we look for a path forward that can actually be sustained.

Content Discussion

Jesper Antonsson's picture
Jesper Antonsson on April 9, 2015

Many good points there. I would go a bit further and claim that “renewable” is not a value-adding property, if we disregard the PR value, of course. Sustainable, scalable, environmentally sound, cheap, labor-saving and clean are all properties that are somewhat useful. Renewable and green, however, are devoid of any clear-cut advantages. And of course, “job-creating” is a negative property, even though it is sold as a positive one.

Also, as a nuclear fanboi, I’d like to mention that nuclear waste is extremely compact and very easy to contain for many orders of magnitude longer time than necessary. One demonstration of this fact is the natural reactors of Oklo.

Bruce McFarling's picture
Bruce McFarling on April 10, 2015

“(I wonder happened in the early 80’s to cause publishing on both “renewable” and “alternative” energy to take a temporary dive. If you have thoughts on this, please comment.)”

“Alternative energy” meaning alternative to existing conventional fuels, primarily driven by concerns from the US hitting domestic peak oil in 1968 and so oil price stabilizing power moving out of the hands of the Texas Railway Commission overseas into the hands of OPEC.

1983 was the time after the OPEC oil price shock when widespread cheating on quotas led to appreciable declines in the inflation-adjusted price of oil, so concerns of oil prices going up even further from their 1979 peak were fading. And in another few years, Saudi Arabia would open up the taps and the price of crude oil in real terms would drop back down to roughly the level post Arab Oil Embargo (the first oil price shock after price stabilization power passed outside the US).

cf, for example: http://www.intellectualtakeout.org/library/chart-graph/real-inflation-adjusted-petroleum-prices 

Bruce McFarling's picture
Bruce McFarling on April 10, 2015

“For that matter, what about solar energy? Solar is considered the epitome of “renewable,” but sunlight itself is also technically a finite resource. Eventually the Sun will turn into a red giant and consume Earth, at which point I’m pretty sure our solar panels won’t work anymore. To avoid this kind of semantic quibbling, many people (especially fans of nuclear energy) prefer the word “sustainable” to describe energy sources which humans could continue to exploit for many, many years.”

If we go to the source of the term, which is a distinction in resource economics between renewable resources and nonrenewable resources, this is not just semantic quibbling, but its not even a valid quibble. A resource is a source or a supply from which a benefit is produced, so an energy resource is a source or a supply where the benefit that is produced is provision of usable energy. A non-renewable resource is a resource that is formed over very long geological periods, while a renewable resource is a resource that can be replenished or renewed relatively quickly.

When we consider the heat death of the earth when the sun becomes a red giant in the normal life cycle of stars, earth-based beneficiaries are extinguished at that point{+}, so continued replenishment of the renewable resource past the heat death of the earth is a moot point. If the argument for instructing economists to abandon the distinction between renewable and non-renewable resources is based upon invalid quibbles, I would predict that the distinction is not going to be abandoned. // {+ Unless they’ve sorted out how to live inside a red giant, in which case they would likely to be continuing to use the solar power as a renewable resource.}

Naturally occuring uranium and thorium are non-renewable resources, however, particular radioactive isotopes of uranium could be considered a renewable resource in the context of breeder reactor fuel cycles (since the breeder reactor replenishes the supply of the isotope).

The total heat contained in the earth would be a non-renewable resource, if we had some way to use the total heat contained in the earth as a resource. If all we can use as a resource is the heat at some specific location underground, and it can be replenished by heat from the neighboring vicinity, that would seem to qualify under the technical term.

Of course, the distinction in resource economics is not “non-renewable bad, renewable good”, but rather “non-renewable and renewable require distinctively different methods and models to analyze effectively”. If advocates of increased reliance on sustainable, renewable energy resources have gained a PR advantage from the fact that their resource would be described as renewable by a resource economist, that does not say that advocates of use of a (partly or entirely) non-renewable relatively abdundant, low-carbon energy resource should lobby for the abandonment of what is a quite useful distinction in its field … it rather suggests that those advocates of a possible abundant, possibly sustainable energy resource out to work on getting better at PR.

 

 

Anna P. Goldstein's picture
Anna P. Goldstein on April 10, 2015

Good point, and thank you for sharing. Post updated to include the suggestion.

Bob Meinetz's picture
Bob Meinetz on April 10, 2015

Bruce, since you have an admirable preference for technical terms, I’ll point out that energy is one. It’s a quantifiable entity measured in units of ergs, kilowatthours, and joules (and several others). Resources is a fuzzy unquantifiable – it makes no sense whatsoever to speak of “24kWh of energy resources”.

I don’t believe I’ve ever seen “solar energy” casually defined as “solar energy resources” until your posts here on TEC. Is that an invention of your own, and if so, why should anyone be expected to accept it retroactively?

Anna P. Goldstein's picture
Anna P. Goldstein on April 10, 2015

My goal is not to change the terminology used by resource economists, but to encourage more thoughtful use of “renewable” in public discourse. It is very common to hear the message of, as you say, “non-renewable bad, renewable good” in certain segments of the media when covering energy. I think this sows confusion, because it’s not clear to a layperson what “renewability” has to do with preventing pollution and climate change. 

Bruce McFarling's picture
Bruce McFarling on April 10, 2015

I don’t believe I’ve ever seen “solar energy” casually defined as “solar energy resources” until your posts here on TEC.”

This is not surprising … unless you had been following the discussion of renewable resources since the 80s, you would likely have to be reading serious work on solar energy resources in resource economics or environmental economics to encounter it expressed in that way, and it would be unsurprising if you have never done so.


Robert Bernal's picture
Robert Bernal on April 10, 2015

I like to define renewable as “more than what we can use in the long foreseeable future”, sustainable as the “abiltity to power its own growth (and ours – and in the developing world, too), and ecological (or green) as simply not affecting the environment in a way that is not acceptable as observed by the scientific methods.

Renewable might not be sustainable (enough) per Eroei on an economic basis (and possibly, even the physical basis in some cases, like corn ethanol). This also must cosider ESOI (for energy stored on investment for storage) for an overall EROEI of entire collection and storage and distribution system. Sustainable might not be perfectly green and green most probably will not be sustainable unless its chemical and radiological wastes can never exceed the normal background levels past observed unsafe levels.

All sources have nasty byproducts, except those green sources which can only power a small percentage of today’s (and especially, the future’s) world, in which case, is like the wood smoke from chimnies located very sparsely, or old fashioned water, wind biofuels and solar basics. Today’s solar requires chemicals to be recycled, contained or neutralized for both batteries and collection (so that tomorrow’s solar can really kick butt). Wind might require bird herding quad copters (if possible) and geothermal is just the use of natural nuclear – which probably means that we should also learn the mastery of man made nuclear in the most efficient and safe way, too.

I appreciate the fact that you are using science to make “green” a much larger percentage of our energy sources! 

Bruce McFarling's picture
Bruce McFarling on April 10, 2015

“My goal is not to change the terminology used by resource economists, but to encourage more thoughtful use of “renewable” in public discourse.”

However, it seems that your proposal is to use “sustainable” instead of “renewable”, and then to use “sustainable” accurately … whether the useful energy can continue to be delivered at that level and in that way on an ongoing basis with neither significant depletion nor significant accumulating adverse consequences.

Hence, if the (non-renewable) natural uranium resource that is available at economic costs would be depleted within this century using once-through LWR fuel cycles, the energy delivered by once-through LWR fuel cycles would be unsustainable, while if the (non-renewable) natural uranium (and/or thorium) resource available at economic costs combined with renewable radioactive isotopes in some form of breeder reactor would not be depleted in a thousand years or more, and contingent on effective fuel security and sustainable waste disposal regimes, the energy delivered by those fuel cycles would be sustainable energy.

So one would be “unsustainable energy from nuclear power plants”, while the other would be “sustainable energy from nuclear power plants”.

Or if biomass is obtained from monoculture corn grown using a heavy fossil-fuel inputs, engendering depletion of soil fertility and selecting for insect pests, weed plants and plant diseases that are resistant to existing insecticides, herbicides and fungicides converted into ethanol for little or no net energy gain, or from clearcut old growth forests for torrified wood combusted with substantial air pollution, that is not sustainable, while if it is grown on marginal grassland or woodland soils with sustainable, low input cultivation of perennial prairie plant or coppiced wood production (either of which are typically soil-building rather than soil-destroying fiber producers), converted into stable biocoal with effective treatment of exhaust gas, used as an electricity co-generator, and converted into electricity using a technique with little or no air pollution, that would be sustainable.

So one would be “unsustainable energy from biomass” and the other “sustainable energy from biomass”.

But as far as “renewable”, it seems that for anyone following the approach recommended in this post, using renewable “in a thoughtful way” amounts to just not using it at all, which doesn’t seem likely to do anything to change the way that “renewable” is being used.


Engineer- Poet's picture
Engineer- Poet on April 10, 2015

Detail: the US didn’t hit peak conventional oil until 1970.

Bob Meinetz's picture
Bob Meinetz on April 11, 2015

Bruce, I’ve been following the discussion of solar energy since the 1970s, and that’s why I ask. Your definitions get more displaced from accepted scientific terminology the more you try to explain them.

A resource is  a “stock or supply” of something. Where in the universe is solar energy stored? I would love to see a link to any serious work which misuses the physical term energy as cavalierly as you claim it is. Can you provide one?

Bruce McFarling's picture
Bruce McFarling on April 12, 2015

You do not seem to have a firm grasp of the meaning of the word “or” as used in that sentence which, even if “source” is replaced by “stock”, does not modify that fact that supply is sometime a stock and sometime a flow.

Solar energy is not stored anywhere, it is generated outside of the (open) system in question and enters the system as a flow. So the strategy of your comment is to, (1) give a misleading description of a resource that gives the false impression that resources are restricted to stocks and exclude flows and (2) challenge where the stock is of something you and everyone reading knows full well is a flow.

You do not appear to be engaging in honest discussion. Instead you appear to be attempting to score debating points on some internal mental scorecard.

 

Bruce McFarling's picture
Bruce McFarling on April 12, 2015

I like to define renewable as “more than what we can use in the long foreseeable future”, sustainable as the “ability to power its own growth (and ours – and in the developing world, too), and ecological (or green) as simply not affecting the environment in a way that is not acceptable as observed by the scientific methods.”

But then we’ll need a word to refer to the distinction between the renewable and abundant non-renewable resources that you’ve lumped together as renewable, because the abundant non-renewable resources will still have reserves and extraction and the renewable resources will still have maximum sustainable annual yields … even if we decide to call both renewable.

The amount of previous extraction from a non-renewable resource will still modify the economic value of the remaining reserve, while the amount of previous sustainable extration from a renewable resource will still not modify the economic value of future harvest of energy from that resource … even if we decide to call both renewable.

They’ll still, in short, be physically and economically different in important ways, even in circumstances where both are useful, sustainable, sources of energy.

Also note that the ecological dimension of long term sustainability is not removed by that definition for sustainable, since the kind of ecological impacts that are not sustainable in the long term are the ones that undermine the ability to sustain growth, and if growth cannot be sustained as a consequence of using a power supply system, then that power supply cannot “sustain its growth”.

That definition may shift the spotlight away from ecological sustainability, but since we cannot simply assume the ecological viability of economic growth in the real world as so many of my colleagues do in economic growth models, it doesn’t actually remove ecological sustainability from the definition of sustainable.

Bruce McFarling's picture
Bruce McFarling on April 12, 2015

Bruce, I’ve been following the discussion of solar energy since the 1970s, and that’s why I ask. Your definitions get more displaced from accepted scientific terminology the more you try to explain them.”

My definitions haven’t moved: renewable versus non-renewable resources is a standard topic in resource economics, and I’ve used standard general definitions from resource economics.

I do prefer the more general definitions as more broadly useful in rural development in low income nations and in agricultural economics, and so haven’t used the more specialized definitions, particular to resource economics as such. They are more specialized to theories of economic values of resources using marginalist economic modeling. However, given the difficulty that you have been having in grasping the more general definitions, I do not think that shifting to the more specialized ones would allow you to gain much more traction.


Bruce McFarling's picture
Bruce McFarling on April 14, 2015

Apologies, that’s correct, 1970. Also note another factor in reducing the draw of “alternative energy” was that there was increasing production in the lower 48 in 1982-84, which combined with Alaskan oil reaching its peak in 1988 led to a local peak in 1985, at ~93% of the 1970 peak.

1968 is rather the beginning of the period, 1968-1973, surrounding the domestic conventional peak when we outproduced the 1985 local peak.

Bruce McFarling's picture
Bruce McFarling on April 12, 2015

Renewable and green, however, are devoid of any clear-cut advantages.”

If “green” means environmentally clean and sustainable, then it refers to clear cut advantages, but does not refer to them clearly, since environmentally clean and sustainable are clearer ways to say it. As a short-hand without its own intrinsic meaning, it runs a risk of debasement … but any of these terms do, eg, “clean coal”.

Renewable has the appeal for local economies of promising a local economic benefit that doesn’t run out. Many a town in rural America has experienced employment booms and then busts based on exploitation of a non-renewable resource that then becomes depleted.


Jesper Antonsson's picture
Jesper Antonsson on April 13, 2015

To me as a European, green is a very political term. Green movements were generally founded on opposition to all things nuclear, and due to organizational inertia, this remains a core element of Green thinking today. Sadly, it doesn’t seem to matter that the climate threat that has since emerged as the major environmental threat, nor that nuclear has now proven itself to be extremely clean with very mild accident modes.

A promise of renewable’s local economic benefit? Perhaps, but can it deliver? I think it cannot. There will be construction booms and busts in renewables too. Just look at how wind installations in the US went from 14 GW in 2012 to 1 GW in 2013. Sure, maintenance jobs will be more stable, but the construction I think is dominating. And again, the electricity is the good produced, while the jobs required is the expense.

Bruce McFarling's picture
Bruce McFarling on April 13, 2015

“And again, the electricity is the good produced, while the jobs required is the expense.”

For a profit making enterprise, to be sure, but for stakeholders in a local economy, that expense is often the point of encouraging the economic activity.

“To me as a European, green is a very political term.”

Its fuzzier in the US, since the entrenched electoral institutions put in place in the late 1800’s that suppress third parties at the expense of prospective parties of government means that “green” as a generic description of a number of environmental and ecological movements than of the small and very low-impact “Green” parties.

Bob Meinetz's picture
Bob Meinetz on April 13, 2015

Bruce, your continued evasion of providing any links to these supposed references would lead any rational reader to believe they’re fabrications.

If that’s the case, there’s no amount of abstruse pseudo-technical jargon which will be of help. Links, please.

Bob Meinetz's picture
Bob Meinetz on April 13, 2015

Bruce, deficiencies in your chosen technology don’t permit you to make up your own definitions for words, and the fact that you know something “full well” is wonderful, but an abysmal position from which to be arguing.

Please provide a link to a definition of resource which includes the word flow, or don’t continue to waste your readers’ time. Words matter.

Robert Bernal's picture
Robert Bernal on April 13, 2015

In the long term, all energy supplies will have to be from a “green” source (minus any small amount of “dirty” that the biosphere can absorb). But for now, it might be wise for humanity to consider what green sources can better sustain themselves at the level of today’s (and especially the future’s) required energy inputs. Since we are mostly powered by fossil fuels, most people still think that anything non polluting is the solution without considering if they can actually power their own growth. It is easy to make wind, solar, batteries and nuclear power plants with fossil fuels but will it be so when it’s fossil fuels turn to die?

Usually, I say that biofuels can not power the majority, however, biofuels should be able to be used for building just the energy infrastructure without “over harvesting” since the Eroei of each will at least multiply the biofuels inputs by 10.

Batteries and other storage will subtract from overall multiplier to some degree depending on Energy Stored On Investment for whatever storage and of course, Capacity Factor of collection.

Also, solar, wind and nuclear will take a lot longer to recoup energy payback and thus, we’ll have to prepare for whatever challenges that presents, too.

Jeffrey Miller's picture
Jeffrey Miller on April 13, 2015
“For a profit making enterprise, to be sure, but for stakeholders in a local economy, that expense is often the point of encouraging the economic activity.”

This brings to mind the famous Milton Friedman story in which 

Milton recalled traveling to an Asian country in the 1960s and visiting a worksite where a new canal was being built. He was shocked to see that, instead of modern tractors and earth movers, the workers had shovels. He asked why there were so few machines. The government bureaucrat explained: “You don’t understand. This is a jobs program.” To which Milton replied: “Oh, I thought you were trying to build a canal. If it’s jobs you want, then you should give these workers spoons, not shovels.”

It is interesting how, despite a near unanimous consensus from economists that energy policies and technologies should not be evaluated based on their putative job creation potential (because they will not create a net increase in jobs), the job creation story never dies. There are stories on TEC to this effect on a weekly basis. 

One might imagine that the story changes if restricted to a local economy. If a larger economic unit like a state or country subsidizes a local industry, then it is true that in that local area, the number of jobs might increase. The problem with this is that these larger units also subsidize similar schemes in many other locales, so that in the end the net effect on jobs and productivity ends up being negative for everyone.  

 

 

Bruce McFarling's picture
Bruce McFarling on April 13, 2015

It is interesting how, despite a near unanimous consensus from economists that energy policies and technologies should not be evaluated based on their putative job creation potential (because they will not create a net increase in jobs), the job creation story never dies. There are stories on TEC to this effect on a weekly basis.”

If you use a model in which you assume that the economy automatically moves to a full employment equilibrium if not “interfered with” by government, then certainly there will be little net employment impact … however there will still be some, if the employment multiplier of the new technology is higher than the employment multiplier if the technology it replaces. Most new technologies are a mix of resource-saving and resource-using, for various resources, and if we replace a technology with a higher share of value added going to natural resource rents with a technology with a higher share of value added going to payments for labor, it will have a positive impact.

But beyond that, in the real world we don’t actually live in economies that automatically move to full employment … and choosing to use the models which have that as a built in characteristic is begging the question on employment impacts, as the choice of model is itself a tacit assumption that no net new employment is possible by providing additional demand for products to increase the utilization of unemployed productive capacity.

And in the actual context here, where the US has only recently emerged from a five year labor market depression, then even if a substantial portion of the employment is, in the longer term, temporary employment from the buildout of new electrical generation capacity … if the buildout is two to three decades or longer, that’s still an appealing prospect. Especially if, unlike coal mining, the roll-out does not come to an end with ruined hills and streams and disabled miners slowly dying of black lung.

 

Bruce McFarling's picture
Bruce McFarling on April 14, 2015

Although I don’t recall seeing any prior request for links from you on the basic concept of a resource in economics, I have previously directed you to any basic text in resource economics for a discussion to catch up in this aspect of “renewable energy” (resources) that you’ve neglected over the past three or four decades.

If you are unaware of any place to find texts in resource economics, you could try Amazon, searching “Resource Economics” under books seems to turn up any number of likely candidates.

For an example of a treatment at a Principles level, refer to N. Gregory Mankiw (2012) Principles of Economics (International Edition). South-Western Cengage, SIngapore, p. 538. “Natural resources per Worker. A third determinant of productivity is natural resources. Natural resources are inputs into production that are provided by natures, such as land, rivers, and mineral deposits. Natural resources take two forms: renewable and nonrenewable. A forest is an example of a renewable resource. When one tree is cut down, a seedling can be planted in its place to be harvested in the future. Oil is an example of a nonrenewable resource. Because oil is produced by nature over many millions of years, there is only a limited supply. Once the supply of oil is depleted, it is impossible to create more.”

If you need more tutoring than that, I’ll gladly ask one of the Environmental Science instructors here to borrow their environmental science or resource economics text and give you some specific page references to get started.

 

Bruce McFarling's picture
Bruce McFarling on April 13, 2015

Usually, I say that biofuels can not power the majority, however, biofuels should be able to be used for building just the energy infrastructure without “over harvesting” since the Eroei of each will at least multiply the biofuels inputs by 10.”

But the lifetimes assumed for windpower for EROI in the 18-20 range are often 15-25 years. Its primarily solar PV where the lower EROI raises issues of how much growth in solar can be self-funding on an energy basis … raising the overall EROI and the self-funding capacity of the leading edge of the roll-out is therefore a matter of having something with both a higher EROI than solar PV and with a component of that with a substantially lower lifetime, and since much of the EROI for biofuel is driven by the feedstock, what is required for a medium term sustainable feedstock, a harvest cycle of under a decade, also reduces the average lifetime of the EROI for the biofuel.

We know that some 20%-30% of a renewable energy portfolio for very high renewable energy penetration should be dispatchable, and that the capacity for dispatchable hydropower in the US is somewhere in the 7%-10% range, leaving a gap on the order of 10%-23% to fill. Storage (grid scale or dispersed) can economize on dispatchable capacity required, but the economics of spreading the storage capacity over the number of annual uses of that capacity means that storage is most economically efficient for intra-day time-shifting of harvested renewable energy, which still leaves a substantial role for scheduled generation for inter-day firming. The energy self-funding side would be part of an argument of building that daily scheduled renewable generation capacity out in advance of when it is required for firming of the whole variable RE harvest of energy.

The first planning step to sustainable biofuels for electricity generation is to select the biofuel. We should obviously use all of the low hanging fruit available in terms of waste streams that are potential sustainable biofuel, but that low hanging fruit does not seem to be available on the 10%-20% scale.

Biocoal produced with contained and treated exhaust is already an R&D target, and offers flexibility in feedstock, reasonable thermodynamic efficiency, opportunities for immediate use in existing thermal plant, and opportunities for development of alternatives to combustion in direct carbon fuel cells, so it seems a plausible target for daily scheduled firming. It also allows for a natural market making floor in the form of guaranteed purchases of available biocoal for sequestration as biochar.

The first sequential step to sustainable biofuels is to have a sustainable cultivation, and since medium term sustainable cultivation practices will imply perennial plants with harvest cycles of well under a decade, the ramp up of medium term sustainable biofuels is similar to establishing any other new crop … find a way to make a market at a price that makes investing in the new crop an attractive proposition, and scale up the market making at a pace that keeps up with entry into the market.

At first glance, that looks like a time scale of a decade to establish the market and another decade to ramp it up substantially, which if we had an aggressive wind+solar roll-out would be roughly in line with the time frame of when existing capacity to firm wind+solar with hydropower and new transmission would be reaching its limit.

Bruce McFarling's picture
Bruce McFarling on April 14, 2015

But why would the definition have to include the word “flow”, when you already stated a definition that included the word “supply”?

From Mankiw, again, p. 73, sidebar definitions, “quantity supplied: the amount of a good that sellers are willing and able to sell.”

Since solar energy arrives on earth as a flow, the resource that sellers are able to sell is access to that flow. As you noted, there is no stock of sunshine, and sellers are not able to sell a stock of something that doesn’t exist, so the economic natural resource that can be supplied in a market can only be access to the flow. And I don’t deplete tomorrow’s flow of sunshine if I harvest some of today’s flow.

As far as “my chosen terminology”, where I’ve deliberately chosen a terminology, I am happy to explain why I chose the terminology that I have and to argue the case, but renewable versus non-renewable natural resources is not “my chosen terminology”, its simply the standard accepted meanings of the terms across resource economics. All of that was hashed out among resource economists quite a while ago, and the fact that it seems to be news to you doesn’t actually imply that its actually new.

Robert Bernal's picture
Robert Bernal on April 15, 2015

I agreee.

In order to complete a task, the most efficient means possible should be used unless the task itself is simply a “jobs program”, which at the expense of the “whole” is justified by means of education for the future of the working class.

The seriousness of meeting the challenges of global warming is not just a task and can not afford to be mired down by mere jobs programs. Thus this global physics challenge will probably not be completed on time by the mere political solutions.

The better approach is “100%” R&D and the “war effort”.

Bruce McFarling's picture
Bruce McFarling on April 16, 2015

The “mere jobs program” language seems designed to frame it as a policy choice between either leads to a increase in employment or else an effective policy. 

In the mainstream economic model, which typically assumes full employment in the long run, if the need really exists, and we make all of the right assumptions about real needs being reflected in effective demands, the minimum increase in employment required to satisfy that need will automatically occur, so no policy action is required to make bring about that part of any increase in employment, and an “employment intervention” is relative to that assumed full employment equilibrium.

But in the real world, making  scale of transition required to address the challenge of climate change, the result will require substantial policy actions which will bring about the required substantial increase in investment in the new infrastructure required for new ways of doing things, over a period of several decades. One consequence of a several decades long lift in investment in infrastructure will be a substantial increase in employment.

As we seek to build a political coalition in order to put those required policies into place (because policies do not get enacted just because “they are the most effective solution” … they get enacted because a political coalition pushes them through) … they are not “mere jobs programs”. However, they are policies that will lead to substantial increases in employment in “making” (and puting into place) “things that do things”, which is a kind of job that is appealing to a sector of the public who otherwise doesn’t care or doesn’t care deeply about the issue of climate change. I’m not seeing how leaving them out of the coalition makes the coalition more likely to succeed.

Jesper Antonsson's picture
Jesper Antonsson on April 16, 2015

No, the mainstream economic model (and empirical results) does not assume full employment, but it does predict that government mandated inefficiencies cannot hope to reduce NAIRU, or the natural rate of unemployment, other than very briefly and if you’re lucky with your timing.

If find the argument very dubious that we who are worried about climate change should exploit the lack of economic knowledge in certain segments of the population to increase policy acceptance. It will inevitably lead to misallocation of resources and thus likely to much slower progress. Choosing solar instead of nuclear is a very clear example of this. (And even if it were effective, choosing deliberate deception as a strategy is not something I can condone.)

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