Perhaps the most significant limit to future energy supplies is the “net energy” factor—the requirement that energy systems yield more energy than is invested in their construction and operation.
Searching for a Miracle report cover

Searching for a Miracle: ‘Net Energy’ Limits & the Fate of Industrial Society
Post Carbon Institute & International Forum on Globalization - September 2009



THIS REPORT IS INTENDED as a non-technical examination of a basic question: Can any combination of known energy sources successfully supply society’s energy needs at least up to the year 2100? In the end, we are left with the disturbing conclusion that all known energy sources are subject to strict limits of one kind or another. Conventional energy sources such as oil, gas, coal, and nuclear are either at or nearing the limits of their ability to grow in annual supply, and will dwindle as the decades proceed—but in any case they are unacceptably hazardous to the environment. And contrary to the hopes of many, there is no clear practical scenario by which we can replace the energy from today’s conventional sources with sufficient energy from alternative sources to sustain industrial society at its present scale of operations. To achieve such a transition would require (1) a vast financial investment beyond society’s practical abilities, (2) a very long time—too long in practical terms—for build-out, and (3) significant sacrifices in terms of energy quality and reliability.

Perhaps the most significant limit to future energy supplies is the “net energy” factor—the requirement that energy systems yield more energy than is invested in their construction and operation. There is a strong likelihood that future energy systems, both conventional and alternative, will have higher energy input costs than those that powered industrial societies during the last century.We will come back to this point repeatedly.

The report explores some of the presently proposed energy transition scenarios, showing why, up to this time, most are overly optimistic, as they do not address all of the relevant limiting factors to the expansion of alternative energy sources. Finally, it shows why energy conservation (using less energy, and also less resource materials) combined with humane, gradual population decline must become primary strategies for achieving sustainability.

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Reader Comments


Report: Searching for a mircle

From: Moisha Blechman, Jul 6, 10 06:05 PM

I think this is a well written and intelligent report that should be read by all, especially our senators who wrote the bill, The American Power Act under consideration at this time in the Unite States Senate.

However, as useful and important as the concept of evaluating an energy source in terms of the energy required to make it a source, or its net energy value, I think the evaluation of a source has to go through another test. This test must be a part of the final equation.

Once the net energy gained is evaluated, it must also be evaluated in terms of the economic loss as a result of environmental destruction or contamination. Especially in a rising population, it is crucial to examine an energy source in this light since the consequences of the fossil fuel based industrial society is literally killing vast expanses of this earth.

A good example of an extraction technique that is failing both tests is the tar sands of Canada.

Suggestions for future dialogues

From: William R. Adams, M.D., Mar 15, 10 08:26 PM

Global and local Carrying Capacity has not yet been adequately discussed (or faced). William R. Catton, Jr. would be a good candidate for such a dialogue. His recent book, "Bottleneck" introduces the concept of "Homo colossus", a moniker chosen to clearly show how fossil energy enhances (by manyfold) humankind's ability to alter (damage) the biosphere on which we are mortally dependent. Another topic would be with what do we replace the unsustainable fractional banking economic system that currently powers our dying economic system. Sustainability Economist Herman Daly comes to mind as a first rate candidate to discuss these issues. I enjoyed the "good news" brought by always enjoyable Lester Brown, but let's not forget that there is also a lot of permanent bad news that needs to kept on the radar screen to guide our practacal planning for the different future we face.

Solar Thermal

From: Adam, Mar 3, 10 05:23 AM

I agree with Patrick insofar as I couldn't see in the references where the EROEI of solar thermal (given a near-useless 1.6) came from.

energy sustainability

From: Angel Rodriguez, Mar 1, 10 01:26 PM

I would have to agree with this as a preliminary conclusion. The issues and our responses to this conclusion have to do with our values and personal interests. If we look at sustainability, energy scientists agree that our switch to large scale use of renewable energy sources will sustain us, however not in the economic manner in which we as Americans have grown up in. I think one of the issues to realize and come to terms with is that industrialization was an important and likely direction in its time and although the environment was giving us clues in the 1970's that we were heading in the wrong direction, we had already created our entire infrastructure and our economic system depended on the idea of unlimited resources. Here we are now waking up to the truth of finite resources and the shocking results of industrialization to other nations and the entire planet. It is what it is, but now, knowing what it is, we have an obligation to live sustainably within our commmunities, and within our own nations. We are all learning. This is a process that has no pat answers and no time to dwell on who is to blame. There is not enough time or money for large scale transition if we put our resources to war, nuclear energy and patching up our sinking economic ship. Its been great, but now its time to think long-term about future generations. We begin with conservation and switch to appropriate technology for our location. So although we have enough technology right now to sustain us, it will not now, not ever be enough to sustain the economic thinking that has brought us to where we are today.

hemp oil can save society

From: myles, Feb 26, 10 01:18 PM

Hemp oil is factually speaking the most efficient, non-polluting, abundant oil on planet earth. Oil...the dirty stuff humans have been consuming never had to be. Henry Fords first vehicle was completely made from hemp.

I disagree there are no solutions, but I do agree with the fact even if hemp oil was implemented in our society to replace all forms of polluting energy we will still facer an energy crisis of historic proportions.

Hemp seeds are also highly nutritious. This plant could save the world. WTF people get this information out hemp oil can replace all fossil fuels/nuclear/wind (because of possible health effects)

Per acre no other plant but hemp can produce more yield, bang for the buck and CLEAN energy, food and everything else we use in society.


From: dennis mchale, Feb 24, 10 06:17 PM

I've been saying for so many years now; that in order JUST to stay on the planet, we have to depose the centralized delievery system. Options are the small clouister townships powered by PV electric. There is much reinvention required; or we don't get to live here, simple really.
Thank you,
Dennis Mc Hale
Canyon Land Conservation Fund

Energy Conservation and Compounded Interest

From: Adolf from Austria, Feb 24, 10 10:14 AM

The most important function of money is to serve as an exchange mean for real values(goods). Otherwise compounded interest lets money volume grow exponentially. Please, explain me: How to conserve energy in an economy with limited resources but based on compounded interest?

not much time...

From: Plan B Economics, Feb 21, 10 07:29 PM

I'd say we're close to the edge...the current recession is simply a distraction.

More and more are predicting another 'crunch' within 3-4yrs:

RE Vegetarianism

From: Tod B, Feb 18, 10 03:03 PM

Paul -

You make a very good point. We were remiss in not mentioning this in the Case for Conservation chapter. This is not a small omission, and you we thank you for bringing it up.

Conclusions of the Report re: vegetarianism

From: Paul, Feb 18, 10 12:24 PM

Why did you not include a recommended switch to vegetable-based diet given its low energy input compared with meat?

Is the Energy El Dorado outside the 18+ Basket?

From: Chakradhar Mahapatra, Feb 3, 10 03:37 AM

Let's analyse this. The Indian Govt. will shortly sell spectrum(frequency) to mobile companies for billions of dollars. A few decades back, who on earth thought that a govt can raise money by selling a non-physical entity like frequency sepectrum?

Probably the answer for searching an energy miracle lies in technology & ideas rather than the current 18+ menu. I think connservation will not take us very far; technology & ideas will. Remember oil, with a life-span of about 200 years, was discovered only in 1858

Patrick - A Reply

From: PCI, Feb 2, 10 06:51 PM


Your concern for an accurate assessment is well taken. We do think that, if you take a look at Richard's take on solar thermal, it receives one of the most optimistic takes:

Like PV, active solar thermal makes use of a renewable source of energy (sunlight), and there is enormous potential for growth. In the best locations, cost per watt of installed capacity is competitive with fossil-fuel power sources. Solar thermal benefits from using already mature power plant technology and needs less land than a photovoltaic array of the same generating capacity.
The energy balance of this technology is highly variable depending on location, thus few studies have been done. In the best locations (areas with many sunny days per year), EROEI is likely to be relatively high.
There is considerable potential for utility-scale deployment of concentrating solar thermal power. Some analysts have suggested that all of the world’s energy needs could be filled with electrical power generated by this technology....
[F]or nations that lie sufficiently close to the equator this appears to be one of the most promising alternative sources of energy available. [52]
Concentrating solar thermal plants in Spain are now testing a heat storage module, [53] which can maintain power delivery during nights and perhaps longer periods of low sunshine. Since thermal energy is much cheaper to store than electricity, this could represent an advantage over wind or PV power if the Spanish tests are successful.

Solar Miracles

From: Patrick, Feb 2, 10 06:48 PM

Having read Heinberg's 'Searching for a Miracle', I have to disagree with the analysis. I agree that most alternative energy sources are unlikely to replace fossil fuels, especially oil. There is one technology that gives me hope, and that is solar thermal with molten salt storage, which is providing solar electricity day & night over in Spain. Heinberg's EROEI analysis of solar thermal was non-existent and he did not explain any assumptions or basis in the book, but I think his calculated EROEI was ridiculously low. I like the work of PCI, but I cannot endorse Heinberg's 'we are doomed no matter what' message - we are still in with a chance.