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Posts tagged “energy balance”

By Robert Rapier on Oct 31, 2011 with 42 responses

How Not to Use EROEI

This week I will be at the 2011 ASPO-USA Conference. I will deliver one talk on technical due diligence and one on our new energy reality. I will also participate in a roundtable discussion on investing. On the talk on our new energy reality, I am going to have a slide on my general observations over the past few years. One of those observations is that the concept of Energy Return on Energy Invested — EROEI — is frequently misused. The most common example is when people simply dismiss a process because it has a low EROEI or a net negative energy return. So as I am finalizing my slides, I thought I would share my EROEI observations here. What… Continue»

By Robert Rapier on Jul 7, 2010 with 63 responses

Fun with Numbers: The New USDA Report on Corn Ethanol

The EROEI of Ethanol Over the past decade, the United States Department of Agriculture (USDA) has published several papers in which they investigated the energy return of corn ethanol. The energy return on energy invested (EROEI) is simply the value of the energy outputs for a process divided by the energy inputs into the process. In simple terms, if a process required 1 BTU of energy to produce 2 BTUs of ethanol, the EROEI is 2. However, in reality it is somewhat more complex than that. The way the energy inputs and outputs are allocated can have a very big influence on the answer. Just by changing the nature of the allocation – as I will show below – you… Continue»

By Robert Rapier on Nov 14, 2008 with 3 responses

The Energy Return of Tar Sands

When evaluating energy technologies – whether conventional fossil fuels or alternative energy – one thing that I pay close attention to is the Energy Return on Energy Invested (EROEI). While there are legitimate criticisms of the methodology, it can serve as a useful tool for comparing and contrasting various alternatives. To give a flavor for why this is, consider an example. Let’s say society as a whole produces 50 million barrels of oil equivalents (could be oil, nuclear, wind, solar, biofuels, or a combination). Consider a couple of energy options. Option A has an EROEI of 10/1 (Energy Output/Energy Input). Option B has an EROEI of 2/1. Option A has to consume 5 million barrels to produce 50, for a… Continue»

By Robert Rapier on Mar 5, 2008 with 10 responses

Understanding EROEI

Introduction The concept of energy return on energy invested, or EROEI, is terribly misunderstood. I have heard people argue that EROEI doesn’t matter, only economics. This misses a very key point: EROEI is going to have a huge impact on economics, because it shows that in order to maintain current net energy for society, energy production must accelerate as EROEI declines. Likewise, I have heard people hand wave away the issue, suggesting it is really no big deal. Here’s an example that I saw yesterday in a thread at The Oil Drum: Consider an EROEI of 20 with 10 units required; this means that 1 unit is invested to get 20 unit of output or if 10 units are required… Continue»

By Robert Rapier on Jan 23, 2008 with no responses

Perpetual Confusion over Energy Balances

People continue to be confused about the energy balance of gasoline versus ethanol. The ethanol lobby, in my opinion, deliberately spreads this sort of misinformation to persuade people that producing ethanol is a wise usage of our BTUs. I have tried to clear up the confusion on a number of occasions, most recently when Vinod Khosla once again claimed “corn ethanol has almost twice the energy balance compared to gasoline“: The Handy-Dandy Khosla Refuter But the issue lives on, as strong as ever. A couple of days ago, Stuart Staniford wrote the following essay at The Oil Drum: The Fallacy of Reversibility In the essay, Stuart takes on one of the major tenets of many peak oilers: That peak oil… Continue»

By Robert Rapier on Nov 5, 2007 with no responses

High Oil Prices = High Biofuel Prices

You know that forever I have beaten the drum that high fossil fuel prices would make biofuels more expensive due to their poor EROEI. If you are unfamiliar with the argument, it is essentially that most biofuels have very high fossil fuel inputs (and thus a low energy return). That simply means that when fossil fuels get more expensive, biofuels eventually have to follow. I always thought it was funny when people thought just the opposite would happen: As fossil fuels get more expensive, biofuels become more competitive. That could very well be true if you had a ubiquitous source for biofuels that had minimal fossil fuel inputs. But that isn’t what we have. And the Wall Street Journal finally… Continue»

By Robert Rapier on Aug 9, 2007 with no responses

Bob Dinneen Responds to Rolling Stone

I know it’s been a bit heavy on ethanol lately, but I continue to get quite a bit of activity over the recent Rolling Stone article. That’s the whole reason for writing a FAQ. I have in the queue a half-finished essay on solar thermal, and would really like to delve into that topic a bit more. I don’t want to become “The Ethanol Blog”, but it seems like that recently. Bob Dinneen, President of the Renewable Fuels Association (the same association that claims displacement of 170 million barrels of oil with the energy equivalent of 64 million barrels of ethanol) wrote to Rolling Stone and addressed Jeff Goodell’s recent story: Letter To The Editor: Response to “The Ethanol Scam”… Continue»

By Robert Rapier on Mar 8, 2007 with no responses

The Handy-Dandy Khosla Refuter

The web site Seeking Alpha has just published a new article on ethanol: Ethanol: A Few Myths Debunked To be honest, there are so many misconceptions and myths in the article that a better name for it would have been Ethanol: A Few Myths Repeated. I think all of these “myths” have been covered at one time or another in this blog, but he does quote Vinod Khosla at length. So, this might be a good time to re-debunk Khosla, given that he has repeated this claims many times since the first debunking. So, once again, here are Vinod Khosla’s claims, repeated from the above article, dissected and debunked. VK: Energy balance is not even the right question to answer…. Continue»

By Robert Rapier on Sep 2, 2006 with no responses

Postscript with Wang and Khosla

I think the thread on efficiency of ethanol versus gasoline left a lot of things hanging, and there have been some communications with Dr. Wang and Mr. Khosla since then. So, I wanted to more or less close the book on this and share those communications. I don’t want to spend another 300+ posts arguing about efficiency, but I do want to let the readers know how this all turned out. Dr. Wang was clearly miffed about my usage of “sleight of hand.” While I do not consider usage of this phrase insulting, I felt like the right thing to do was to apologize since Dr. Wang took offense. So, I e-mailed back to Dr. Wang, Tom (who never again… Continue»

By Robert Rapier on Aug 25, 2006 with no responses

Battling with the Critics

Just when I thought I was out, they pull me back in. I am trying to spend more time writing on topics other than ethanol. But I get a lot of e-mails on that subject, and often have 3 or 4 mini-debates going on at a time via e-mail. I just finished a debate involving a government official and some big names over the energy balance of gasoline versus ethanol. There still seems to be a lot of confusion surrounding this issue, so I asked for permission to publish the exchanges. I was reluctantly given permission, provided I deleted the personal information from the government official (name and government agency). The exchange involved myself, a government official that I will… Continue»