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Posts tagged “eroi”

By Robert Rapier on Dec 22, 2011 with 39 responses

R-Squared Energy TV: Episode 6 – EROEI Explained

In this week’s episode of R-Squared Energy TV I present the first of several mini-presentations on energy topics of interest. The presentations will be short, 5 to 8 minute presentations with 3 to 5 slides each. This week’s presentation is on Energy Return on Energy Invested (EROEI). I believe there are a lot of misunderstandings from both proponents and opponents of EROEI methodology, and I attempt to clear up some of the misconceptions. Some of the questions answered are: What exactly is EROEI? Where might it be useful, and where might it possibly provide misleading answers? What are the societal implications of a declining EROEI? When is a lower EROEI process better than a higher EROEI process? What does EROEI… Continue»

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 Aug 9, 2009 with no responses

Answering Reader Questions 2009: Part 4

This marks the final installment of answers to questions recently submitted by readers. This final installment covers the impact of E10 on fuel efficiency, my general optimism (or lack thereof), algal fuel, thermodynamics and energy limitations, Accoya, and litigation. Once again, thanks to the readers who submitted questions, and thanks to those who helped answer them. Without the help I received, this might have been a 10-part series. Here are the links to the previous installments: Part 1 – Covered plasma gasification, natural gas projections, free energy, promising alternative energy technologies, and GTL Part 2 – Covered coal-to-liquids, technology hype, green gasoline, refining improvements, allocation of money toward renewables, electricity consumption, the Automotive X Prize, Big Oil, cellulosic ethanol, and… 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»