PETROLEUM- Energy Density and EROIE


noun-the amount of energy stored in a given system or region of space per unit volume.


Energy density and the cost, weight, and size of onboard energy storage are important characteristics of fuels for transportation. Fuels that require large, heavy, or expensive storage can…learn more>>

enlarge graphic>>  DYK PETR fuel density


Energy content of fuels
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Gasoline contains, on average, 32 MJ/L. Actual energy content varies, by up to 4%, from season to season and from batch to batch[1]. On average, about 19.5 USgal of gasoline are available from a 42 USgal barrel of crude oil (about 46% by volume), varying due to quality of crude and grade of gasoline. The remaining residue comes off as products ranging from tar to naptha.[2]

Volumetric and mass energy density of some fuels compared with gasoline:[3] …learn more>>




EROEI=  energy returned on energy invested
EROI= energy return on investment


EROEI: A Useful Measure or a Distraction?

It seems so simple. If the amount of energy produced relative to the amount of energy utilized in producing that energy tends to decline, at some point as the ratio approaches 1.0 (or perhaps even becomes a fraction less than 1.0) there is little if any return on the energy invested and society will collapse. But is this concept really workable and useful?

There are many issues related to how this ratio (sometimes abbreviated as EROI) is calculated. This affects both the numerator and the denominator of the ratio. The first problem is that this equation is usually interpreted as being the useful acquired energy divided by the useful energy expended.
– Energy Quality
– System Boundaries
– Present Value
– Factor Prices
– Relationship to Net Energy Gain
– Typical current EROEI values
– EROEI Trends
– Relationship to GDP



Energy Return on Investment (EROI) for U.S. Oil and Gas Discovery and Production

Oil production in the US peaked in 1970. The easy “sweeter” stuff has been extracted. What remains is deeper in the ground or farther off-shore, requires much more energy to extract, and is more toxic to produce. It takes energy to make energy. Energy Return on Investment (EROI) also known as ERoEI (Energy Returned on Energy Invested), is a common way of expressing the efficiency of the energy production process. The EROI for oil and gas, as well as other fossil fuels, has been falling for decades (see chart below). If it was a financial stock, you would have sold it years ago….Learn more>>



Low Energy Return On Investment (EROI) Need Not Limit Oil Sands Extraction
By Rembrandt/June 10, 2013

– Introduction: Low energetic returns (e.g., EROI, NER) from oil sands extraction and upgrading have been noted as a potential limit to the development of the oil sands as a substitute for depleting conventional oil resources (e.g., Herweyer and Gupta, 2008). In this article we will examine this claim from a variety of perspectives….for an in-depth study and graphs click the links below>>
– Are energy returns from oil sands extraction lower than conventional oil?
– How have energy returns from oil sands extraction changed over time?
– What are the implications of oil sands energy sourcing for limitations due to low energy returns?
– Will low energy returns limit the output of net energy from the oil sands?


Diminishing Returns, Energy Return On Energy Invested, And Collapse
 By Gail Tverberg | December 6, 2013  

What do diminishing returns, energy return on energy invested (EROI or EROEI), and collapse have to do with each other? Let me start by explaining the connection between Diminishing Returns and Collapse. …Learn more>>

– Diminishing Returns and Collapse: We know that historically, many economies that have collapsed were ones that have hit “diminishing returns” with respect to human labor–that is, new workers added less production than existing workers were producing (on average). For example, …Learn more>>


– Why Might an Economy Collapse?
– Our Economy is Already in a Precarious Position
– The Government’s Role in Fixing Low Wages and Slow Economic Growth
– Debt is Major Part of our Current Precarious Financial Situation– The Role of Energy Return on Energy Invested (EROI or EROEI)
– Contributors to Declining Return on Human Labor




Oil Sands Mining Uses Up Almost As Much Energy As It Produces

Thanks to high global oil prices, industry can afford the large amount of energy needed to extract the oil and turn it into a usable fuel.
By Rachel Nuwer, InsideClimate News Feb 19, 2013

The average “energy returned on investment,” or EROI, for conventional oil is roughly 25:1. In other words, 25 units of oil-based energy are obtained for every one unit of other energy that is invested to extract it.

But tar sands oil is in a category all its own.

Tar sands retrieved by surface mining has an EROI of only about 5:1,…Learn more>>