EROI of Global Energy Resources Preliminary Status and Trends (original) (raw)
Related papers
EROI of Global Energy Resources: Status, Trends and Social Implications
All forms of economic production and exchange involve the transformation of materials, which in turn requires energy. Until recently cheap and seemingly limitless fossil energy has allowed many to ignore the important contributions from the biophysical world to the economic process and potential limits to growth. The report that follows, commissioned by the United Kingdom’s Department for International Development (DFID) and developed by the State University of New York College of Environmental Science and Forestry (SUNY-ESF) and Next Generation Energy Initiative (NGEI), examines the energy used by modern economies over time. This work centers on assessing the relation of energy costs of modern day society and its connection to the quality of human life. A focus of this report is energy return on investment (EROI) and some important characteristics of our major energy sources over time. We find the EROI for each major fossil fuel resource (except coal) has declined substantially ove...
Impact of Global Energy Resources Based on Energy Return on their Investment (EROI) Parameters
Human development has been based on the use of the energy resources, especially those of fossil origin (oil, gas, coal, etc.), which are not infinite and damage ecosystems ; it is of paramount importance to make a transition to other alternative sources of energy. We compare and discuss many global sources of energy and their impact, based on the useful parameter called energy returned on energy invested or energy return on investment (EROI). In the long run we could expect renewed emphasis on enhanced (stimulated or hot dry rock) geothermal energy sources due to technological advances in deep drilling and the availability of this kind of energy 365 days per year and 24 hours of a day.
Nature Energy, 2019
T he field of net energy analysis first came to prominence during the 1970s oil crises 1-4 as a means of assessing how much energy is delivered to society. Various metrics have emerged 5 , including the energy profit ratio, energy gain, energy payback, and the most well-known: energy-return-on-investment (EROI). Kunz et al. 6 define EROI in its simplest form as a ratio that "divides the total energy output by the energy input". Several factors have contributed to increasing attention being paid to the EROI research field. First, there are concerns over declining EROI ratios of fossil fuels due to depletion of finite resources 7,8 , which-under many scenarios-remain the dominant energy source to at least 2050 9. Second, the estimated EROI ratios for renewable energy sources are often contentious, vary greatly depending on the adopted methodology, and are commonly estimated as lower than fossil fuels 10. Concerns follow that the renew-ables-led energy transition required to meet climate targets 11 may have adverse socioeconomic impacts 12. Third, EROI as a topic has become more accessible through the readily visualized concepts of a 'net energy cliff ' 8-where available net energy declines precipitously below EROI ratios of 5:1-and a minimum threshold level of societal-level EROI 13,14. However, much of the increased attention is confined to academic circles. One reason may be that fossil fuel EROI is commonly estimated at the primary (energy source) stage, where EROI ratios (that is, for oil, coal and gas) are high (typically over 25:1 (refs. 7,15)). Such ratios suggest to modellers and policymakers that EROI ratios will not fall below a threshold of concern until well into the renewables transition 12. However, this is a misleading perception, as instead, fossil fuel EROI should be estimated at the final (energy carrier) stage (for example, electricity, gas and petrol), during which energy enters the economy. This enables a fairer comparison with renewables-based EROI estimates, and a platform for improved energy and climate policy. We build on recent EROI research 10,15,16 to provide an estimate of global fossil fuel-based EROI at a final energy stage, which better matches that of renewables-based EROI. We combine national-level International Energy Agency (IEA) energy data with a multire-gional input-output (MRIO) approach to include a wider boundary of direct energy production sectors and associated indirect (sup-ply chain) energy impacts, including trade. To enable comparison with existing methods and EROI ratios, we estimate global fossil fuel EROI for both primary (EROI PRIM) and final (EROI FIN) energy stages, and provide time series estimates for the 1995-2011 period. Our results indicate that by 2011 global ratios for EROI FIN (~6:1) were much lower than for EROI PRIM (~30:1), and both are declining. Two implications follow. First, EROI of fossil fuels may be much closer to renewables than is commonly supposed, meaning that a global renewables transition may not be as biophysically troublesome as was previously thought. Second, the low and declining EROI FIN ratio for fossil fuels provides an immediate concern and also implies that we are much nearer a 'net energy cliff ' than was previously thought, where the nonlinearity of EROI means that low ratios (below 5:1) quickly restrict the net energy available to society. Global fossil fuel EROI based on a final energy stage A landmark study by Cleveland et al. 17 in the 1980s estimated EROI in the United States for fossil fuels at the 'well head' (oil and gas) and 'mine mouth' (coal). Since then, many fossil fuel EROI studies have been published 15 , although these largely remain at the primary energy stage (as coal, oil or gas). The most common exceptions are fossil fuel-based EROI estimates of electricity, which are at the final energy stage. However, their methodologies (and hence estimates) vary, with some (for example, refs. 10,15) taking primary-stage EROI estimates and applying direct (thermal) loss factors in conversion to electricity, while others (for example, ref. 18) use life cycle analysis (LCA)-based methods to include both thermal losses and supply chain energy investment. At the same time, an increasing number of studies are estimating EROI ratios for modern renewables, particularly electricity generated from photovoltaics and wind turbines, which are seen as two energy technologies pivotal to reductions in global greenhouse gas emissions 11. Under many scenarios, fossil fuels are projected to remain the dominant energy source until at least 2050. However, harder-to-reach fossil fuels require more energy to extract and, hence, are coming at an increasing 'energy cost'. Associated declines in fossil fuel energy-return-on-investment ratios at first appear of little concern, given that published estimates for oil, coal and gas are typically above 25:1. However, such ratios are measured at the primary energy stage and should instead be estimated at the final stage where energy enters the economy (for example, electricity and petrol). Here, we calculate global time series (1995-2011) energy-return-on-investment ratios for fossil fuels at both primary and final energy stages. We concur with common primary-stage estimates (~30:1), but find very low ratios at the final stage: around 6:1 and declining. This implies that fossil fuel energy-return-on-investment ratios may be much closer to those of renewables than previously expected and that they could decline precipitously in the near future. NAtuRE ENERGy | VOL 4 | JULY 2019 | 612-621 | www.nature.com/natureenergy 612
2009
Economies are fueled by energy produced in excess of the amount required to drive the energy production process. Therefore any successful society's energy resources must be both abundant and exploitable with a high ratio of energy return on energy invested (EROI). Unfortunately most of the data kept on costs of oil and gas operations are in monetary, not energy, terms. Fortunately we can convert monetary values into approximate energy values by deriving energy intensities for monetary transactions from those few nations that keep both sets of data. We provide a preliminary assessment of EROI for the world's most important fuels, oil and gas, based on time series of global production and estimates of energy inputs derived from monetary expenditures for all publicly traded oil and gas companies and estimates of energy intensities of those expenditures. We estimate that EROI at the wellhead was roughly 26:1 in 1992, increased to 35:1 in 1999, and then decreased to 18:1 in 2006. These trends imply that global supplies of petroleum available to do economic work are considerably less than estimates of gross reserves and that EROI is declining over time and with increased annual drilling levels. Our global estimates of EROI have a pattern similar to, but somewhat higher than, the United States, which has better data on energy costs but a more depleted resource base.
A Preliminary Investigation of Energy Return on Energy Investment for Global Oil and Gas Production
Energies, 2009
Economies are fueled by energy produced in excess of the amount required to drive the energy production process. Therefore any successful society's energy resources must be both abundant and exploitable with a high ratio of energy return on energy invested (EROI). Unfortunately most of the data kept on costs of oil and gas operations are in monetary, not energy, terms. Fortunately we can convert monetary values into approximate energy values by deriving energy intensities for monetary transactions from those few nations that keep both sets of data. We provide a preliminary assessment of EROI for the world's most important fuels, oil and gas, based on time series of global production and estimates of energy inputs derived from monetary expenditures for all publicly traded oil and gas companies and estimates of energy intensities of those expenditures. We estimate that EROI at the wellhead was roughly 26:1 in 1992, increased to 35:1 in 1999, and then decreased to 18:1 in 2006. These trends imply that global supplies of petroleum available to do economic work are considerably less than estimates of gross reserves and that EROI is declining over time and with increased annual drilling levels. Our global estimates of EROI have a pattern similar to, but somewhat higher than, the United States, which has better data on energy costs but a more depleted resource base.
EROI of different fuels and the implications for society
Energy Policy, 2014
For nations examined, the EROI for oil and gas has declined during recent decades. Lower EROI for oil may be masked by natural gas extracted/used in oil production. The EROI trend for US coal is ambiguous; the EROI for Chinese coal is declining. Renewable energies lack desirable fossil fuel traits, including often higher EROI, but create fewer pollutants. Declines in EROI of main fuels have a large impact on economies.
Introduction to Special Issue on New Studies in EROI (Energy Return on Investment)
Sustainability, 2011
Energy Return on Investment (EROI) refers to how much energy is returned from one unit of energy invested in an energy-producing activity. It is a critical parameter for understanding and ranking different fuels. There were a number of studies on EROI three decades ago but relatively little work since. Now there is a whole new interest in EROI as fuels get increasingly expensive and as we attempt to weigh alternative energies against traditional ones. This special volume brings together a whole series of high quality new studies on EROI, as well as many papers that struggle with the meaning of changing EROI and its impact on our economy. One overall conclusion is that the quality of fuels is at least as important in our assessment as is the quantity. I argue that many of the contemporary changes in our economy are related directly to changing EROI as our premium fuels are increasingly depleted.
Looking for a Silver Lining: The Possible Positives of Declining Energy Return on Investment (EROI)
Sustainability, 2011
Declining energy return on investment (EROI) of a society's available energy sources can lead to both crisis and opportunity for positive social change. The implications of declining EROI for human wellbeing are complex and open to interpretation. There are many reasons why frugal living and an energy diet could be beneficial. A measure of wellbeing or welfare gained per unit of energy expended (WROEI) is proposed. A threshold is hypothesized for the relation between energy consumption and wellbeing. The paper offers a biophysical-based social science explanation for both the negative and positive possible implications of declining EROI. Two sets of future scenarios based on environmental and economic trends are described. Six types of social change activism are considered essential if the positives of declining EROI are to balance or exceed the negatives.
2011
Declining energy return on investment (EROI) of a society's available energy sources can lead to both crisis and opportunity for positive social change. The implications of declining EROI for human wellbeing are complex and open to interpretation. There are many reasons why frugal living and an energy diet could be beneficial. A measure of wellbeing or welfare gained per unit of energy expended (WROEI) is proposed. A threshold is hypothesized for the relation between energy consumption and wellbeing. The paper offers a biophysical-based social science explanation for both the negative and positive possible implications of declining EROI. Two sets of future scenarios based on environmental and economic trends are described. Six types of social change activism are considered essential if the positives of declining EROI are to balance or exceed the negatives.