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Decarbonization of Liquid Fuels

Decarbonization of Liquid Fuels

What if the explosion of modern progress and economic growth associated with the industrial revolution depends on the massive saving of the requirements of land and labor in human affairs made possible by oil?

If we agree on this point, probably biofuels (a strategy using land and labor to save oil) are not a good idea to boost further economic growth. This Uncomfortable Knowledge Hub (UKH) series consists of one teaser video and two video lectures reflecting on the experience done in the past and on the future of biofuels in EU.

What is uncomfortable knowledge?

Uncomfortable knowledge is a concept introduced by Steve Rayner*. As Rayner puts it: “to make sense of the complexity of the world so that they can act, individuals and institutions need to develop simplified, self-consistent versions of that world”. The chosen, self-consistent narratives and explanations necessarily leave out some relevant aspects of the issue in order to remain simple and useful. In this situation “knowledge which is in tension or outright contradiction with those versions must be expunged. This is uncomfortable knowledge which is excluded from policy debates, especially when dealing with ‘wicked problems’”.

*Steve Rayner, 2012. Uncomfortable knowledge: the social construction of ignorance in science and environmental policy discourses. Economy and Society 41(1): 107-125.

What is quantitative storytelling?

Quantitative storytelling (QST), the systematic approach used to present material on the Uncomfortable Knowledge Hub, does not claim to present the “truth” about a given issue, nor that all the numbers used in the story are uncontested. When dealing with wicked issues, all numbers can always be calculated in a different way and narratives are always contested. QST simply presents alternative stories useful to check the quality of existing narratives and to enrich the diversity of insights about a given issue.


The basic problem with the idea of biofuels (2 min 22 sec)

The basic problem with the idea of biofuels. If we compare the various inputs (labor, land, water, technical capital) required to supply a net MJ of fossil fuels with the supply of a net MJ of biofuels, we can clearly see the systemic lack of biophysical feasibility and economic viability of biofuels. Current consumption of fossil fuels could not substituted by existing biofuels.

Lessons learned from the large-scale experiment of agro-biofuels in USA and Brazil in the ‘90s​ (9 min 22 sec)

What lessons can we learn from the large-scale experiment of agro-biofuels in USA and Brazil in the ‘90s? The production of ethanol from corn (in the USA) and ethanol from sugarcane (in Brazil) represents an example of two completely different approaches to the production of agro-biofuels. In the US case, they boosted labor productivity but this solution killed the net energy supply.  In the Brazilian case, they boosted the net energy supply, but this solution killed the labor productivity. The lessons learned across the two solutions suggest a central conclusion: there is something radically wrong with the idea of producing fuels from food. 

Can biofuels drive our future? A reflection on the situation of biofuels in the EU and their future​ (12 min 50 sec)

Can biofuels drive our future? The situation of biofuel in the EU is bad: the amount produced is irrelevant in relation to demand, they do not reduce emissions (when considering Indirect Effects of Land Use Changes), and they do not guarantee self-sufficiency (their production requires a significant import of feed-stocks). Possibly, the future looks even worse—the existing supply is based on typologies of biofuels that must be phased out and new generations are not looking too rosy. Acknowledging that we badly need alternatives to fossil liquid fuels does not entail that anything or everything goes. Why don’t we look for processes of generation of fuels not depending on biomass?


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Biofuels at a crossroads: the concerns are stacking up

Biofuels at a crossroads: the concerns are stacking up

Maddalena Ripa, Mario Giampietro, Juan José Cadillo Benalcazar

The International Energy Agency reports that ‘modern bioenergy is the overlooked giant within renewable energy.’ In the United States, as in many OECD countries, emissions from electricity generation are no longer the top contributor to climate change: the first position in terms of carbon emissions now belongs to cars and trucks. The Intergovernmental Panel on Climate Change (IPCC, 2018) recently reported that electricity’s involvement in the transport mix should increase to 1.2% in 2020, 5% in 2030 and 33% in 2050, meaning that by 2030 biofuel-powered vehicles would still be as important as e-cars.

Biofuels are therefore at a crossroads. In the EU28, biofuel consumption in the transport service has grown more than six fold over the last decade, however biofuels still account for just three to four percent of all transport fuel energy.  What are the concerns related to the plausibility of a fast and effective expansion of this option?

1. Around half of the EU’s production of crop biodiesels is based on imports of feedstock, not crops grown by EU farmers (Transport & Environment, 2017)

Over the years 2000-2016, the production of biofuels in EU28, especially biodiesels, has increased exponentially in EU28.  However, imports and exports associated with biofuels increased as well, especially in countries like The Netherlands. This scale-up adds another level of complexity, making it difficult to get a clear picture of the situation: to what extent is the production of biofuels in the EU aimed at lowering emissions, and to what extent is it a mechanism aimed at profiting on subsidies?  Looking at the feedstock mix, only 47% of the feedstocks were grown in the EU for EU production in 2015, meaning that over half the feedstock mix was imported (EC, DG AGRI, 2016). Evidence for this can be found in the different oils used in the EU: in 2016, according to OilWorld, 33% of EU vegetable-oil biodiesel came from imported palm oil. Rapeseed still remains the most used raw material (around 60%). This is also true for Used Cooking Oil (UCO): according to the European Commission DG AGRI Medium-Term Agricultural Outlook, 56% of raw materials used for the production of biodiesel in Europe originated from within the Union in 2015. However, this figure assumes that waste oil is all domestic, which is incorrect. Imported used oils mean it is likely that less than half of the biodiesel supply is from EU production. 

2. There is debate about whether biofuels represent a net energy supply (i.e., whether biofuels require more energy inputs in their production phase than what they provide).

The process of growing crops, manufacturing fertilizers and pesticides, and processing plants into fuel consumes a lot of energy. At the moment, most of the energy used in the various phases of production comes from oil, coal and natural gas (fossil energy). This implies that the assessment of the net energy supply of biofuels is still quite controversial. Endless discussions and a large amount of scientific publications have been dedicated to this issue.  For example, various studies have estimated the EROI (Energy Return on Investment)  of corn ethanol at between 0.8:1 and 1.7:1, meaning that we get between 0.8 and 1.7 joules of energy from ethanol for every joule of energy invested in producing that ethanol. The EROI of gasoline, by comparison, is between 5:1 and 20:1, depending in part on the source of the petroleum (Hall et al., 2011). However, the general agreement is that, when compared with the production of fossil fuels, the energetic convenience of producing biofuels is much lower, even less in case of advanced biofuel (Forbes, 2018).

3. Total life-cycle greenhouse gas emissions from biofuels are virtually impossible to measure

While ‘direct emissions’ can be lower for biofuels (if one agrees on how to calculate the net supply), the assessment of ‘indirect emissions’ are elusive.  Greenhouse gases (GHG) are emitted throughout various stages in the production and use of biofuels: in producing the fertilizers, pesticides, and fuels used in farming, during chemical processing, transport and distribution, up to final use. This process involves a significant amount of fossil energy uses along the entire supply chain that can make biofuels less environmentally friendly than petroleum-based fuels. In relation of indirect emissions, the elephant in the room is represented by the potential increase of overall GHG emissions due to indirect land-use change (ILUC) – e.g. the controversy over palm oil.  Indeed, when considering in the assessment the effects of land-use changes, the claim that biofuels do imply a reduction of emissions becomes very difficult to defend.

4. What about aviation?

Between 2005 and 2017, carbon dioxide emissions increased by 16% and nitrogen oxide emissions went up by 25%, according to the second European Aviation Environmental Report (EAER). Specific to aviation, total GHG emissions were projected to increase by 400%–600% between 2010 and 2050, based on projected growth in travel (ICAO, 2013).  In relation to the growing concern for this specific typology of liquid fuels, the potential use of biojet kerosene is very limited because of the higher cost compared with petroleum jet fuel. There are several initiatives to promote aviation biofuel, such as higher subsidies,  but…as the International Air Transport Association forecasts the 3.8 billion air travelers in 2016 to double to 7.2 by 2035,  the question arising is: is there enough land available to produce biojet fuel?

5. There isn’t adequate technological infrastructure to produce advanced biofuels in the EU

In the effort to decarbonise the transport sector, EU Member States recently decided to revise the Renewable Energy Directive (RED II) setting an obligation for Member States to ensure the achievement of 14% Renewable Energy Sources (RES) in transport by gradually phasing out crop-based biofuels (from 7% in 2020 to 3.8% in 2030) and boost 2nd and 3rd generation biofuels.  However, the production of advanced biofuels from non-food crop feedstocks is still limited. Biodiesel and HVO (Hydrotreated Vegetable Oil) from waste oil and animal fat feedstocks is around 6-8% of all biofuel output and is anticipated to remain modest in the short term, as progress is needed to improve technology readiness (IEA, 2019).

6. There is an acute lack of transparency about the biofuels used in the EU

Data about biofuels can generate confusion in relation to three main points:

  • What ‘biofuels’ are we talking about? - the label may refer to liquid fuels, biogas or wood pellets. These three different forms have very different functions – wood pellets, for example, cannot be used to power a car.  Summing up these three different energy forms into an overall estimate should be avoided because the overall number generated by summing ‘apples’ and ‘oranges’ does not have any policy relevance and muddles the discussion;
  • What 'primary source' are we talking about? - production can be based on two different processes. The first is the actual production of biomass. This type of primary source entails constraints on supply related to the availability of land, water and the ecological sink capacity for technical inputs. A second process is the valorisation of wastes. Here, we are dealing with ‘secondary sources’ leading to constraints on the supply determined by the availability and the cost of collection of the waste. Addressing this difference is essential to estimate how much the given supply of biofuels can be scaled-up when looking for a substitution of the actual consumption of oil;
  • Accounting of imports - imports of biofuels ‘energy carriers’ vs imports of feedstocks ‘primary sources’.  The emissions associated with the processes taking place in the countries generating the imported inputs are often neglected in local assessments. Moreover, double counting was included in the RED I (art. 3f) and was applied to the advanced or second-generation biofuels. Double counting means, for instance, that if molasses consumption is 2%, it will be counted as 4% of the total energy used in transport.   

With growing fuel demand in the transport sector, all these controversies surrounding biofuels should deserve attention at the science-policy interface.



European Commission, DG AGRI Medium-Term Agricultural Outlook 2016-2026

European Commission, 2016. Second European Aviation Environmental Report https://ec.europa.eu/transport/sites/transport/files/european-aviation-environmental-report-2016-72dpi.pdf

Forbes, 2018. The Ethanol Debate Matters, But Is Unlikely To Change. https://www.forbes.com/sites/joshuarhodes/2018/02/25/the-ethanol-debate-matters-but-is-unlikely-to-change/#648485c65e26

Hall C., Dale B. and Pimentel D., 2011. Seeking to Understand the Reasons for Different Energy Return on Investment (EROI) Estimates for Biofuels. Sustainability 3: 2413-2432 doi:10.3390/su3122413. 

International Energy Agency, 2019. Biofuels for transport. Tracking Clean Energy Progress https://www.iea.org/tcep/transport/biofuels/

International Civil Aviation Organization (ICAO), 2013. Environmental Report: Destination Green.

IPCC, 2018: Global warming of 1.5°C. An IPCC Special Report on the impacts of global warming of 1.5°C above pre-industrial levels and related global greenhouse gas emission pathways, in the context of strengthening the global response to the threat of climate change, sustainable development, and efforts to eradicate poverty [V. Masson-Delmotte, P. Zhai, H. O. Pörtner, D. Roberts, J. Skea, P.R. Shukla, A. Pirani, W. Moufouma-Okia, C. Péan, R. Pidcock, S. Connors, J. B. R. Matthews, Y. Chen, X. Zhou, M. I. Gomis, E. Lonnoy, T. Maycock, M. Tignor, T. Waterfield (eds.)].

Transport & Environment, 2017. Reality check - 10 things you didn’t know about EU biofuels policy. https://www.transportenvironment.org/publications/reality-check-10-things-you-didn%E2%80%99t-know-about-eu-biofuels-policy

The energetic convenience is commonly intended as EROI (Energy Return On Investment) which is the energy returned from an activity compared to the energy invested in that process. The basic equation is: EROI = Energy gained from an activity/Energy used in that activity. Any time the EROI is less than 1:1, it takes more energy to produce the fuel than the fuel contains.

The biofuel promise: examining sustainability and policy expectations around liquid biofuels

31 December 2019

The biofuel promise: examining sustainability and policy expectations around liquid biofuels

Maddalena Ripa

Biofuels represent a ‘wicked problem’ (i.e. a problem characterized by a diversity of conflicting values at stake and associated with high uncertainties) and have triggered sharply contested views in the policy arena. The heterogeneous methods used to measure compliance of biofuels with sustainability criteria, as well as the changing regulatory frameworks and moving targets have created a substantial confusion.

In MAGIC, biofuels have been framed both as a technological innovation—referring to the sustainable use of biomass to produce energy (mostly fuels)—and as a promise, providing a way out of the nexus policy impasse.

First, biofuels are framed as innovations potentially offering win-win solutions to the double problem of reducing the consumption of fossil fuels (to improve energy security and/or mitigate climate change) and supporting economic growth (and all the activities dependent on liquid fuels that cannot run on electricity). Over the last twenty years, several assessment methods have been employed to investigate biofuels from a sustainability viewpoint, such as energy analyses, life cycle assessment, carbon and water footprints (Azadi et al., 2017). These approaches, however, are usually based on just one or a limited set of indicators (e.g. GHG emissions and energy efficiency) that can be reduced to a single index (UNEP, 2017). Even when a larger set of indicators are provided, the protocol of analysis dislocates these indicators from any specific context (Bridge, 2001; Levidow, 2013). For example, questions of uneven spatial distribution in terms of where biomass has come from, which regions have borne the negative impacts, which ones benefited, and alternative techniques of production are not typically included in ‘sustainability assessment’. As a result of the lack of a more holistic picture and despite a large amount of studies, controversy has historically surrounded the assessment of the sustainability of biofuels and uncertainty has been growing in relation to their possible benefits and risks.

In MAGIC, we developed an analytical framework to characterize and contextualize in quantitative terms the performance of biofuel systems (see Ripa et al. 2020). This framework derives from the integration of three scientific fields—energetics (Ostwald, 1907), relational analysis (Rosen, 2005), and the flow-fund model of Georgescu-Roegen  (Georgescu-Roege, 1975)—and helps to tame the confusion about the performance of biofuels. Figure 1 presents the four relevant perspectives on biofuels of the proposed framework:

  1. The social factors determining their requirement on the demand side—why do we want to produce biofuels?
  2. The internal technical and economic constraints affecting their mode of production on the supply side—how can we produce biofuels?
  3. The external biophysical constraints limiting their production—what are the material limits imposed by the availability of natural resources?
  4. The level of openness of the biofuel system referring to imports being specifically used to overcome local limits (thus externalizing the requirement of natural resources and technical production factors).


Figure 1. The relations over the factors relevant for studying the feasibility, viability, desirability and level of openness (externalization) of biofuel systems. Source: Ripa et al. (2020).


The framework aims to check the quality of energy strategies in terms of desirability, viability and feasibility by comparing the technical characteristics of the energy supply system against the specific characteristics of the social-ecological systems expected to use them (Figure 2). Therefore, this analytical framework enhances the diversity of the quantitative information used in the process of decision-making. Rather than looking for the ‘best course of action’ or ‘optimal solution’ in relation to technical processes described “in general” and out of context, our approach allows a special tailoring of the definition of both the purpose of the analysis and the resulting characterization of performance.


Figure 2. The characteristics of the metabolic node – the supply reflecting the characteristics of the material-formal-efficient cause) vs the characteristics of the metabolic niche – the demand reflecting the characteristics of the efficient-final cause. 


The second framing used in MAGIC is that of biofuels as a promise. In this case, what matters is the idea of biofuels as an environmentally-friendly and renewable way of producing fuels. The EU has consistently supported biofuels, despite controversies, criticisms and even discontinuities in political support. Hence, in this analysis we examined why some ‘solutions’ persist, even when they have persistently failed once materialized.

Our results show that, in spite of scientific criticisms regarding the viability of biofuels, the European Commission has maintained its support for their development through a continuous adjustment of expectations (i.e. why producing biofuels) - energy security, reduction of GHG emissions, employment in agriculture, improvement of fuel quality, contribution to the circular economy and avoidance of sunk costs to investors - and targets in the various policies regarding biofuels (Cadillo-Benalcazar et al. 2020). Our analysis challenges the plausibility of biofuels’ policies and concludes that, depending on their specific legitimate perspectives, social actors may first identify a convenient target to set (or preserve) and then select a fitting justification (from among the many possible ones) to support that target. Therefore, achieving biofuel targets has become a justification in itself (Cadillo-Benalcazar et al. 2020).



Azadi, P., Malina, R., Barrett, S.R.H., Kraft, M., 2017. The evolution of the biofuel science. Renew. Sustain. Energy Rev. https://doi.org/10.1016/j.rser.2016.11.181

Bridge, G., 2001. Resource Triumphalism: Postindustrial Narratives of Primary Commodity Production. Environ. Plan. A Econ. Sp. 33, 2149–2173. https://doi.org/10.1068/a33190

Cadillo-Benalcazar, J., Bukkens, S.G.F., Ripa, M., Giampietro, M., 2020. Quantitative story-telling reveals inconsistencies in the European Union’s biofuels policy. Energy Res. Soc. Sci. Under Review.

Georgescu-Roege, N., 1975. Energy and Economic Myths. South. Econ. J. https://doi.org/http://dx.doi.org/10.2307/1056148

Levidow, L., 2013. EU criteria for sustainable biofuels: Accounting for carbon, depoliticising plunder. Geoforum 44, 211–223. https://doi.org/10.1016/j.geoforum.2012.09.005

Ostwald, W., 1907. The modern theory of energetics. Monist 17, 481–515. https://doi.org/doi.org/10.5840/monist190717424

Ripa, M., Cadillo-Benalcazar, J.J., Giampietro, M., 2020. Cutting through the biofuel confusion: an analytical framework to check the feasibility, viability and desirability of biofuels. Energy Strategy. Under Review.

Rosen, R., 2005. Life itself: a comprehensive inquiry into the nature, origin, and fabrication of life. Columbia University Press, New York.

UNEP, 2017. Assessing Biofuels. Towards Sustainable Production and Use of Resources.