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Why it is so difficult to measure biofuel emissions

Why it is so difficult to measure biofuel emissions

Bunyod Holmatov

People’s use of energy around the world is increasing (WB, 2017). This is caused by a combination of factors such as a growing population, a higher concentration of people in urban areas and higher rates of industrialization (Johansson et al., 2012). Since the industrial revolution, most of the energy in the world has been obtained from fossil fuels that are, notably, linked to the release of greenhouse gas (GHG) emissions.

By now, there is widespread consensus among scientists that anthropogenic GHG emissions contribute to changing the climate by disrupting the planet’s inherent energy balance. Among all the sources of anthropogenic GHG emissions, energy production and use contributes the most – around two thirds (IEA, 2015), making the energy sector central to climate change discussions. Therefore, a transition is underway towards renewable energy obtained from “cleaner” sources such as the sun, wind, biomass, tides and so on.

Among different types of renewables, biofuels are of particular interest because they can emit less GHGs and make countries less dependent on oil imports and their volatile prices (Karatzos et al., 2014). In a little over two decades, between 1990 and 2014, emissions from the transport sector increased by 71% (IEA, 2016), and these emissions will continue to increase in the near future. The International Energy Agency (IEA, 2017) projects that under the current policies, emissions in the transport sector will increase by 17% between 2015 and 2040. Switching to biofuels can thus bring multiple long term benefits.

However, despite the general agreement that biofuels emit less than oil-derived fuels, the actual GHG emissions (for the same type of biofuels, i.e. bioethanol, biogasoline, etc.) may vary. The variation between studies emerges because of complexity of calculations that involve different inputs during the numerous production steps. Moreover, there is a distinction between the biofuels based on the type of feedstock. The so called “conventional” biofuels are produced using agricultural crops (i.e. sugarcane, sugar beet, etc.) while “advanced” refers to non-crop based biofuels (i.e. derived from biomass, algae, etc.; EC, 2016) that have not reached large commercial-scale production.

Calculating total GHG emissions of biofuels involves data from multiple stages of production, such as the crop cultivation (conventional biofuels) or extraction (advanced biofuels), processing, transport, and distribution. Each step can also have many sub-steps, i.e. producing “conventional” biofuels involves cultivating the crops that cover four main categories of inputs: (1) agro-chemical application; (2) field nitrous oxide emissions; (3) fossil fuel use; and (4) seeding material (Ecofys, 2010; EC, 2016). Thus, reported GHG emissions for the same type of biofuel can be different depending on where and how it was produced.

When discussing biofuels, it is important then to understand what type of biofuel is being discussed, what feedstock type, how it was produced (process route) and where. Sometimes, such as in the EU energy directive, the reported ranges also specify whether emissions of biofuels refer to “typical” GHG or “default” GHG. The former is an estimate that is typical in the EU while the latter is derived from the typical value using pre-determined factors (EC, 2016). In other words, factors such as the crop yield in Europe can be different from the specified ‘default’ crop yield.

The following examples demonstrate how biofuel type, feedstock type, and process route affect the GHG emissions of biofuels. “Conventional” bioethanol can be produced using a range of crops. Using sugar based crops such as sugar beet or sugarcane requires less processing steps because sugars are readily fermentable. This means that sugar based crops emit less GHGs than starch based crops such as maize, that require relatively more processing steps to convert them to fermentable sugars. Therefore, a typical emission of a “conventional” bioethanol produced from sugarcane is 28 g CO2eq/MJ and for sugar beet is around 31 g CO2eq/MJ. In contrast, a typical emission of maize based “conventional” bioethanol is around 49 g CO2eq/MJ (EC, 2016).

While both bioethanol and biodiesel are biofuels, biodiesel emissions are higher than bioethanol emissions. Typical GHG emissions of a sunflower based “conventional” biodiesel is around 40 g CO2eq/MJ. Using palm oil as the feedstock can increase typical emissions to 58 g CO2eq/MJ. It is important to note that the “default” GHG emissions can be even higher. For instance, palm oil based “conventional” biodiesel has a default emission of 70 g CO2eq/MJ (EC, 2016). At the same time, despite having higher emissions, biodiesel can be readily used in diesel cars whereas bioethanol has to be blended with a certain ratio of gasoline to prevent corrosion of car parts. 

“Advanced” biofuels are usually promoted for their dependence on non-crop feedstocks, while in reality, they also lead to less GHG emissions compared to “conventional” biofuels. For example, producing bioethanol from corn stover can lower emissions to 31 g CO2eq/MJ (IEA, 2013), whereas using wheat straw would typically emit 13.7 g CO2eq/MJ (EC, 2016). Similarly, using waste cooking oil to produce “advanced” biodiesel would typically emit 16 g CO2eq/MJ (EC, 2016).

In terms of process routes, they are more applicable to “advanced” biofuels than to “conventional” biofuels. The latter are produced using more established methods. In contrast, feedstock processing routes of “advanced” biofuels are still in development and their effect on GHG emissions are less clear cut. For example, converting wood residue to gasoline through the “pyrolysis” processing route can emit around 49 g CO2eq/MJ while choosing the “sugar catalysis” process only emits around 5 g CO2eq/MJ (IEA, 2013).

For practical reasons, biofuel’s GHG emissions are also compared to fossil fuel emissions to indicate the degree of emissions that can be ‘saved’ by switching to a given biofuel. To give some examples, approximately 87 grams of CO2eq emissions are emitted per MJ of oil based gasoline. In contrast, converting wood residue to gasoline can lower emissions to a range between 2 and 49 grams per MJ (depending on the process route) that translates to the GHG emission savings in the range of 98% and 43%, respectively (IEA, 2013).

In conclusion, many factors contribute to the GHG emissions of biofuels. General biofuel emissions always embody certain underlying assumptions related to the feedstock, process route, location specific conditions, etc. Addressing each and every assumption of biofuel production that can yield a certain cumulative GHG emission is challenging. Thus, from the policy making perspective, the old proverb “measure twice and cut once” is ever pertinent.


Johansson, T. B., Patwardhan, A. P., Nakićenović, N., & Gomez-Echeverri, L. (2012). Global energy assessment: toward a sustainable future. Cambridge, UK: Cambridge University Press.

Karatzos, S., McMillan, J.D., Saddler, J.N. (2014). The Potential and Challenges of Drop-in Biofuels. Paris, FR: International Energy Agency. 

EC. (2016). Proposal for a Directive of the European Parliament and of the Council: on the promotion of the use of energy from renewable sources (recast). Retrieved from: https://eur-lex.europa.eu/legal-content/EN/TXT/?uri=CELEX:52016PC0767R%2801%29

Ecofys. (2010). Annotated example of a GHG calculation using the EU Renewable Energy Directive methodology. Retrieved from: https://ec.europa.eu/energy/sites/ener/files/2010_bsc_example_ghg_calculation.pdf 

IEA. (2013). Advanced Biofuels – GHG Emissions and Energy Balances: A report to IEA Bioenergy Task 39. Retreaved from: https://www.ieabioenergy.com/wp-content/uploads/2018/02/Energy-and-GHG-Emissions-IEA-Bioenergy-T39-Report-May-2013-rev.pdf

IEA. (2015). Energy and Climate Change. Retrieved from https://www.iea.org/publications/freepublications/publication/WEO2015SpecialReportonEnergyandClimateChange.pdf

IEA. (2016). CO2 emissions from fuel combustion: highlights. Retrieved from https://emis.vito.be/sites/emis.vito.be/files/articles/3331/2016/CO2EmissionsfromFuelCombustion_Highlights_2016.pdf

IEA. (2017). World Energy Outlook 2017. Retrieved from https://www.iea.org/weo2017/

WB. (2017). Energy use (kg of oil equivalent per capita): World. Retrieved from http://data.worldbank.org/indicator/EG.USE.PCAP.KG.OE


Meeting EU biofuel targets: the devil is in the detail

25 March 2019

Meeting EU biofuel targets: the devil is in the detail

The Autonomous University of Barcelona team

Transport is one of the most unsustainable sectors in the EU: it lags behind all other sectors in terms of emission reduction, and alternatives have been tricky to find, monitor and implement. In 2016, just 3.8% of the energy consumed in the transport sector came from renewable energy sources (EUROSTAT, 2019). Electric vehicles are gaining momentum as a possible solution to sustainable transport, but so far they can only substitute road passenger vehicle, leaving a big gap for other forms of transport, such as shipping and aviation. Similar to electric vehicles, biofuels are seen as a solution to simultaneously lower emissions and lower dependence on imported oil. Following concerns over indirect land use change (ILUC), the recast renewable directive set strict criteria on the sustainability of biofuels, however they are still considered to be a central element to the sustainable transport transition. Differently from renewable electricity which is generated with local resources on the spot, and from fossil fuels that are extracted with associated environmental damage, biofuels represent a peculiar case of renewable energy, since, similar to fossil fuels, they rely on a multi-step process: first the cultivation of crops, and then their conversion to fuels, with intermediate steps depending on the type of fuel. This makes their accounting more complicated. With the EU setting rigorous sustainability targets for biofuel implementation, how can this sustainability be monitored when more than half of the feedstock used to produce biofuels in the EU is imported? (Buffet, 2017)

The fact that biofuels require multiple steps, and that steps can occur within different sectors and economic domain (first in agriculture and then in the energy sector) adds more layers to the openness of the system, and with each layer come difficulties in monitoring and accounting. Take the case of the Netherlands: between 2010 and 2015, the country quadrupled its consumption of residues of Used Cooking Oil (UCO) as a raw material to produce biodiesel. As it does not have an adequate local supply, it imported 81% of UCO, of which roughly 51% came from countries outside the EU (CE Delft, 2017). Following high impact media campaigns, it has become generally well known that palm oil production leads to biodiversity loss in Indonesia and Malaysia, a fact which led the EU to implement a strategy to reduce palm oil imports from Asian countries. However, the imports of UCO derived from palm oil are not limited, and if left unchecked a rise in UCO demand may lead to a rise in palm oil production. Another issue linked to the openness of the biofuel production chain is related to the double accounting mechanism, a political guideline included in the first EU renewable energy directive.

Following this guideline, the energy participation of certain residues of animal and vegetable origin are counted twice with respect to reaching the proposed objectives. What is problematic here is that not all countries have applied the guideline, and the difference in applicability has increased dynamics in waste trade. For example, Germany, which does not apply the double accounting mechanism, exports its animal fat waste to The Netherlands (where, in contrast, the double accounting principle is applied) (CE Delft, 2015). In addition, double accounting can lead to a "virtual" share of biofuels in the transport sector, which implies that this virtual percentage will be covered in the real world by another type of fuel, perhaps fossil fuels.

Biofuels are being pushed in the EU as a solution for increased sustainability and security of supply. They also generate a massive business: in economic terms, Charles et al., (2013) estimated that for 2011 the EU allocated between 9.3-10.7 billion euros to subsidize the use of conventional biofuels - a significant figure considering that the size of the biofuel market in the EU for that year was around 13-16 billion euros. Each EU country has varied agricultural production capabilities, and setting uniform targets across all member states may push governments to import feedstock to locally produce biofuels, or to see this as a business opportunity to import and export biofuels, like The Netherlands is doing. If the EU is serious about the sustainability of it transport fuels, it should account for all steps of the biofuel production process, and regulate the trade of primary and secondary products to avoid turning biofuels into a business opportunity with little positive impact on the environment.


Buffet, L., 2017. Realitycheck-10 things you didn’t know about EU biofuels policy.

CE Delft, 2017. Sustainable biomass and bioenergy in the Netherlands Report 2016. Delft.

CE Delft, 2015. Biofuels on the Dutch market Update: data for 2013. Delft, The Netherlands.

Charles, C., Gerasimchuk, I., Bridle, R., Moerenhout, T., Asmelash, E., Laan, T., 2013. Biofuels: At What Cost? A review of costs and benefits of EU biofuel policies. Int. Inst. Sustain. Dev.

EUROSTAT, 2019. Data base - EUROSTAT [WWW Document]. URL http://ec.europa.eu/eurostat/web/main/home (accessed 2.4.19).

Giuntoli, J., 2018. Advanced Biofuel Policies in select EU Member States: 2018 Updated.

Photo credit: United Soybean Board

Can Europe utilize bioenergy without compromising sustainability?

Can Europe utilize bioenergy without compromising sustainability?

Abigail Muscat

Humans use biomass for multiple uses, mainly as sources of food, feed for livestock, energy generation and, recently, biomaterials. With a growing global population, a shift in diets towards one based on animal-source food, and higher expected demand for bioenergy and biomaterials, the pressure on biomass and the resources needed for its production will continue to increase. These growing demands can be met by increasing biomass production, but the intensification of production is often associated with higher input agriculture, which has effects on soil and biodiversity. In the EU, the potential for increased productivity is limited as yield gaps are small. Expanding the areas for biomass production could potentially avoid the damaging effects of higher input agriculture, however this could come at the expense of natural areas of high biodiversity value. For these reasons, the expansion of areas for biomass production to meet EU demands has occurred mostly outside of the EU. In fact, the imported share of the biomass footprint in the EU has grown by 33% from 1995 to 2009. If Europe decides to achieve all the Sustainable Development Goals while minimising its need for imports, trade-offs among goals of food security, climate change mitigation and sustainability may appear.

This raises the question of how the multiple claims on biomass can be handled sustainably. Bioenergy still remains one of the major renewable energy sources, with 64% of all renewable energy in the EU-28 coming from biomass in 2016. Many potential solutions are available to avoid the competition for biomass and minimise its impacts. Solutions include using marginal lands that do not compete with food production, the use of biorefineries that produce many high-value products from few resources or making use of biomass residues that currently go to waste. Therefore the question becomes, what is the scale of the current problem and which solutions may present likely futures?

Such integrated problems and solutions will require a new kind of policy-making, as the trade-offs linked to expanding bioenergy touch upon a number of policy domains in the EU, especially the Circular Economy and Bioeconomy policies. Synergies between policies will have to be better exploited and policy-design will likely have to address consumers as much as producers. Given that the EU increasingly relies on biomass imports and on natural resources worldwide, this also has implications for the EU’s ability to meet the Sustainable Development Goals. To what degree does the EU need to take responsibility for the impacts of its material consumption?

To answer some of these questions we will assess the current situation. We will look at biorefineries processing biomass and producing a host of outputs such as fuels, feed, chemicals, materials and heat. Does Europe have enough land and water to meet its bioenergy use? Are capital and labour being displaced from elsewhere? To what degree does Europe depend on biomass from outside the EU, and is this socially desirable? Furthermore, we will ask what solutions represent likely futures and what their possible effects would be. Many biorefinery configurations are possible, generating different products and sourcing different feedstocks from different types of land. Such innovations will need a careful assessment from a range of perspectives as the innovations themselves are constantly developing.

The problem of using biomass in a resource efficient way to meet the EU’s goals has been chosen for MAGIC because it is at the crossroads of sustainability governance and the water-energy-food nexus.  It provides an excellent opportunity to discuss such a key innovation right when key EU policies, such as the Bioeconomy strategy and the Renewable Energy Directive are being re-assessed and the bioeconomy is gaining ground. Many solutions exist to address the competition for biomass but often these solutions come with their own trade-offs; for example, increasing biomass availability will be difficult in Europe and the dependency on biomass imports could worsen. Other examples include using marginal lands that don’t compete with food production, but this may interfere with other possible uses, such as nature conservation or livestock production. MAGIC will help in acting as a quality check for such solutions, to best avoid the pitfalls of being locked into incoherent policies.