Fact or Fiction: Bioenergy and Climate Change

When discussing energy and climate, we are confronted with a wide range of misconceptions that often elicit conflicting responses. With this FAQ focused on bioenergy, Carbone 4 aims to shed light on the debate and separate fact from fiction by offering a scientific, data-driven analysis of each common misconception.

To learn everything there is to know about energy and climate, check out the other FAQs available

Don't bioenergy sources emit greenhouse gases?

The bioenergy (wood, biogas, liquid biofuels) are very often considered “low-carbon”by default. However, the reality is more nuanced.

In the best-case scenario (green), the bioenergy are all lower-carbon than their fossil fuel alternatives (in blue).

But they are so by convention. In fact, it is believed that this organic matter has sequestered (and will sequester after replanting for the next cycle) the same amount of carbon^[1] than that emitted by their combustion.

In reality, the low-carbon nature depends on the nature and origin of the incoming material (forestry and agricultural practices), and can quickly be called into question (orange).

• As for the wood, if it comes from a unhealthy forest no longer sequestering carbon (which is the case in certain regions of France^[2]), carbon content 1 kWh can range from 200 to 450 gCO2e.
• In Europe, as early as 2013, the share of biofuels was limited because of the environmental impact associated with the deforestation in South American and Asian countries had been singled out. The biodiesel could then be quite higher in carbon than its fossil fuel equivalent, due to imported deforestation.

Is competition between biofuels and food production extremely significant?

In France, 4% of agricultural land is used for biofuel production. In addition, imports—mainly from Europe and the Americas—account for approximately twice that amount.

For these retail spaces, competition is fierce with the food sector: About 75% of the crops grown in France are food crops like beets.

As things stand, Increasing consumption would intensify this competition, the greatest risk of which is imported deforestation. This additional demand could potentially be met by imports resulting directly from deforestation or, indirectly, by shifting French crops—now grown for biofuels—to agricultural land linked to deforestation. And If deforestation occurs, the decarbonization benefits of biofuels are lost^[3] or even turn negative.

However, European regulations provide a framework for managing this risk. First, it limits the volume of biofuels blended into gasoline and diesel sold at the pump. In 2015, the European Union capped the energy share of conventional biofuels—produced from grains and other starch-rich, sugar-rich, and oil-rich crops grown on agricultural land (wheat, sugar beets, canola, etc.) in the transportation sector. It also restricts the import of certain products strongly linked to the risk of deforestation; notably, the RED II Directive calls for the phased-out of biofuels produced from palm oil and soybean oil by December 31, 2030. Some Member States have already excluded palm oil from the list of eligible feedstocks for biofuel production, such as France in 2020 and Germany in 2023. France also excluded soybean oil in 2022.

Is converting coal-fired power plants to biomass the way of the future?

In France and around the world, projects are emerging to give coal-fired power plants a second life by switching to biomass.

There are numerous advantages: existing footprint and industrial sites (requiring only “simple” modifications), connections to existing utility networks, and the low-carbon nature of wood combustion^[4], preservation and conversion of existing jobs, etc.

Nevertheless, this conversion has a major limitation. For example, generating 500 GWh of electricity per year using a coal-fired power plant converted to wood (the equivalent of one month’s output from a 900 MW nuclear reactor), divides by 6 theCO2 emissions (if the supply is sustainable^[5]) but doubles thefuel tonnage because wood has a lower energy density than coal.

The 354,000 metric tons of wood The resources required each year for this 500 GWh of electricity generation represent a a forest area used for timber supply that is 20 times the size of the Fontainebleau Forest.

With regard to the stability of the power grid in a future where there would be more variable electricity (particularly solar and wind power), RTE (the electricity transmission system operator) does not consider this type of conversion to be essential^[6].

When considering the energy system as a whole, the existing alternatives and this, against the backdrop of growing pressure on timber resources^[7], the relevance of this type of This conversion really does seem to warrant further examination in terms of the volume of wood consumed.

Is heating our buildings with wood a good idea for the climate?

In France, 46% of homes are still heated directly with fossil fuels (36% natural gas and 10% fuel oil or LPG, in 2021)^[8].

As a replacement, wood-burning heating is often touted because, if it comes from sustainably managed forests, it reduces emissions by about 90% compared to fossil fuels^[9]. It should be noted that this heating method is currently used in 11% of homes in France.

Does that mean we should install new wood-burning heating systems in our homes? Residential heating requires relatively low temperatures—below 100°C—which can be achieved using non-combustion technologies, whereas wood is a limited and valuable resource in several respects:

• It sequesters carbon (natural forest wells, wood construction)
• It allows for high temperatures to be reached required by certain sectors (high-temperature industrial heat)
• It is used as a raw material (paper/cardboard packaging, furniture)
• It would make it possible to produce a little bit of biofuel for aviation or the maritime that still have few mature decarbonization strategies

In addition to that, the public health issue because burning wood releases large amounts of fine particulate matter. Installing more efficient closed-hearth systems helps mitigate this effect.

In conclusion, When installing new heating systems, prioritize alternative technologies (heat pump, geothermal energy, solar thermal, connection to a carbon-free district heating network) helps preserve our forests and their resources for the ecological transition in other sectors.

Can bioenergy replace fossil fuels?

Let's take a closer look at biofuels and renewable gas, which account for a small share of the transportation mix and gas, 8% and 2%, respectively, in 2022. Can they nevertheless play a significant role in Future mixes In France? Assuming the same level of consumption, the answer is no. Reducing consumption, through energy conservation and energy efficiency, remains a priority.

As for biofuels, by 2050 in France, even in a theoretical maximum production capacity^[10], current transportation demand could be powered by biofuels at only 20%. Two measures will be necessary to ensure a balance between supply and demand: reducing consumption (e.g., shorter travel distances, the rise of active transportation, lighter vehicles) and widespread electrification.

The situation is the same for natural gas. By 2050 in France, The theoretical maximum supply of renewable gas could reach between 30% and 40% of current consumption, which implies a a 27-fold increase in current production. Once again, the reduction in consumption gas-related applications (building insulation or optimization of industrial processes) and electrification some processes are two essential conditions to help ensure a balance between supply and demand by 2050.

Will there be enough wood fuel, biofuels, and biogas for everyone?

Wood energy, biofuels, and biogas are renewable resources available in limited quantities. The work of the SNBC^[11] highlight supply constraints in meeting rising demand starting in 2030. In this context, Biomass will not be available for all uses,It is therefore necessary to prioritize.

There is no set hierarchy set in stone that all economic stakeholders agree on. However, some common trends do emerge.

The first one is the pressing need to reduce energy and material consumption through energy conservation and energy efficiency. Once consumption has been reduced to the appropriate level, a preliminary hierarchy can be considered. Food needs, followed by material needs, must remain a higher priority than energy use. These needs must be met while enriching agricultural soils and forests with carbon.

Within the energy sector, Electricity generation and the transportation sector are not priorities in most cases where alternatives exist. For the heat generation, we must prioritize the Waste Heat Recovery and Renewable Energy (geothermal energy, solar thermal energy, heat pumps), by integrating them into community distribution solutions (district heating systems or building-level systems) where applicable.