EEA: More bioenergy crops needed for more efficiency

A broader mix of bioenergy crops to reduce environmental impacts is suggested in last report issued by the European Environment Agency (EEA).

Building on previous analysis, the report shows that the current energy crop mix is not favorable to the environment. Monocultures of cereal for example would require more rotations and a more sustainable approach that many bioenergy crops could offer. The report recommends a broader mix of bioenergy crops to reduce environmental impacts. Specifically, this should include perennial crops, which are not harvested annually – for example perennial energy grasses or short rotation plantations. In more semiarid lands, C3 grasses and C4 grasses are also suggested as more beneficial alternatives.

This would enhance, rather than harm, ‘ecosystem services’ provided by farmland – such as flood prevention and water filtration.

The analysis advocates for a broader mix of bioenergy crops, including a larger share of perennial crops. The EEA points out that perennial crops, such as energy grasses and short-rotation willow, lead to greater environmental benefit. The EEA’s report also stresses that using organic waste and agricultural or forestry residues to produce energy increases resource efficiency and results in very high GHG savings.

“The report develops three different ‘storylines’ with varying technological, economic and policy assumptions. This helps explore different future options, illustrating which bioenergy types are most resource-efficient and which have the lowest environmental impact. The main conclusions of this analysis are below:

•The EEA has revised its estimate of potential bioenergy production in the EU first published in 2006, reducing the estimate by approximately 40 %. The estimate was revised due to changes in scientific understanding, the changed EU policy framework and accounting for economic factors.
•Different biomass-to-energy conversion technologies vary significantly in their efficiency. For example, generating electricity by burning pure biomass is only approximately 30-35 % efficient, while burning the same material to produce heat is usually more than 85 % efficient. In general, using bioenergy for heat and power is a considerably more efficient way of reducing greenhouse gas emissions, compared to using bioenergy for transport fuel.
•Different energy cropping systems can vary hugely in their productivity, as well as in environmental impacts. High-yielding systems with efficient conversion can deliver more than 20 times more energy compared to low-yielding inefficient systems using the same land area.
•Current EU bioenergy policy only partially accounts for potentially adverse environmental effects connected to direct land‑use effects, including changes in land management. Additional policies could help reduce these environmental impacts, particularly regarding water resources and farmland biodiversity.
•The countries with the largest estimated agricultural bioenergy potential in 2020 are France, Germany, Spain, Italy, Poland and Romania, the report says.
•Extensively using mature trees for energy purposes may have a negative effect on the climate, due to the long time it takes for the trees to regrow and re-capture the CO2 that is released when wood is used for energy. This ‘carbon debt’ does not arise if bioenergy uses other forest biomass instead, for example branches left over from forest harvesting by-products or waste products from timber and paper production.
•Using organic waste and agricultural or forestry residues as feedstock is more resource efficient than many other types of feedstock, as it does not add pressure on land and water resources and offers very high greenhouse gas savings.”

EEA report can be download here.