Final Report Summary - POPFULL (System analysis of a bio-energy plantation: full greenhouse gas balance and energy accounting) The recent 2030 Framework for Climate and Energy Policies requires that by 2030 the EU will have reduced its domestic greenhouse gas emissions by 40% and increased renewable energy to be at least 27% of the total energy mix. Bioenergy from solid biomass energy crops is the most promising option as a renewable energy source. By substituting fossil fuels, biomass energy crops help to reduce anthropogenic greenhouse gas emissions. They produce decentralised green electricity and heat for local consumers and, because the biomass can be stored, complement other intermittent renewable energy sources such as wind and solar power. Three main questions, however, need to be answered before a conclusive assessment can be made of the efficacy of bioenergy as a viable renewable energy source with potential for carbon mitigation: - Question 1: Is bioenergy from woody biomass energy efficient? In other words: how does its energy balance look like?- Question 2: Does bioenergy present a favourable greenhouse gas balance, in other words will bioenergy be helpful for climate change mitigation? - Question 3: Is bioenergy from woody biomass economically profitable? The POPFULL project – titled: ‘System analysis of a bioenergy plantation: full greenhouse gas balance and energy accounting’; http://uahost.uantwerpen.be/popfull – has provided conclusive answers to these three questions. In a world-first research the project has produced the thusfar only complete cradle-to-grave analysis of a renewable bioenergy source. The largest operational bioenergy plantation in the Benelux countries was first established in the spring of 2010. Then, over five years (2010-2014) a novel approach has been applied, managing the plantation of fast-growing poplar and willow trees as a short-rotation coppice in two-year rotation cycles. After each rotation the plantation was harvested and the coppice left to regrow as a multi-stem culture. The POPFULL project intensively monitored the plantation from establishment through to the production of bioenergy in combined heat-and-power plants. For this highly ambitious analysis of the entire bioenergy production chain an international, multi-disciplinary team of 12 full-time researchers and technicians was brought together.The low-input short rotation coppice was a success: each year it supplied 10 tonnes of dry wood chips per ha to decentralised bioenergy plant operators in Belgium. In answer to Question 1 the energy efficiency was calculated by monitoring all energy inputs and outputs, and comparing it with the amount of renewable electricity and heat produced. The bioenergy production was highly energy efficient, yielding eight times more energy than was put in. With a very positive energy balance the 18 ha plantation provided enough energy to annually supply 50 average households with renewable electricity. To answer Question 2, the net fluxes of the five principal greenhouse gases between the plantation and the atmosphere were continuously monitored from a meteorological mast in the field. The plantation was a net carbon sink, i.e. absorbed more carbon from the atmosphere than was produced. But the non-CO2 greenhouse gases (methane and nitrous oxide) represented an overall net emission to the atmosphere. Direct land-use change and harvesting were the principal contributors to the total greenhouse gas emissions of the plantation. Although the plantation was a small net producer of greenhouse gases, the electricity and green heat from bioenergy reduced greenhouse gas emissions by 78% as compared to electricity from fossil fuel generators in the EU. In answer to Question 3 the POPFULL project showed that the bioenergy culture was not economically viable. The total cost of producing bioenergy was five times higher than the benefit of the renewable energy produced. Profit can only be made from bioenergy if the land is owned by the producer and if the biomass plantation is (at least partly) subsidized over its 20-year lifetime. Another drawback for the implementation is the substantial amount of land area required for the energy production (1 m2 per kWh). The unique results of the POPFULL project were presented by National Geographic who produced an entire documentary on POPFULL (http://behindthescience.uantwerpen.be/eng/renewable_energy/episode) in April 2013. The results illustrate the potential of bioenergy from woody biomass, but also highlight that a number of restrictions still need to be removed. The outcome of the project also delivers a blue-print or framework for future eco-balance analyses of other bioenergy production systems.
