Is wood pellet-based electricity less carbon-intensive than coal-based electricity? It depends on perspectives, baselines, feedstocks, and forest management practices
P Dwivedi, M Khanna, and Madisen Fuller
Some studies suggest that the carbon intensity of electricity generated in the United Kingdom by using imported wood pellets from the southern United States is higher than that of coal-based electricity, whereas other studies suggest that the use of wood pellet-based electricity reduces carbon emissions significantly, relative to coal-based electricity. We developed the Forest Bioenergy Carbon Accounting Model (ForBioCAM 1.0) to analyze factors that influence the carbon intensity of wood pellet-based electricity, using a common set of assumptions and the same system boundary. We show that widely differing assessments of the carbon intensity of wood pellet-based electricity depend on the choice of forest management perspectives (landscape or stand), baselines (no harvest, or harvesting for the manufacture of traditional finished wood products), feedstocks (whole trees, pulpwood, or logging residues), forest management practices (change in rotation age), and the duration of the analysis itself. Unlike with a stand perspective, we demonstrate conditions under which a landscape perspective results in carbon savings net of avoided emissions from coal-based electricity. Our results also suggest that the two perspectives of forest management converge in their assessment of the positive carbon effects of various feedstock types used to manufacture wood pellets relative to a no-harvest baseline, and that the use of whole trees for wood pellets results in net carbon savings after a break-even period of about three years relative to a no-harvest scenario. The results of this study can guide future policy deliberations on the use of wood pellets as a renewable energy source worldwide.
By Mike Gaworecki
New research provides yet more evidence that granting indigenous and other local communities formal title to their traditional lands can be a boon to efforts to conserve forests.
Deforestation is responsible for as much as 10 percent of total global carbon emissions, which means that finding effective means of keeping forests standing is crucial to global efforts to halt climate change.
Previous studies have found that securing indigenous land rights is a successful path to keeping forests and the carbon sinks they represent intact. A 2016 analysis by the World Resources Institute (WRI) focused on Bolivia, Brazil, and Colombia, for instance, determined that tenure-secure indigenous forestlands could help avoid the release of carbon emissions equivalent to taking nine to 12 million passenger vehicles off the road over the next 20 years.
According to another report released last year as part of a collaborative research project by the Woods Hole Research Center, the Rights and Resources Initiative, and WRI, there is a lot of carbon stored on indigenous lands, making increased land titling a significant opportunity for climate mitigation. But the research found that, while indigenous peoples and other local forest communities manage at least 24 percent of the carbon stored above-ground in Earth’s tropical forests, or some 54,546 million metric tons of carbon (MtC), more than 22,000 MtC of that is at risk of deforestation or degradation because it is found in regions where the local communities do not enjoy formal recognition of their claim to the land.
A more recent study not only found that well-trained indigenous technicians are every bit as capable of collecting the necessary data to monitor forest carbon stocks as professionals, but that in some cases, at least, they can do it quicker and cheaper than the professionals.
The efficacy of land titling as a forest protection measure are less clear, however. But now the authors of a study published in the Proceedings of the National Academy of Sciences (PNAS) last week say they found that forest clearance is actually reduced by more than three-quarters and forest disturbance by roughly two-thirds over the two-year time span immediately following the granting of land title to an indigenous community.
VTT Technical Research Centre of Finland Ltd, the leading research and technology company in the Nordic countries, is seeking a carbon capture technology for Finnish power and heat production plants. The first pilots were implemented, using wood pellets, at VTT’s Bioruukki and the results are promising.
Finland is well on its way to achieving the 2020 climate goals, but it is already clear that the goals for 2050 are impossible to attain without major changes in energy production and other industries.
VTT has calculated that Carbon Capture and Storage (CCS) could cost-effectively cover one third of Finland’s share of reductions in greenhouse gas emissions by 2050. More than 80 per cent of carbon capture measures would concern the burning or refining biomass, and the rest would concern the coal-intensive industry. Biomass is a renewable natural fuel that binds carbon dioxide from the atmosphere as it grows. If the carbon dioxide generated by burning of biomass is captured and permanently stored deep in bedrock, carbon dioxide can be removed from the atmosphere.
Chemical Looping Combustion (CLC) is a promising carbon capture technology suitable for new plants. This technology produces flue gas that consists of carbon dioxide and water vapour as a by-product. Since the gas contains no nitrogen, carbon dioxide is easy to separate and capture – unlike in alternative technologies. Biomass burning with the help of the CLC technology (Bio-CLC) is a new research area, and VTT’s experiments in the sector are pioneering on a global scale.
The California legislature has passed legislation that aims, in part, to support existing biomass plants within the state. The bill, SB 859, features an expenditure plan for unallocated cap-and-trade proceeds.