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- Cintas Sanchez, Olivia, 1982, et al.
(författare)
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Carbon balances of bioenergy systems using biomass from forests managed with long rotations: bridging the gap between stand and landscape assessments
- 2017
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Ingår i: GCB Bioenergy. - : Wiley. - 1757-1707 .- 1757-1693. ; 9:7, s. 1238-1251
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Tidskriftsartikel (refereegranskat)abstract
- Studies report different findings concerning the climate benefits of bioenergy, in part due to varying scope and use of different approaches to define spatial and temporal system boundaries. We quantify carbon balances for bioenergy systems that use biomass from forests managed with long rotations, employing different approaches and boundary conditions. Two approaches to represent landscapes and quantify their carbon balances - expanding vs. constant spatial boundaries - are compared. We show that for a conceptual forest landscape, constructed by combining a series of time-shifted forest stands, the two approaches sometimes yield different results. We argue that the approach that uses constant spatial boundaries is preferable because it captures all carbon flows in the landscape throughout the accounting period. The approach that uses expanding system boundaries fails to accurately describe the carbon fluxes in the landscape due to incomplete coverage of carbon flows and influence of the stand-level dynamics, which in turn arise from the way temporal system boundaries are defined on the stand level. Modelling of profit-driven forest management using location-specific forest data shows that the implications for carbon balance of management changes across the landscape ( which are partly neglected when expanding system boundaries are used) depend on many factors such as forest structure and forest owners' expectations of market development for bioenergy and other wood products. Assessments should not consider forest-based bioenergy in isolation but should ideally consider all forest products and how forest management planning as a whole is affected by bioenergy incentives - and how this in turn affects carbon balances in forest landscapes and forest product pools. Due to uncertainties, we modelled several alternative scenarios for forest products markets. We recommend that future work consider alternative scenarios for other critical factors, such as policy options and energy technology pathways.
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- Cintas Sanchez, Olivia, 1982, et al.
(författare)
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THE CLIMATE BENEFITS OF INCREASED FOREST BIOENERGY USE IN SWEDEN: EVALUATION AT DIFFERENT SCALES
- 2014
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Ingår i: World Bioenergy 2014 Proceedings. ; , s. 133-139
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Konferensbidrag (refereegranskat)abstract
- Forest bioenergy has gained attention as an alternative to replace fossil fuels and mitigate climate change; however, in recent years its climate benefit has been questioned. The aim of this paper is to (i) present results from an assessment of the carbon (C) balance for Swedish bioenergy systems that use forest biomass from long-rotation forestry as feedstock; (ii) show how methodological choices and assumptions influence the outcome of the assessment; and (iii) discuss the climate effect of increasing forest harvest for energy use in Sweden. To achieve this purpose, an assessment framework is developed which consists of two linked models: the first one is the Q model, used to quantify the biogenic C balances associated with forest management and the second one is the CAfBio, used to account for forest product flows up to the point when the C is released into the atmosphere. Modeling results depend on many factors, with some important ones being harvest intensity, changes in forest management and the emissions intensity of the baseline scenario, which determines the C savings from using forest products. However, the results of the study support the conclusion that increased use of forest biomass for bioenergy can deliver substantial C savings.
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- Cintas Sanchez, Olivia, 1982, et al.
(författare)
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The climate effect of increased forest bioenergy use in Sweden: evaluation at different spatial and temporal scales
- 2016
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Ingår i: Wiley Interdisciplinary Reviews: Energy and Environment. - : Wiley. - 2041-8396 .- 2041-840X. ; 5:3, s. 351-369
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Tidskriftsartikel (refereegranskat)abstract
- Bioenergy from boreal forests managed for productive purposes (e.g., pulp, timber) is commonly held to offer attractive options for climate change mitigation. However, this view has been challenged in recent years. Carbon balances, cumulative radiative forcing, and average global temperature change have been calculated for a variety of bioenergy management regimes in Swedish forests and the results support the view that an increased use of forest biomass for energy in Sweden can contribute to climate change mitigation, although methodological (e.g. spatial scales) and parameter value choices influence the results significantly. We show that the climate effect of forest-based bioenergy depends on the forest ecosystems and management, including biomass extraction for bioenergy and other products, and how this management changes in response to anticipated market demands; and on the energy system effects, which determine the fossil carbon displacement and other greenhouse gas (GHG) mitigation effects of using forest biomass for bioenergy and other purposes. The public and private sectors are advised to consider information from comprehensive analyses that provide insights about energy and forest systems in the context of evolving forest product markets, alternative policy options, and energy technology pathways in their decision-making processes.
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- Amatayakul, Wathanyu, 1975, et al.
(författare)
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Determining factor for the development of CDM biomass power projects
- 2012
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Ingår i: Energy for Sustainable Development. - : Elsevier BV. - 2352-4669 .- 0973-0826. ; 16:2, s. 197-203
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Tidskriftsartikel (refereegranskat)abstract
- In this paper, a hypothesis that government's guarantee of power purchase rather than guarantee of carbon credit purchase determines the development of CDM biomass power projects in developing countries is tested by an empirical analysis using objective indicators and by an econometric analysis. The empirical analysis shows that there are indications that guarantee of power purchase rather than guarantee of access to sell carbon credits or guarantee of carbon credit purchase determines the development of a large percentage of registered CDM bagasse power projects in Brazil, India and Thailand. The result from the econometric analysis supports the hypothesis. The result also suggests that power purchase guarantee significantly determines whether or not there is development of a CDM biomass power project based on agricultural residues in a country. This suggests that implementing policies and regulations that guarantee an access for biomass power developers to sell electricity to the grid at an attractive price could lead to the development of biomass power projects in a larger number of developing countries.
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- Amatayakul, Wathanyu, 1975, et al.
(författare)
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Fuel ethanol program in Thailand: energy, agricultural, and environmental trade-offs and prospects for CO2 abatement
- 2007
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Ingår i: Energy for Sustainable Development. - 2352-4669 .- 0973-0826. ; 11:3, s. 51-66
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Tidskriftsartikel (refereegranskat)abstract
- Thailand has established an ethanol program with a target of replacing all conventional gasoline with E10 gasohol (gasoline containing 10% by volume of ethanol) by 2012. This paper assesses the impacts of achieving the target on (1) land-use change, (2) trade balance, (3) gasoline and associated food crop self-sufficiency, and (4) GHG emissions. In addition, the abatement cost of replacing gasoline with gasohol (additional cost of supplying gasohol) and the tax revenue forgone in implementing the program are estimated. Finally, in order to obtain insights in relation to the prospects of the national program vs. project-based Clean Development Mechanism (CDM) for CO2 abatement, the ethanol program is compared with specific biofuel projects. We find that achieving the ethanol program target can lead to a significant improvement in the gasoline self-sufficiency rate (from 10 to 20%) and significantly reduce GHG emissions (corresponding to 2% of the total energy-related CO2 emissions in 2004) over the period of 2005-2012. The ethanol program can induce a significant (up to 200,000 ha in magnitude) transition from food crop production (mainly corn and rice) to cassava production for ethanol leading to a reduction in the self-sufficiency rates of associated food crops. But the crop self-sufficiency rates would still be above 100% and Thailand's agricultural sector should be able to accommodate the present program target. Whether and to what extent the program leads to an improvement in the trade balance depends substantially on fuel and agricultural prices, sources of cassava supply, and responses of refineries to decreased gasoline demand. The annual average gasoline substitution cost is estimated at 25-195 US$/tCO2e, which is high compared with the price of project-based certified emission reductions traded during 2006 but low compared with estimates of the cost of substituting biofuels for fossil fuels in Europe. The tax revenue forgone is estimated at 2-4 times the gasoline substitution cost. Thailand's ethanol program illustrates that under dynamic government support, it may not be possible to identify the additionality of CDM projects for biofuel production and blending with fossil fuels. Implementing national programs as the basis for carbon credits could avoid the issues of double-counting and also have other advantages. © 2007 International Energy Initiative, Inc.
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- Axelsson, Lisa, 1984, et al.
(författare)
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Jatropha cultivation in southern India: assessing farmers experiences
- 2012
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Ingår i: Biofuels, Bioproducts and Biorefining. - : John Wiley and Sons. - 1932-104X .- 1932-1031. ; 6:3, s. 246-256
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Tidskriftsartikel (refereegranskat)abstract
- Together with 106 farmers who started growing Jatropha (Jatropha curcas L.) in 20042006, this research sought to increase the knowledge around the real-life experience of Jatropha farming in the southern India states of Tamil Nadu and Andhra Pradesh. Launched as an alternative for diesel in India, Jatropha has been promoted as a non-edible plant that could grow on poor soils, yield oil-rich seeds for production of bio-diesel, and not compete directly with food production. Through interviews with the farmers, information was gathered regarding their socio-economic situation, the implementation and performance of their Jatropha plantations, and their reasons for continuing or discontinuing Jatropha cultivation. Results reveal that 82% of the farmers had substituted former cropland for their Jatropha cultivation. By 2010, 85% (n = 90) of the farmers who cultivated Jatropha in 2004 had stopped. Cultivating the crop did not give the economic returns the farmers anticipated, mainly due to a lack of information about the crop and its maintenance during cultivation and due to water scarcity. A majority of the farmers irrigated and applied fertilizer, and even pesticides. Many problems experienced by the farmers were due to limited knowledge about cultivating Jatropha caused by poor planning and implementation of the national Jatropha program. Extension services, subsidies, and other support were not provided as promised. The farmers who continued cultivation had means of income other than Jatropha and held hopes of a future Jatropha market. The lack of market structures, such as purchase agreements and buyers, as well as a low retail price for the seeds, were frequently stated as barriers to Jatropha cultivation. For Jatropha biodiesel to perform well, efforts are needed to improve yield levels and stability through genetic improvements and drought tolerance, as well as agriculture extension services to support adoption of the crop. Government programs will -probably be more effective if implementing biodiesel production is conjoined with stimulating the demand for Jatropha biodiesel. To avoid food-biofuel competition, additional measures may be needed such as land-use restrictions for Jatropha producers and taxes on biofuels or biofuel feedstocks to improve the competitiveness of the food sector compared to the bioenergy sector.
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