Assessment of potential bioenergy from coppice forests trough the integration of remote sensing and field surveys

A spatially explicit knowledge of forest resources is essential to support the sustainable use of wood as a fuel for producing energy (firewood).This paper describes the integrated use of remotely sensed data and sample based forest inventories to derive a biomass map for coppice forest, resulted estimated potential biomass available is contrasted with local domestic consumptions at the municipality level. The test was carried out in an environmentally and socially homogeneous district of Apennine Mountains (Alto Molise, south-central Italy) coupling multispectral high resolution Landsat 7 ETM+ satellite imagery and a local forest inventory trough the application of the non-parametric estimation procedure k-Nearest Neighbours (k-NN). Several forest management scenarios were applied in order to evaluate their impact on the potential availability of firewood from coppice forests.The paper introduces data and methods used and presents the achieved results both in terms of the accuracy of the biomass map produced by k-NN and of the relationship between the potential availability and demand for firewood.These results demonstrated that k-NN is able to estimate the biomass of coppice forest in the test area with an accuracy level comparable with recent similar application of k-NN carried out in Boreal regions (RMSE of 25.6%).The application of different forest management scenarios have a significant impact on local estimated firewood balance between potential supply from coppice forests and demand for domestic consumption, depending of the scenarios the net balance changed up to 84%.     

GIS-based approach for defining bioenergy facilities location: A case study in Northern Spain based on marginal delivery costs and resources competition between facilities

This paper presents a GIS-based decision support system for selecting least-cost bioenergy locations when there is a significant variability in biomass farmgate price and when more than one bioenergy plant with a fixed capacity has to be placed in the region. The methodology tackles the resources competition problem between energy facilities through a location-allocation model based on least-cost biomass quantities. Whole system least delivery cost including intermediate bioenergy products is estimated. The methodology is based on a case study where forest wood residues (FWR) from final cuttings (FCs) are used to produce torrefied wood (TW) in two torrefaction plants (TUs) that supply a gasification unit (GU) in order to produce electricity. The provinces of Navarra, Bizkaia, Gipuzkoa, Alava, La Rioja, Cantabria and Burgos are assessed in order to find the best locations for settling down the TUs and the GU according to biomass availability, FWR and TW marginal delivery costs.     

Distribution and potential of bioenergy resources from agricultural activities in Mexico

Biomass is the most abundant and versatile form of renewable energy in the world. The bioenergy production from crop residues is compatible with both food and energy production. Currently, several technologies are available for transforming crop residues into utilizable energy such as direct combustion and fermentation. Mexico is the third largest country in LAC in terms of the cropland area and would become a central focus of attention for the production of biofuels. In this paper we examined the type, location and quantities of various crop residues in Mexico to evaluate their potential for conversion into bioenergy through combustion and fermentation. It was estimated that 75.73 million tons of dry matter was generated from 20 crops in Mexico. From this biomass, 60.13 million tons corresponds to primary crop residues mainly from corn straw, sorghum straw, tops/leaves of sugarcane and wheat straw. The generation of secondary crop residues accounted for 15.60 million tons to which sugarcane bagasse, corncobs, maguey bagasse and coffee pulp were the main contributors. The distribution of this biomass showed that several Mexican municipalities had very high by-product potentials where each municipality could have an installed capacity of 78 MW (via direct combustion) or 0.3 million m³ of bioethanol per year (via anaerobic fermentation). The identification of these municipalities where the biomass potential is high is important since it constitutes the first step towards evaluating the current biomass availability and accurately estimating the bioenergy production capacity from crop residues.     

A GIS-based methodology for highlighting fuelwood supply/demand imbalances at the local level: A case study for Central Mexico

When fuelwood is harvested at a rate exceeding natural growth and inefficient conversion technologies are used, negative environmental and socio-economic impacts, such as fuelwood shortages, natural forests degradation and net GHG emissions arise. In this study, we argue that analyzing fuelwood supply/demand spatial patterns require multi-scale approaches to effectively bridge the gap between national results with local situations. The proposed methodology is expected to help 1) focusing resources and actions on local critical situations, starting from national wide analyses and 2) estimating, within statistically robust confidence bounds, the proportion of non-renewable harvested fuelwood. Starting from a previous work, we selected a county-based fuelwood hot spot in the Central Highlands of Mexico, identified from a national wide assessment, and developed a grid-based model in order to identify single localities that face concomitant conditions of high fuelwood consumption and insufficient fuelwood resources. By means of a multi-criteria analysis (MCA), twenty localities, out of a total of 90, were identified as critical in terms of six indicators related to fuelwood use and availability of fuelwood resources. Fuelwood supply/demand balances varied among localities from ?16.2 ± 2.5 Gg y^?1 to 4.4 ± 2.6 Gg y^?1, while fractions of non-renewable fuelwood varied from 0 to 96%. These results support the idea that balances and non-renewable fuelwood fractions (mandatory inputs for Clean Development Mechanism (CDM) cookstoves projects) must be calculated on a locality by locality basis if gross under or over-estimations want to be avoided in the final carbon accounting.     

Carbon sequestration potential of forest land: Management for products and bioenergy versus preservation

A 40 year projection of potential carbon sequestration is based on USDA Forest Service Forest Inventory and Analysis (FIA) data from the state of Georgia. The objective is to compare carbon sequestration under a sustainable management strategy versus a preservation strategy. FIA plots are projected ahead in time with hotdeck matching. This matches each subject plot with another plot from the database that represents the subject plot at a future time. The matched plot sequences are used to provide input data to a harvest scheduling program to generate a management strategy for the state. The sequestration from the management strategy is compared with a preservation strategy that involves no harvesting. Harvested wood is assumed to go into products with various half life decay rates. Carbon sequestration is increased as increasing proportions go into wood for energy, which is treated like a product with an infinite half life. Therefore, the harvested carbon does not return immediately to the atmosphere. Public land and land close to cities is assumed to be unavailable, and all other private land is assumed to be accessible. The results are presented as gigatonnes of CO₂ equivalent to make them directly comparable to US annual carbon emissions. The conclusion is that forest management will sequester more above-ground carbon than preservation over a 40 year period if the wood is used for products with an average half life greater than 5 years.     

The current bioenergy production potential of semi-arid and arid regions in sub-Saharan Africa

This article assesses the current technical and economic potential of three bioenergy production systems (cassava ethanol, jatropha oil and fuelwood) in semi-arid and arid regions of eight sub-Saharan African countries. The results indicate that the availability of land for energy production ranges from 2% (1.3 Mha) of the total semi-arid and arid area in South Africa to 21% (12 Mha) in Botswana. Land availability for bioenergy production is restricted mainly by agricultural land use, but also by steep slopes and biodiversity protection. The current total technical potential for the semi-arid and arid regions of the eight countries is calculated to be approximately 300 PJ y⁻¹ for cassava ethanol production, 600 PJ y⁻¹ for jatropha biodiesel or 4000 PJ y⁻¹ for fuelwood. The analysis of economic potentials shows that in many semi-arid regions, cassava ethanol, jatropha oil and fuelwood can compete economically with the reference energy sources. However, fuelwood, jatropha oil, and cassava ethanol production costs in most arid regions of sub-Saharan Africa are often above average national market prices of gasoline, diesel, and fuelwood. Nevertheless, for example, in arid Kenya 270 PJ could be produced annually with fuelwood at production costs of less than 3 US$ GJ⁻¹. Despite high production costs, it is important to investigate and invest in sustainable bioenergy production in semi-arid and arid regions of sub-Saharan Africa because of its potential to drive rural economic and social development.     

An exposé of bioenergy and its potential and utilization in Turkey

Turkey is heavily dependent on expensive imported energy resources (oil, gas and coal) that place a big burden on the economy. Air pollution is also becoming a great environmental concern in the country. In this regard, renewable energy resources appear to be one of the most efficient and effective solutions for clean and sustainable energy development in Turkey. Turkey's renewable sources are the second largest source for energy production after coal. About two-thirds of the renewable energy produced is obtained from bioenergy, which is used to meet a variety of energy needs, including generating electricity, heating homes, fueling vehicles and providing process heat for industrial facilities. The amount of usable bioenergy potential of Turkey is approximately 17 Mtoe. This article not only presents a review of the potential and utilization of the bioenergy in Turkey but also provides some guidelines for policy makers.     

A prospective study of bioenergy use in Mexico

Bioenergy is one of the renewable energy sources that can readily replace fossil fuels, while helping to reduce greenhouse gas emissions and promoting sustainable rural development. This paper analyses the feasibility of future scenarios based on moderate and high use of biofuels in the transportation and electricity generation sectors with the aim of determining their possible impact on the Mexican energy system. Similarly, it evaluates the efficient use of biofuels in the residential sector, particularly in the rural sub-sector. In this context, three scenarios are built within a time frame that goes from 2005 to 2030. In the base scenario, fossil fuels are assumed as the dominant source of energy, whereas in the two alternative scenarios moderate and high biofuel penetration diffusion curves are constructed and discussed on the basis of their technical and economical feasibility. Simulation results indicate that the use of ethanol, biodiesel and electricity obtained from primary biomass may account for 16.17% of the total energy consumed in the high scenario for all selected sectors. CO₂ emissions reduction—including the emissions saved from the reduction in the non-sustainable use of fuelwood in the rural residential sector—is equivalent to 87.44 million tons of CO₂ and would account for 17.84% of the CO₂ emitted by electricity supply and transportation sectors when the base case and the high scenario are compared by 2030.     

Evaluating potential renewable energy resources in Poultney,Vermont: A GIS-based approach to supporting rural community energy planning

The current electricity infrastructure in the United States relies on a centralized distribution network that carries a heavy carbon footprint and is susceptible to disruption and failure. Rural communities are more susceptible to longer term interruption and should strive towards a local distributed energy model. This transition will require municipalities to engage with and seek input from community stakeholders. This paper describes a possible model for supporting rural community energy projects using a Geographic Information System (GIS), which was used to develop an inventory of energy resource potential in a rural Vermont town for biomass, wind, and solar technologies.     

Assessment of the availability of agricultural and forest residues for bioenergy production in Romania

This paper provides a resource-based assessment of availability of biomass resources for energy production in Romania, at NUTS-3 level. The estimation of available biomass includes the residues generated from crop production, pruning of vineyards and orchards, forestry operations and wood processing. The estimation of crop residue availability considers several site-specific factors such as crop yields, multi-annual yield variation, environmental constraints and competitive uses. The evaluation of agricultural residues was based on specific residue to product ratios, depending on crop type and crop yield. An estimate of pruning residues is proposed, based on current orchard and vineyard areas and specific ratios of residues. Woody biomass considers forest and forestry residues (including firewood) and wood processing by-products, taking into account the type and share of the unused part of the tree biomass and technical and economic aspects, including availability and competitive use. The amount of agricultural and forest residues available for bioenergy in Romania was estimated at 228.1 PJ on average, of which 137.1 PJ was from annual crop residues, 17.3 PJ residues from permanent crops and 73.7 PJ/year from forestry residues, firewood and wood processing by-products. The biomass availability shows large annual and spatial variations, between 135.6 and 320.0 PJ, due to the variation in crop production and forestry operations. This variation, which is even larger at the NUTS-3 level, if not properly considered may result in shortages in biomass supply in some years, when biomass is available in a lower amount than the average.     

Decentralised bioenergy systems: A review of opportunities and threats

Decentralised bioenergy systems are receiving increasing attention due to the potential ability to support local development, create local employment, and contribute to climate change mitigation. These issues, along with other bioenergy sustainability issues, are reviewed through eighteen international case studies with the objective of identifying opportunities and threats to decentralised bioenergy systems. The case studies were selected based on feedstock type, bioenergy type, production capacity, synergistic alliances, ownership structure and physical locations. This variation was used to provide a basis for evaluating opportunities and threats from different contexts. Commercial viability remains the primary concern for the sustainability of decentralised bioenergy systems. There are, however, opportunities for compounding benefits through integrating small scale decentralised bioenergy systems with other production systems. Integrated production, including closed loop models, allow waste materials from one process to be used as inputs in other production processes, and thereby increasing economic, social and environmental outcomes. Synergistic opportunities along the bioenergy production chain, which include feedstock production, bioenergy marketing and distribution could also be exploited by communities and other investors to minimise decentralised production risk.     

The potential distribution of bioenergy crops in the UK under present and future climate

We have predicted the potential distribution of 26 bioenergy crops in the UK, based on the simple model described by Tuck et al. [1]. The model has been applied at a 5 km resolution using the UKCIP02 model for scenarios at Low, Medium-Low, Medium-High and High emissions. In the analysis of the results the limitations for crop growth are assigned to elevation, temperature, high and low rainfall. Most of the crops currently grown are predicted to remain prevalent in the UK. A number of crops are suitable for introduction to the UK under a changing climate, whereas others retreat to northern parts of the UK. The greatest changes are expected in England. The simplicity of the model means that it has a relatively high uncertainty, with minor modifications to the model leading to quite different results. Nevertheless, it is well suited for identifying areas and crops that are most likely to be affected by the greatest changes. It has been noted that Miscanthus and Short Rotation Coppice (SRC) willow and poplar, which are currently regarded as highly suitable for UK conditions, may be less suited to southern areas in the future, where, for example, kenaf could have a greater potential. Further investigations are required to reduce uncertainty associated with the projections based on this simple model and to make conclusions more firmly.     

Wind energy potential in southern Sweden-Example of planning methodology

This study presents a planning model for Swedish activities in the field of wind power. Models and results of calculations of the land-based wind energy potential with the Wind Atlas Analysis and Application Programme, WA^sP, are described and analysed in a geographical information systems (GIS) called the ArcView^® GIS system. One county in southern Sweden was chosen as a case study to present the methods used. The results from that case study indicate a great wind energy potential but there are nevertheless many factors limiting that potential. The study calls for a further development of planning tools in the field. Important areas for the future are the development of knowledge in market issues, wind power technology, environmental issues, and public opinion on constructing wind turbines.     

Residential bioenergy heating: A study of consumer perceptions of improved woodstoves

Consumers’ choices play a key role for the development of biomass heating in the residential sector. The city of Oslo has granted subsidies to households who change to new, improved low-emission woodstoves. The purpose of this study is to expand the knowledge about users’ experiences and attitudes to residential biomass heating. An adapted model of the Theory of Planned Behavior was used to model households’ inclination to continue using their woodstoves for heating. More than 800 questionnaires were collected from households that recently had invested in an improved woodstove. The respondents were satisfied with the new woodstoves. The respondents also considered themselves competent to use and maintain the stove and few had problems acquiring fuelwood. Further analyses showed that the intention to continue to use the new woodstove depends on economic benefits, heating performance, perceived time and effort to operate the stove, environmental effects of heating as well as perceived subjective norm. The results imply that when marketing a modern technology for bioenergy heating, both public authorities and producers should consider issues related to the users’ perception of subjective norm, such as perceived status of using bioenergy or environmental concerns, when designing campaigns to promote the use of woodstoves.     

Co-firing—A strategy for bioenergy in Poland?

Biomass provides the largest reduction of carbon dioxide (CO₂) emission when it replaces coal, which is the dominating fuel in heat and electricity production in Poland. One means of replacing coal with biomass is to co-fire biofuels in an existing coal-fired boiler. This paper presents an analysis of the strengths and weaknesses of co-firing biofuels in Poland with respect to technical, environmental, economical and strategic considerations. This analysis shows that co-firing is technically and economically the most realistic option for using biofuels in the large pulverized fuel (PF) boilers in Poland. However, from an environmental perspective, co-firing of biofuels in large combined heat and power (CHP) plants and power plants provides only a small reduction in sulphur dioxide (SO₂) emission per unit biofuel, since these plants usually apply some form of desulphurization technology. In order to maximize the SO₂ emission reduction, biofuels should be used in district heating plants. However, co-fired combustion plants can handle disruptions in biofuel supply and are insensitive to moderate changes in fuel prices, which makes them suitable utilizers of biofuels from perennial energy crops. Co-firing could therefore play an important role in stimulating perennial crop production.     

Recent developments of biofuels/bioenergy sustainability certification: A global overview

The objective of this paper is to provide a review on the latest developments on the main initiatives and approaches for the sustainability certification for biofuels and/or bioenergy. A large number of national and international initiatives lately experienced rapid development in the view of the biofuels and bioenergy targets announced in the European Union, United States and other countries worldwide. The main certification initiatives are analysed in detail, including certification schemes for crops used as feedstock for biofuels, the various initiatives in the European Union, United States and globally, to cover biofuels and/or biofuels production and use. Finally, the possible way forward for biofuel certification is discussed. Certification has the potential to influence positively direct environmental and social impact of bioenergy production. Key recommendations to ensure sustainability of biofuels/bioenergy through certification include the need of an international approach and further harmonisation, combined with additional measures for global monitoring and control. The effects of biofuels/bioenergy production on indirect land use change (ILUC) is still very uncertain; addressing the unwanted ILUC requires sustainable land use planning and adequate monitoring tools such as remote sensing, regardless of the end-use of the product.     

Local impact of renewables on employment: Assessment methodology and case study

This paper presents an integrated method that assesses the socio-economic impact of establishing renewable energy on a regional scale, in particular on the creation of jobs. The method proposed is based on the collection, critical analysis and presentation of the results obtained using primary information sources considering the jobs created as the most direct measure of the socio-economic potential of renewable energy sources. Its design includes contributions extracted from a prior analysis of the existing assessment methods, to lessen the uncertainty of the job ratios often used in these types of analysis. The integrated method implemented has been applied to the autonomous community of Aragon (Spain) as a pilot case, through which the method has been tested and the indicators selected to analyse the socio-economic impact of renewable energy sources on the jobs created, the quality of the jobs and other factors related to the socio-economic development of a territory: technological development, per capita income, territorial development and human capital.     

Spatial assessment of the bioenergy potential of forest residues in the western province of Spain, Caceres

The present work is mainly devoted to provide a rigorous analysis on the quantification, the mapping and the management of the bioenergy potential of forest residues from the most representative forestry species of the west-central region of Spain (Cáceres).An appropriate methodological approach for the estimate of potential biomass and potential bioenergy as well as the use of GIS for data process are both crucial for the design of thermal plants and for the accurate estimate of biomass collection and transportation costs, according to the scale economy of the plant.The total forest residues in the province of Cáceres are estimated as 463 000 t y⁻¹. The availability of such major biomass potential for energy production is strongly conditioned to the inherent difficulties during the extraction process. This way, an energy potential of 139 000 toe y⁻¹ would be achieved if the above-mentioned biomass collection rate is assumed.The method to optimise the search for suitable locations for thermal plants as well as for biomass extraction/collection areas, based on the combined use of GIS and spatial analysis techniques, is also described.