Sustainable Biomass Source Research Articles

BECCS Opportunities in Brazil: Pre and Post-Combustion Comparison in a Typical Sugarcane Mill

In order to make feasible the efforts that would limit the rise of Earth's temperature to no more than 2°C, profound changes are required in the energy systems. In this sense, BECCS (sustainable bioenergy systems, combined with carbon capture and storage) are considered instrumental to attain possible negative emissions. This brings the attention to the sugarcane industry in Brazil, in which it is possible to produce fuel ethanol at a relative low cost and a large amount of relatively cheap biomass is available. The already good results related to the avoided emissions could be further improved with the storage of the CO2 produced during fermentation. In addition, with not yet commercial BIG-CC systems (biomass-integrated gasification to combined cycle), it would be possible to at least double the generation of electricity at a sugarcane plant, compared to the results of conventional cogeneration systems. In this case, as biomass gasification is required, it would be possible to use pre-combustion capture technologies, reducing energy penalties. This article is part of a research that aims to study the combined production of liquid fuels and electricity, using sustainable sources of biomass and maximizing carbon capture. In both cases evaluated, the capture is based on amine technology: pre-combustion capture of CO2 from the fuel gas derived from biomass gasification, and post-combustion capture from gas turbine exhaust gases. Modelling is based on literature information for all systems, as well as for estimating energy penalties associated with CO2 capture, transport and storage. The results indicate technical feasibility for both technologies, but difficulties in setting the full integration of the BIG-CC unit with the sugarcane mill and the CCUS system, due to the high demand for thermal energy as low pressure steam. The estimated CO2 abatement cost is in the range 66–77 €/tCO2 for pre-combustion capture, and 58–68 €/tCO2 in the case of post-combustion. Feasibility results are impacted by the scale of CO2 capture from the combustion gases (0.54–1.11 MtCO2/year), mainly in the pre-combustion case, and by the relatively high cost of electricity generation (46 €/MWh).

ЕКО-БІО-ЕКОНОМІЧНА СТРАТЕГІЯ ЯК КОНЦЕПЦІЯ СТАЛОГО РОЗВИТКУ СІЛЬСЬКИХ ТЕРИТОРІЙ

In the article the scientific-theoretical substantiation of priority directions of development of rural territories is carried out. It is determined that the bioeconomy is seen as part of the transition to sustainable rural development, which promotes green and inclusive growth, while going beyond the “natural economy” with low productivity and economies with high consumption of fossil resources, which have reached their limit. It is noted that the process of formation of the bioeconomy involves the transition of the most important industries, including agriculture, to the use of renewable bioresources. The main visions and opportunities of the bioeconomy, in particular for the development of rural areas, developed by specialists of the CAP (General Agricultural Policy) in the EU have been studied. The main ones are the vision of bioresources (substitution), the vision of agricultural innovations and rural development, the vision of international cooperation and development, the vision of bioecology. The main risks associated with the transition to a bioeconomy are analyzed, namely the increase in the load on bioresources, the formation of additional demand and competition, increasing demand for land, water and other natural resources. The main risk associated with the transition to a bioeconomy is that industrialized countries, such as European countries, will maintain their resource-intensive consumption patterns, based on increased net imports of raw bioresources (using the bioeconomy as an excuse to continue doing business in normal mode), while at the same time some countries of the global south remain or become suppliers of these bioresources without advancing to the modern bioeconomy, which includes adding the value of biomass to the supply chain. It has been found that, depending on the context and pathways of the bioeconomy, some of the negative impacts may be even stronger per unit of bio-based products compared to fossil-based products. The implementation of the EU-Ukraine bioeconomic strategy should be supported by a database of information related to the production, processing and (reuse) of bioresources, as well as the benefits gained. It has been shown that a combination of sustainable biomass sources and sustainable agricultural intensification with the support of a coherent policy can increase the availability of bioresources and food security.

Biochar and its Use in Soil: Lessons from Temperate Agriculture

Biochar is a carbon-rich product that is obtained when a sustainable source of biomass is heated without oxygen. Biochar is produced in the same way as charcoal, but its intended use differs. Biochar is manufactured with a specific set of properties (e.g. adsorption properties, ion exchange capacity, low bulk density) for its use as soil amendment and/or adsorbent

Sustainable biomass portfolio sourcing plan using multi-stage stochastic programming

Selecting the most sustainable biomass sources for biofuel production can overcome sever obstacles in the reliable supply of biomass feedstock, such as its seasonal availability. Developing a biomass portfolio can generally improve the sustainability of future biofuel systems. Bioethanol is an attractive biofuel having the potential for enhancing energy security and environmental safety over fossil fuels. The decisions to be made comprise the optimum amount of bioethanol feedstocks, and the investments to make in alternative activities. Uncertainty is assumed for biomass conversion rate to bioethanol, which is described by a set of scenarios. Therefore, for the entire planning horizon, a tree of scenarios is organized. The problem is formulated as a multi-stage stochastic linear programming problem. The goal is to maximize the total financial benefit. The risk associated with biomass availability affects the viability of biomass utilization and, therefore, should be taken into account when evaluating and analyzing biomass portfolio. In addition, the conditional value at risk (CVaR) is adopted to consider the risk hedge. Using a real case study, computational experiments are presented, showing that the stochastic approach is worth considering in these types of problems. Case study results demonstrate the validity of the proposed model.

Implications of agar and agarase in industrial applications of sustainable marine biomass.

Agar, a major component of the cell wall of red algae, is an interesting heteropolysaccharide containing an unusual sugar, 3,6-anhydro-L-galactose. It is widely used as a valuable material in various industrial and experimental applications due to its characteristic gelling and stabilizing properties. Agar-derived oligosaccharides or mono-sugars produced by various agarases have become a promising subject for research owing to their unique biological activities, including anti-obesity, anti-diabetic, immunomodulatory, anti-tumor, antioxidant, skin-whitening, skin-moisturizing, anti-fatigue, and anti-cariogenic activities. Agar is also considered as an alternative sustainable source of biomass for chemical feedstock and biofuel production to substitute for the fossil resource. In this review, we summarize various biochemically characterized agarases, which are useful for industrial applications, such as neoagarooligosaccharide or agarooligosaccharide production and saccharification of agar. Additionally, we succinctly discuss various recent studies that have been conducted to investigate the versatile biological activities of agar-derived saccharides and biofuel production from agar biomass. This review provides a basic framework for understanding the importance of agarases and agar-derived saccharides with broad applications in pharmaceutical, cosmetic, food, and bioenergy industries.

Impact of hydrolysis on surface area and energy storage applications of activated carbons produced from corn fiber and soy hulls

Complete utilization of lignocellulosic biomass through the creation of value-added coproducts is one of the key strategies of the Bioenergy Technologies Office (BETO) for the cost-effective production of biofuels and biochemicals. A green approach to producing lightweight and high specific surface area (SSA) activated carbons (ACs) from sustainable biomass sources is of great interest to producers and users of energy devices such as batteries and supercapacitors. While direct conversion from biomass has been studied extensively, AC with relatively high surface areas can be produced more cost-effectively when leveraged as a co-product from a biorefinery. In this paper, we discuss the production of high specific surface area activated carbons from residual fiber (fiber remaining after extraction of C5-sugars) generated as part of a C5 biorefinery. The surface, morphological characteristics using SEM and TEM, and energy storage behavior of ACs produced using the C5 extracted residual fiber were evaluated in the present study. The ACs produced from the residual fiber delivered an order of magnitude higher surface area than the one directly from corn pericarp fiber and soy hulls. The surface area of the ACs produced from pre-hydrolysis DDG was only 10 m2/g compared to 689 m2/g for soy hulls whereas after hydrolysis these values increased significantly (DDG: 1700 m2/g and soy hulls: 1300 m2/g). TEM images indicated high exfoliation, explaining the change in surface area values. Under the same current density (500 mA/g) the cycling performance of the ACs increased as the surface area increased significantly.

Evaluation of synthetic bio-phenol resins derived from biomass gasification in bio-adhesive formulation

Bio-phenol formaldehyde adhesives formulated from sustainable biomass sources is an excellent alternative to phenolic petroleum-based adhesives with lower pollution level. This study aimed to formulate bio-adhesive from two types of biomass namely palm kernel shell (PKS) and Leucaena sp. Wood. The intention was to find the best process condition which results in maximum content of bio-phenol in the product. The bio-based phenolic resins (bio-oils) were produced from gasification process and their physical and chemical properties were determined. Both produced bio-oils were involved in formulation of bio-based phenol formaldehyde adhesives (resinification) at different operating conditions (temperature, time and catalyst loading). The chemical functional groups and individual compounds of the phenol resins and bio-adhesive samples were identified by GC-MS. The results indicated that temperature has persistent increasing effect on phenol percent of the bio-oil from Leucaena sp. wood however for the bio-oil from PKS the increase of phenol was until the temperature of 85 °C. Reaction time and catalyst loading were observed to have similar effects on resinification of both bio-oil samples. The bio-adhesive produced under best operating condition has the highest amount of bio-phenol and therefore is considered an environmental friendly adhesive with lower cost and pollution than the petroleum-based types.

Breeding Strategies to Improve Miscanthus as a Sustainable Source of Biomass for Bioenergy and Biorenewable Products

Miscanthus, a C4 perennial grass native to Eastern Asia, is being bred to provide biomass for bioenergy and biorenewable products. Commercial expansion with the clonal hybrid M. × giganteus is limited by low multiplication rates, high establishment costs and drought sensitivity. These limitations can be overcome by breeding more resilient Miscanthus hybrids propagated by seed. Naturally occurring fast growing indigenous Miscanthus species are found in diverse environments across Eastern Asia. The natural diversity provides for plant breeders, the genetic resources to improve yield, quality, and resilience for a wide range of climates and adverse abiotic stresses. The challenge for Miscanthus breeding is to harness the diversity through selections of outstanding wild types, parents, and progenies over a short time frame to deploy hybrids that make a significant contribution to a world less dependent on fossil resources. Here are described the strategies taken by the Miscanthus breeding programme at Aberystwyth, UK and its partners. The programme built up one of the largest Miscanthus germplasm collections outside Asia. We describe the initial strategies to exploit the available genetic diversity to develop varieties. We illustrate the success of combining diverse Miscanthus germplasm and the selection criteria applied across different environments to identify promising hybrids and to develop these into commercial varieties. We discuss the potential for molecular selections to streamline the breeding process.

Prediction and estimation of biomass energy from agricultural residues using air gasification technology in Iran

Biomass energy has great potential to create significant impacts on the most pressing development challenges of rural poverty and environmental damage. Iran’s agricultural residues have the potential to generate a sustainable source of biomass. One method of sustainable biomass energy production is gasification. The objective of the present study is to develop a stoichiometric equilibrium model for the prediction of energy production of gasification. The model was validated with experimental data in order to determine the syngas composition. The RMSE of the modified model was ranged from 0.571 to 1.10. Subsequently, the effects of parameters of operating conditions on the performance of gasification were evaluated to determine its optimal performance characteristics. Also, the developed model was used to estimate the amount of power and heat obtained from different agricultural residues by the gasification process. The results indicated that the total achieved energy from the agricultural residues by gasification technology was 341,290 TJ. Also, the amount of electricity and heat obtained from this energy was 66,075 and 3 99,112 TJ, respectively.

Highly Porous Willow Wood-Derived Activated Carbon for High-Performance Supercapacitor Electrodes.

In this study, we present willow wood as a new low-cost, renewable, and sustainable biomass source for the production of a highly porous activated carbon for application in energy storage devices. The obtained activated carbon showed favorable features required for excellent electrochemical performance such as high surface area (∼2 800 m2 g–1) and pore volume (1.45 cm3 g–1), with coexistence of micropores and mesopores. This carbon material was tested as an electrode for supercapacitor application and showed a high specific capacitance of 394 F g–1 at a current density of 1 A g–1 and good cycling stability, retaining ∼94% capacitance after 5 000 cycles (at a current density of 5 A g–1) in 6 M KOH electrolyte. The prepared carbon material also showed an excellent rate performance in a symmetrical two-electrode full cell configuration using 1 M Na2SO4 electrolyte, in a high working voltage of 1.8 V. The maximum energy density and power density of the fabricated symmetric cell reach 23 W h kg–1 and 10 000 W kg–1, respectively. These results demonstrate that willow wood can serve as a low-cost carbon feedstock for production of high-performance electrode material for supercapacitors.

Evaluation on the Methane Production Potential of Wood Waste Pretreated with NaOH and Co-Digested with Pig Manure

Wood waste generated during the tree felling and processing is a rich, green, and renewable lignocellulosic biomass. However, an effective method to apply wood waste in anaerobic digestion is lacking. The high carbon to nitrogen (C/N) ratio and rich lignin content of wood waste are the major limiting factors for high biogas production. NaOH pre-treatment for lignocellulosic biomass is a promising approach to weaken the adverse effect of complex crystalline cellulosic structure on biogas production in anaerobic digestion, and the synergistic integration of lignocellulosic biomass with low C/N ratio biomass in anaerobic digestion is a logical option to balance the excessive C/N ratio. Here, we assessed the improvement of methane production of wood waste in anaerobic digestion by NaOH pretreatment, co-digestion technique, and their combination. The results showed that the methane yield of the single digestion of wood waste was increased by 38.5% after NaOH pretreatment compared with the untreated wood waste. The methane production of the co-digestion of wood waste and pig manure was higher than that of the single digestion of wood waste and had nonsignificant difference with the single-digestion of pig manure. The methane yield of the co-digestion of wood waste pretreated with NaOH and pig manure was increased by 75.8% than that of the untreated wood waste. The findings indicated that wood waste as a sustainable biomass source has considerable potential to achieve high biogas production in anaerobic digestion.

Hydrodynamic cavitation for energy efficient and scalable process of microalgae cell disruption

Microalgae are likely to emerge as a sustainable source of biomass which can be utilized as food, feed, and fuel. Most of the valuable products in the microalgae are present intracellular. Microalgae cell wall is rigid and mainly composed of cellulose. Hence, it is essential to disrupt cells to extract intracellular products. Probe ultrasonication (US) and hydrodynamic cavitation (HC) were optimized for their operating parameters and various pre-treatments to obtain maximum cell disruption efficacy. Optimum conditions for maximum cell disruption using US were: solid load (1% w/v), duty cycle (80%), power input (54 W) and the US time 90 min. After pre-treatment with 0.5% w/v sodium hydroxide; the time required for the maximum cell disruption using US was reduced to 50 min. Optimum conditions for the maximum cell disruption using HC were cavitation device orifice over venturi, time (180 min), pressure (5 bar) and solid load (0.45% w/v). After pre-treatment with 0.5% w/v sodium hydroxide time required for maximum cell disruption using HC was reduced to 105 min. Further, the energy required for cell disruption using US and HC was calculated and, it was found that HC was significantly more energy efficient and scalable treatment for microalgae cell disruption.

Mechanical and physical properties of regenerated biomass composite films from lignocellulosic materials in ionic liquid

As an important sustainable source of biomass, lignocellulosic materials are highly recalcitrant to biotransformation, which limits their use and prevents economically viable conversion into value-added products. Ionic liquids (ILs) have emerged as attractive solvents for lignocellulosic biomass pretreatment in the production of biochemical feedstocks. In this work, a mixture of wood powder and waste paper was dissolved in the ionic liquid 1-allyl-3-methylimidazolium chloride ([AMIM]Cl). Composite films were made from the regenerated lignocellulosic materials in [AMIM]Cl by adjusting the ratio of the raw materials. The physical and mechanical properties of biomass composite films were determined by optical microscopy (OM), Fourier transform infrared (FTIR) spectra, X-ray diffraction (XRD), and tensile strength tests. The results indicated that lignocellulosic materials were dissolved in [AMIM]Cl by destroying inter- and intramolecular hydrogen bonds between lignocelluloses. With increasing waste paper cellulose content, the dissolution of the fir powder in [AMIM]Cl was accelerated, and the tensile strength and elongation at break of the composite films increased. The rate of dissolution initially rose rapidly with increasing content of waste paper cellulose content, but the rate leveled off when the content was above 40%. This research highlights new opportunities for biodegradable composite films made from waste biomass.

Characterization of agar from Gracilaria tikvahiae cultivated for nutrient bioextraction in open water farms

Gracilaria tikvahiae, an endemic western North Atlantic red alga, was cultivated for nutrient bioextraction in urbanized estuarine waters in Long Island Sound and the Bronx River Estuary, USA. This study assesses the feasibility of an integrated approach of using G. tikvahiae produced in this bioextraction system as sustainable biomass source for agar production. Agars were extracted after alkaline pre-treatment and characterized in terms of gelling strength, chemical composition, chemical structure and gel structure. Results indicated that this seaweed performed similar to other cultivated Gracilaria in terms of extraction yield and gelling strength of the agar. Differences between sites were not significant in terms of agar gel strength, though yield was higher at Long Island Sound. The extracted agars were sulfated, methylated and with no detectable pyruvate substituents. It is possible to use an integrated strategy of nutrient bioextraction in urbanized estuarine waters and agar exploitation with G. tikvahiae.

Extraction, optimization, and characterization of lipids from spent hens: An unexploited sustainable bioresource

Spent hen, a poultry industry by-product with little market value and high lipid content, can be used as a new and sustainable biomass source for lipid production. This study focused on conventional extraction methods and compared them with the microwave-assisted extraction of lipids from the spent hen. Over 95% of the lipids were recovered within 10 min using microwaves. Factors affecting the extraction conditions, including extraction time, temperature, and the solvent-to-feed ratio on the lipid extraction yield were studied using response surface methodology. To account for the low sample size, parametric bootstrapping was used with a replacement approach. Data in all combinations were bootstrapped 10,000 times, which showed a decrease in standard deviation. Fatty acid profiles of extracts obtained in different conditions were investigated using gas chromatography equipped with mass spectrometry and a flame ionization detector for qualitative and quantitative analysis, respectively. The lipids predominantly contained oleic (46%), linoleic (∼22%), and palmitic (∼23%) acids. Proton nuclear magnetic spectroscopy and Fourier transform infrared spectroscopy were used to characterize different functional groups in the lipids. The phase transitions and thermal degradation behavior of lipids were determined using differential scanning calorimetry and thermogravimetric analysis, respectively.

DArT, SNP, and SSR analyses of genetic diversity in Lolium perenne L. using bulk sampling

BackgroundLolium perenne L. is the most important forage grass species in temperate regions. It is also considered as a sustainable source of biomass for energy production. However, improvement in biomass yield has been limited by comparison with other major crops. More efficient utilisation of genetic resources and improved breeding schemes are required to advance L. perenne breeding. In an attempt to elucidate the extent of genetic diversity in L. perenne, 1384 DArT, 182 SNP and 48 SSR markers were applied to 297 accessions (Set I) contributed by three German breeding companies and the IPK Genebank. Due to the heterogeneous nature of Lolium accessions, bulk samples were used. Apart from germplasm set I, additional set II and set III was used to determine the reproducibility of marker system and judge the feasibility of bulk strategy in this study.ResultsBy assessing different bulk sizes, 24 individuals per sample were shown to be a representative number of plants to discriminate different accessions. Among the 297 accessions, all marker types revealed a high polymorphism rate; 1.99, 2.00 and 8.19 alleles, were obtained per locus on average using DArTs, SNPs and SSRs, respectively. The Jaccard distance for DArT markers ranged from 0.00 to 0.73, the Modified Roger’s distance (MRD) for SNP markers ranged from 0.03 to 0.52, and for SSR markers from 0.26 to 0.76. Gene diversity for dominant DArT and co-dominant SNP and SSR markers was found to be 0.26, 0.32 and 0.45, respectively. DArT markers showed the highest consistency and reproducibility.ConclusionThe resulting data were evaluated using a number of different classification methods, but none of the methods showed a clear differentiation into distinct genetic pools. With regard to hybrid breeding, this will possibly impede substantial progress towards increased biomass yields of L. perenne by utilising heterosis.

Impact of Flue Gas Compounds on Microalgae and Mechanisms for Carbon Assimilation and Utilization.

To shift the world to a more sustainable future, it is necessary to phase out the use of fossil fuels and focus on the development of low-carbon alternatives. However, this transition has been slow, so there is still a large dependence on fossil-derived power, and therefore, carbon dioxide is released continuously. Owing to the potential for assimilating and utilizing carbon dioxide to generate carbon-neutral products, such as biodiesel, the application of microalgae technology to capture CO2 from flue gases has gained significant attention over the past decade. Microalgae offer a more sustainable source of biomass, which can be converted into energy, over conventional fuel crops because they grow more quickly and do not adversely affect the food supply. This review focuses on the technical feasibility of combined carbon fixation and microalgae cultivation for carbon reuse. A range of different carbon metabolisms and the impact of flue gas compounds on microalgae are appraised. Fixation of flue gas carbon dioxide is dependent on the selected microalgae strain and on flue gas compounds/concentrations. Additionally, current pilot-scale demonstrations of microalgae technology for carbon dioxide capture are assessed and its future prospects are discussed. Practical implementation of this technology at an industrial scale still requires significant research, which necessitates multidisciplinary research and development to demonstrate its viability for carbon dioxide capture from flue gases at the commercial level.

Co-production of 11\u03b1-hydroxyprogesterone and ethanol using recombinant yeast expressing fungal steroid hydroxylases

BackgroundBioethanol production from sustainable sources of biomass that limit effect on food production are needed and in a biorefinery approach co-products are desirable, obtained from both the plant material and from the microbial biomass. Fungal biotransformation of steroids was among the first industrial biotransformations allowing corticosteroid production. In this work, the potential of yeast to produce intermediates needed in corticosteroid production is demonstrated at laboratory scale following bioethanol production from perennial ryegrass juice.ResultsGenes encoding the 11α-steroid hydroxylase enzymes from Aspergillus ochraceus (11α-SHAoch) and Rhizopus oryzae (CYP509C12) transformed into Saccharomyces cerevisiae for heterologous constitutive expression in p425TEF. Both recombinant yeasts (AH22:p11α-SHAoch and AH22:p509C12) exhibited efficient progesterone bioconversion (on glucose minimal medial containing 300 µM progesterone) producing either 11α-hydroxyprogesterone as the sole metabolite (AH22:p11α-SHAoch) or a 7:1 mixture of 11α-hydroxyprogesterone and 6β-hydroxyprogesterone (AH22:p509C12). Ethanol yields for AH22:p11α-SHAoch and AH22:p509C12 were comparable resulting in ≥75% conversion of glucose to alcohol. Co-production of bioethanol together with efficient production of the 11-OH intermediate for corticosteroid manufacture was then demonstrated using perennial ryegrass juice. Integration of the 11α-SHAoch gene into the yeast genome (AH22:11α-SHAoch+K) resulted in a 36% reduction in yield of 11α-hydroxyprogesterone to 174 µmol/L using 300 µM progesterone. However, increasing progesterone concentration to 955 µM and optimizing growth conditions increased 11α-hydroxyprogesterone production to 592 µmol/L product formed.ConclusionsThe progesterone 11α-steroid hydroxylases from A. ochraceus and R. oryzae, both monooxygenase enzymes of the cytochrome P450 superfamily, have been functionally expressed in S. cerevisiae. It appears that these activities in fungi are not associated with a conserved family of cytochromes P450. The activity of the A. ochraceous enzyme was important as the specificity of the biotransformation yielded just the 11-OH product needed for corticosteroid production. The data presented demonstrate how recombinant yeast could find application in rural biorefinery processes where co-production of value-added products (11α-hydroxyprogesterone and ethanol) from novel feedstocks is an emergent and attractive possibility.

Seeing the forest for the trees: How much woody biomass can the Midwest United States sustainably produce?

Widespread interest in advancing goals of energy independence, climate change mitigation, and rural economic development has led to unprecedented growth of the global bioeconomy. Continued development of this burgeoning industry relies upon the long-term availability of plentiful, sustainable sources of biomass. In the Midwest United States, efforts to secure such supplies have focused on herbaceous plants, either from the seeds or residues of annual crops or from perennial lignocellulosic species. Here, we explore the potential for this region to provide woody biomass from forests and short rotation woody crops (SRWC). We compare estimates of current and future availability—as defined by biophysical, technical, or economic potential—from four United States governmental entities. We find that estimates vary widely due to key parameter choices and assumptions, from current annual potential of 19.9–47.6 Mg (Mg, or metric ton) and future (year 2030) potential of 8.1–210.5 Mg. For the largest future estimate, the economic woody biomass potential from SRWC is triple that of forests. To complement these detailed assessments of flows, we introduce a comparison with biomass stocks to assess the long term sustainability of biomass extraction. We find that the average biomass growth rate of Midwestern forests (3.4%) is lower than estimated extraction rates when prices are high (3.7%) and even less sustainable for specific states, such as Minnesota (2.4% growth compared to 8.6% extraction). We recommend that future studies of biomass potential should (1) estimate stocks and flows all three categories (biophysical, technical, and economic) side-by-side, (2) improve the transparency of parameter assumptions, and (3) make models and methods available to the public so that readjustments of parameters can be tested and harmonized. The potential quantities and spatial distribution of the biomass potentials shown here can provide the basis both for planning of regional bioenergy production and for future work that explores the ecosystem services provided by agroforestry ecosystems.

Can Cuba find the way forward to a renewables-based future?

Few countries are better placed than Cuba for a move towards self-sufficiency in renewable energy. Not only does it have abundant wind and sunshine but also sustainable sources of biomass. Sugar cane waste – bagasse – of course; and, more unusually, hardwood, namely the invasive Marabu tree which is widely regarded as a pest. Andrew Mourant investigates.