Dedicated agricultural and herbaceous crops

Agricultural and herbaceous crops can be used to produce renewable energy in a short time following establishment. Some perennial crops also offer protection against soil erosion, allowing them to be grown on land which would be unsuited to row-crop agriculture. When compared with woody biomass crops, harvesting the crop and putting it into a transportable form may be more expensive and the energy density is low, allowing shorter distances to the site of conversion to a more useful form of energy. Those crops which can be more easily converted to a liquid fuel appeared to be receiving the most attention. The current cost of producing renewable energy from these crops is greater than the cost of conventional fossil energy.     

An economic assessment of the use of short-rotation coppice woody biomass to heat greenhouses in southern Canada

This study explores the economic feasibility of fossil fuel substitution with biomass from short-rotation willow plantations as an option for greenhouse heating in southern Ontario, Canada. We assess the net displacement value of fossil fuel biomass combustion systems with an integrated purpose-grown biomass production enterprise. Key project parameters include greenhouse size, heating requirements, boiler capital costs and biomass establishment and management costs. Several metrics have been used to examine feasibility including net present value, internal rate of return, payback period, and the minimum or break-even prices for natural gas and heating oil for which the biomass substitution operations become financially attractive. Depending on certain key assumptions, internal rates of return ranged from 11-14% for displacing heating oil to 0-4% for displacing natural gas with woody biomass. The biomass heating projects have payback periods of 10 to >22 years for substituting heating oil and 18 to >22 years for replacing a natural gas. Sensitivity analyses indicate that fossil fuel price and efficiency of the boiler heating system are critical elements in the analyses and research on methods to improve growth and yield and reduce silviculture costs could have a large beneficial impact on the feasibility of this type of bioenergy enterprise.     

Life cycle impacts of waste wood biomass heating systems: A case study of three UK based systems

With increasing renewable energy targets and the use of biomass for energy production, questions arise about the sustainability of differing types of bioenergy. Much has been made about the renewable transport fuel obligations and the impact the production of biofuel can have on the environment, but there has been less consideration of more small scale biomass heating systems. This work examines the life cycle impacts of the production and use of three such systems using waste wood in the South West of England. Burning of wood in the UK was reduced after the introduction of legislation to reduce smog in the 1950s, and so the impact of the emissions from the boilers has been examined. Whilst the boilers studied complied with UK emissions legislation, the emissions were the most significant impact found. However, there were differences in the emission levels depending on the loading of the boiler. In all cases the energy payback of the systems was under one year, ranging from approximately four to ten months.     

Economic assessment and comparison of acacia energy crop with annual traditional crops in Southern Europe

In several policy documents bioenergy is recognized as an important renewable energy source in Italy. The increase in energy prices represents an opportunity for lignocellulosic energy crops such as acacia and poplar.     

Oil palm biomass as a sustainable energy source: A Malaysian case study

It has been widely accepted worldwide that global warming is by far the greatest threat and challenge in the new millennium. In order to stop global warming and to promote sustainable development, renewable energy is a perfect solution to achieve both targets. Presently million hectares of land in Malaysia is occupied with oil palm plantation generating huge quantities of biomass. In this context, biomass from oil palm industries appears to be a very promising alternative as a source of raw materials including renewable energy in Malaysia. Thus, this paper aims to present current scenario of biomass in Malaysia covering issues on availability and sustainability of feedstock as well as current and possible utilization of oil palm biomass. This paper will also discuss feasibility of some biomass conversion technologies and some ongoing projects in Malaysia related to utilization of oil palm biomass as a source of renewable energy. Based on the findings presented, it is definitely clear that Malaysia has position herself in the right path to utilize biomass as a source of renewable energy and this can act as an example to other countries in the world that has huge biomass feedstock.     

Second generation biofuels: Economics and policies

This study reviews economics of production of second generation biofuels from various feedstocks, including crop and wood/forestry residues, lignocellulosic energy crops, jatropha, and algae. The study indicates that while second generation biofuels could significantly contribute to the future energy supply mix, cost is a major barrier to its commercial production in the near to medium term. Depending upon type of biofuels, feedstock prices and conversion costs, the cost of cellulosic ethanol is found to be two to three times higher than the current price of gasoline on an energy equivalent basis. The median cost (across the studies reviewed) of biodiesel produced from microalgae, a prospective feedstock, is seven times higher than the current price of diesel, although much higher cost estimates have been reported. As compared with the case of first generation biofuels, in which feedstock can account for over two-thirds of the total costs, the share of feedstock in the total costs is relatively lower (30–50%) in the case of second generation biofuels. While significant cost reductions are needed for both types of second generation biofuels, the critical barriers are at different steps of the production process. For cellulosic ethanol, the biomass conversion costs needs to be reduced. On the other hand, feedstock cost is the main issue for biodiesel. At present, policy instruments, such as fiscal incentives and consumption mandates have in general not differentiated between the first and second generation biofuels except in the cases of the US and EU. The policy regime should be revised to account for the relative merits of different types of biofuels.     

Energy crops in rotation. A review

The area under energy crops has increased tenfold over the last 10 years, and there is large consensus that the demand for energy crops will further increase rapidly to cover several millions of hectares in the near future. Information about rotational systems and effects of energy crops should be therefore given top priority. Literature is poor and fragmentary on this topic, especially about rotations in which all crops are exclusively dedicated to energy end uses. Well-planned crop rotations, as compared to continuous monoculture systems, can be expected to reduce the dependence on external inputs through promoting nutrient cycling efficiency, effective use of natural resources, especially water, maintenance of the long-term productivity of the land, control of diseases and pests, and consequently increasing crop yields and sustainability of production systems. The result of all these advantages is widely known as crop sequencing effect, which is due to the additional and positive consequences on soil physical-chemical and biological properties arising from specific crops grown in the same field year after year. In this context, the present review discusses the potential of several rotations with energy crops and their possibilities of being included alongside traditional agriculture systems across different agro-climatic zones within the European Union. Possible rotations dedicated exclusively to the production of biomass for bioenergy are also discussed, as rotations including only energy crops could become common around bio-refineries or power plants. Such rotations, however, show some limitations related to the control of diseases and to the narrow range of available species with high production potential that could be included in a rotation of such characteristics. The information on best-known energy crops such as rapeseed (Brassica napus) and sunflower (Helianthus annuus) suggests that conventional crops can benefit from the introduction of energy crops in the rotation; furthermore, a considerable number of lesser-known energy crops such as biomass sorghum (Sorghum spp.), hemp (Cannabis sativa), kenaf (Hibiscus cannabinus), Ethiopian mustard (Brassica carinata) could be expected to lead to even greater benefits according to literature. Therefore, this review aimed at systematizing and reorganizing the existing and fragmentary information on these crops while stressing major knowledge gaps to be urgently investigated.     

Biomass bale stack and field outlet locations assessment for efficient infield logistics

Harvested hay or biomass are traditionally baled for better handling and they are transported to the outlet for final utilization. For better management of bale logistics, producers often aggregate bales into stacks so that bale-hauling equipment can haul multiple bales for improved efficiency. Objectives of this research include simulation of bale collection logistics after forming subfield stacks, evaluation of location effects of bale stack and field outlet, the number of stacks, transported bales/trip, and other field parameters on logistics distances (aggregation, transportation, and total). The software ‘R’ performed the simulation, statistical analysis, and data visualization. Formation of bale stacks decoupled aggregation and transportation components. Stacks formation thus allows for aggregation and transportation to be performed at different times. Increasing the number of subfield stacks and the number of transported bales/trip significantly reduced the total logistics distances. The order for the best bale stack and outlet locations was: middle, near middle, mid-edge along the length, mid-edge along the width, and finally, corners. Except for swath and windrow variation, the studied field variables had a highly significant influence on the logistics distances. Increased bales/trip (≥6) reduced the variations of outlet locations. Locating the field outlet at or near the center of the field along with an appropriate number of square subfields with stacks at the middle, and increased bales/trip will be the most efficient infield logistics strategy.     

Life cycle assessment of different bioenergy production systems including perennial and annual crops

Energy crops are expected to greatly develop in a very short-term bringing to significant social and environmental benefits. Nevertheless, a significant number of studies report from very positive to negative environmental implications from growing and processing energy crops, thus great uncertainty still remains on this argument. The present study focused on the cradle-to-grave impact assessments of alternative scenarios including annual and perennial energy crops for electricity/heat or first and second generation transport fuels, giving special emphasis to agricultural practices which are frequently surprisingly neglected in Life Cycle Assessment studies despite a not secondary relevance on final outcomes. The results show that cradle-to-farm gate impacts, i.e. including the upstream processes, may account for up to 95% of total impacts, with dominant effects on marine water ecotoxicity. Therefore, by increasing the sustainability of crop management through minimizing agronomic inputs, or with a complementary use of crop resides, can be expected to significantly improve the overall sustainability of bioenergy chains, as well as the competitiveness against fossil counterparts. Once again, perennial crops resulted in substantially higher environmental benefits than annual crops. It is shown that significant amount of emitted CO₂ can be avoided through converting arable lands into perennial grasslands. Besides, due to lack of certain data, soil carbon storage was not included in the calculations, while N₂O emission was considered as omitted variable bias (1% of N-fertilization). Therefore, especially for perennial grasses, CO₂ savings were reasonably higher that those estimated in the present study. For first generation biodiesel, sunflower showed a lower energy-based impacts than rapeseed, while wheat should be preferred over maize for first generation bioethanol given its lower land-based impacts. For second generation biofuels and thermo-chemical energy, switchgrass provided the highest environmental benefits. With regard to bioenergy systems, first generation biodiesel was less impacting than first generation bioethanol; bioelectricity was less impacting than first generation biofuels and second generation bioethanol by thermo-chemical hydrolysis, but highly impacting than Biomass-to-Liquid biodiesel and second generation bioethanol through enzymatic hydrolysis.     

Projecting demand and supply of forest biomass for heating in Norway

This paper assesses the increase in demand and supply for forest biomass for heating in Norway in 2020. By then there is a political aim to double the national production of bioenergy from the level in 2008. The competitiveness of woody biomass in central and district heating is analyzed in a model selecting the least-cost heating technology and scale in municipalities given a set of constraints and under different fuels price scenarios. The supply of forest biomass from roundwood is estimated based on data of forest inventories combined with elasticities regarding price and standing volumes. The supply of biomass from harvesting residues is estimated in an engineering approach based on data from the national forest inventories and roundwood harvest. The results show how the production of bioenergy is affected by changes in energy prices and support schemes for bioenergy. One conclusion from the analyses is that the government target of 14 TWh more bioenergy by 2020 is not likely to be met by current technologies and policy incentives. The contribution of the analysis is the detailed presentation of the heat market potentials and technology choices combined with supply functions for both roundwood and harvesting residues.     

Quantification of employment from biomass power plants

One of the attractions of developing bioenergy systems is the potential for job creation and economic development of rural economies. This paper seeks to quantify the expected employment impacts of individual bioenergy developments. The assessment includes agricultural labour growing energy crops for SRC and miscanthus options, transport and processing of the feedstock, staffing at the thermal conversion plant, employment within the equipment supply chain and the induced employment impact. Power only bioenergy systems are shown to typically create 1.27 man years of employment per GWh electricity produced, regardless of technology or scale of implementation. CHP systems can create more than 2 man years of employment per GWh electricity produced, although most of this enhanced economic impact can be attributed to the fact that a comparative analysis per unit of electricity produced ignores the heat output of the system.     

Analysis of biomass residues potential for electrical energy generation in Albania

This paper presents the status of research of biomass potential for producing electrical energy in Albania. Biomass potential can be generated by different sources. Three types of biomass energy sources are included: dedicated bioenergy crops, agricultural and forestry residues and waste. The technical electrical energy considered in this study was calculated with two converting techniques: (1) combustion of the feedstock directly in an incinerator and then driving a steam generator for producing electrical energy and (2) production of biogas from an anaerobic digester and running a turbine for electrical energy generation. Analysis of the potential biomass resource quantity was computed according to statistical reports, literature review and personal investigations. From the biomass residue potential was calculated in terms of the theoretical energy content (total heating value) of every type of feedstock and the technical energy content for every Albanian prefecture according to different burning processes and different operation efficiencies. Results show that Albania was producing around of 4.8 million tons of dry biomass in year 2005. The theoretical energy content of biomass in Albania was 11.6 million MWh/a, and the technical electrical energy production was 3 million MWh/a. The electrical energy produced is equivalent to 45.8% of total Albania Country annual electrical consumption. In Albania Country, residues from agriculture, forest and urban waste represent a large biomass potential. By actual conversion techniques it is possible to generate one third of the theoretical heat energy into technical electrical energy. The use of heat from cogeneration plants depends on local heat provision conditions. It is another big energy potential but excluded in this study, so the rest of energy is considered as heat losses.     

Importance of biomass energy as alternative to other sources in Turkey

Energy plays a vital role in socio–economic development and raising standards of human beings. Turkey is a rapidly growing country; both its population and economy are expanding each year so its energy demand increases correspondingly and this increasing demand has to be met for keeping sustainable development in the economy and raising living conditions of mankind. Although Turkey has many energy sources, it is a big energy importer. Turkey has a lot of potential to supply its own energy, which could be put to use in order to avoid this energy dependence. Additionally, Turkey is a country that has an abundance of renewable energy sources and can essentially provide all energy requirements from indigenous energy sources. Biomass is one of the most promising energy sources considered to be alternative to conventional ones.     

Cost efficient utilisation of biomass in the German energy system in the context of energy and environmental policies

The possible uses of biomass for energy provision are manifold. Gaseous, liquid and solid bioenergy carriers can be alternatively converted into heat, power or transport fuel. The contribution of the different utilisation pathways to environmental political targets for greenhouse gas (GHG) emission reduction and energy political targets for the future share of renewable energy vary accordingly to their techno-economic characteristics. The aim of the presented study is to assess the different biomass options against the background of energy and environmental political targets based on a system analytical approach for the future German energy sector. The results show that heat generation and to a lower extent combined heat and power (CHP) production from solid biomass like wood and straw are the most cost effective ways to contribute to the emission reduction targets. The use of energy crops in fermentation biogas plants (maize) and for production of 1st generation transportation fuels, like biodiesel from rapeseed and ethanol from grain or sugar beet, are less favourable. Optimisation potentials lie in a switch to the production of 2nd generation biofuels and the enhanced use of either biomass residues or low production intensive energy crops.     

Energy crops and pesticide contamination: Lessons learnt from the development of energy crop cultivation in Germany

Biomass provides two thirds of the total energy produced from renewables in Europe. The share of bioenergy from energy crops is growing rapidly. Given the environmental pressures arising from pesticide pollution from current agricultural food production, a substantial increase in energy crop cultivation might put additional pressure on biodiversity and soil and water resources. In the present study, we examine the potential of energy crops for pesticide contamination and develop general conclusions and recommendations for the future large-scale expansion of agricultural bioenergy. We base our analysis on the development of energy crop cultivation in Germany, the European country with the largest share of energy crops. Our findings reveal that there will not necessarily be an increase or decrease in the amounts of pesticides released into the environment. Due to the great variety of energy crops, the potential effects will depend rather on the future design of the agricultural systems. Possible risks are associated with the increased cultivation of pesticide-intensive energy crops, such as rapeseed, especially when grown in monocultures or on formerly set-aside land or converted grassland. Instead, energy crops should be integrated into the existing food production systems. Financial incentives and further education are needed to encourage the use of sustainable crop rotations, innovative cropping systems and perennial energy crops, which may add to crop diversity and generate lower pesticide demands than intensive food farming systems. Optimised cultivation systems with diverse crop rotations could help to improve monotonous agricultural landscapes, increase biodiversity and minimise pesticide exposure.     

Inventory and classification of United States federal and state forest biomass electricity and heat policies

As of September 2013, federal and state governments had nearly 500 policies to support production of electricity and heat from forest biomass. This research used a four-tier classification structure to categorize policy instruments used in these policies based on: approach (incentive, regulation, information), type (e.g. tax incentive), subcategory (e.g. tax exemption), and specification (e.g. sales tax exemption). More (113) of these policies were enacted in 2007 and 2008, more than in any other two-year period, and there was a significant increase in the number of forest bioenergy (46) and biomass specific (36) policies by 2013. Cluster analysis provided evidence that neighboring states adopted similar numbers and types of policies. Oregon (in cluster by itself) had the highest number of tax incentives and biomass-specific policies, while most Southern, Southeast, Southern Appalachia and Midwestern states (the most dissimilar cluster to Oregon) had a limited number of policies. Most states in remaining clusters offered a mix of integrated policies, rather than policies focused on regulations and technology improvement. Our findings provide guidance for policy development by enabling the transfer of policy approaches among different states and regions.     

Review of consumption trends and public policies promoting woody biomass as an energy feedstock in the U.S.

A review of the four main wood energy sectors in the U.S. was conducted to explore historic trends and the impact of alternative energy prices and public policies on wood energy consumption. High oil prices have triggered the adoption of government regulation and financial incentives to promote greater use of wood energy over the last four decades. However, the amount of wood energy consumed in the U.S. industrial sector was driven mainly by the output of the pulp and paper products industry and not by energy prices or any particular public policy incentive. Residential consumption of wood energy was positively correlated with competing energy prices. Public policies seem to have had a greater impact on wood energy consumption in the electric power sector and over the last four decades have concentrated on promoting biopower with a recent shift to liquid cellulosic biofuels. High oil prices and a series of public policies such as tax credits, loans, grants, and renewable energy standards have resulted in higher consumption of wood energy from 2004 to 2009 in the residential, electric power and commercial sectors by an estimated 5, 2, and less than 1 percent annually, respectively. The impact of new federal programs such as the Biomass Crop Assistance Program remains to be observed. Continuation of public incentives and preferential regulations for renewable energy appears to be necessary for a steady increase in U.S. wood energy consumption.     

Biomass and energy production of catch crops in areas with deficiency of precipitation during summer period in central Bohemia

The biomass production dynamics of catch crops, volunteers and weeds in dependence on precipitation and air temperature, was studied in central Bohemia from 2004 to 2006. The cover of individual components of the growth was monitored during the same period. Also measured were energy and efficiency of utilization of global radiation by catch crops and volunteers. The catch crops included the following species: Brassica napus, Lolium multiflorum, Lolium perenne, Phacelia tanacetifolia, Sinapis alba, Trifolium incarnatum, Raphanus sativus var. oleiformis and Trifolium subterraneum. The highest biomass production and the highest cover of catch crops were observed in treatments with S. alba (1382.0 kg ha⁻¹, 47.8%). The average biomass production (sum of catch crops, volunteers and weeds) was highest in treatments with S. alba, R. sativus, and P. tanacetifolia and lowest in treatments with B. napus, L. multiflorum and L. perenne. It was demonstrated that an increase in the percentage share of volunteers caused a decrease in the biomass production of catch crops. The average energy production ranged from 0.31 to 2.37 MJ m⁻² in treatments with catch crops, and from 0.25 to 0.89 MJ m⁻² in treatments with cereal volunteers. The highest effectivity of global radiation utilization, was determined in treatments with S. alba (0.11-0.47%). Based on regression analysis the closest dependence between biomass production from all treatments on the experimental site and precipitation was observed from 1st May till the time of sowing and the average air temperatures from the sowing period till the time of the last biomass production assessment.     

Development and application of BioFeed model for optimization of herbaceous biomass feedstock production

An efficient and sustainable biomass feedstock production system is critical for the success of the biomass based energy sector. An integrated systems analysis framework to coordinate various feedstock production related activities is, therefore, highly desirable. This article presents research conducted towards the creation of such a framework. A breadth level mixed integer linear programming model, named BioFeed, is proposed that simulates different feedstock production operations such as harvesting, packing, storage, handling and transportation, with the objective of determining the optimal system level configuration on a regional basis. The decision variables include the design/planning as well as management level decisions. The model was applied to a case study of switchgrass production as an energy crop in southern Illinois. The results illustrated that the total cost varied between 45 and 49 $ Mg⁻¹ depending on the collection area and the sustainable biorefinery capacity was about 1.4 Gg d⁻¹. The transportation fleet consisted of 66 trucks and the average utilization of the fleet was 86%. On-farm covered storage of biomass was highly beneficial for the system. Lack of on-farm open storage and centralized storage reduced the system profit by 17% and 5%, respectively. Increase in the fraction of larger farms within the system reduced the cost and increased the biorefinery capacity, suggesting that co-operative farming is beneficial. The optimization of the harvesting schedule led to 30% increase in the total profit. Sensitivity analysis showed that the reduction in truck idling time as well as increase in baling throughput and output density significantly increased the profit.     

Regional economic impacts of biomass based energy service use: A comparison across crops and technologies for East Styria,Austria

Biomass action plans in many European countries seek to expand biomass heat and fuel supply, mainly to be supplied by peripheral, agricultural regions. We develop a two-plus-ten-region energy-focused computable general equilibrium (CGE) model that acknowledges land competition in analysing the sub-state local-regional economic implications of such a strategy, embedded within a global context. Our model is based on a full cost analysis of selected biomass technologies covering a range of agricultural and forestry crops, as well as thermal insulation. The local-regional macroeconomic effects differ significantly across technologies and are governed by factors such as net labour intensity in crop production. The high land intensity of agricultural biomass products crowds out conventional agriculture, and thus lowers employment and drives up land prices and the consumer price index. The regional economic results show that net employment effects are positive for all forestry based biomass energy, and also show for which agriculture based biomass systems this is true, even when accounting for land competition. When regional consumer price development governs regional wages or when the agricultural sector is in strong enough competition to the international market, positive employment and welfare impacts vanish fully for agriculture based bio-energy.