Biomass production from traditional coppice management in northern Italy

Traditional coppice stands cover millions of hectares throughout Europe and offer large amounts of biomass. The study analyzed 10 commercial coppice harvesting operations in northwestern Italy, where modern machines were deployed. Removals, prices, work, revenues and costs were carefully determined. Firewood was the main product, representing between 70% and 100% of the total product mass and value. Traditional coppice stands often yield over 200 m³ of energy biomass per hectare, at the time of cut. Cable yarding operations were better organized than ground-based operations, which explained why they incurred the same harvesting cost, despite the more challenging site conditions under which they were deployed. Mean harvesting cost was 45 € m⁻³, of which about 10% was needed for felling, 70% for extraction and processing, and the remaining 20% for loading and transportation. All operations accrued some profit, which varied between 13 and 43 € m⁻³ or between 1600 and 8600 € ha⁻¹, depending on operational efficiency, value recovery and stand yield.     

Energy dynamics and bioenergy production of Populus deltoides G-3 Marsh plantation in eastern India

The energy content of stems, branches, roots and litter was determined using an oxygen bomb calorimeter, and these data were used to estimate energy storage, net energy fixation and energy transfer within poplar (Populus deltoides G-3 Marsh) plantations of two ages at the Research Farm of Rajendra Agricultural University, Pusa, Bihar, India. Energy fixation, storage and energy released and exit from the 7-year-old plantation were 1.69, 2.11 and 1.53 times that of the 5-year-old plantation. The net energy fixation was 243.08 GJ ha^?1 year^?1 in 5-year-old and 410.57 GJ ha^?1 year^?1 in 7-year-old plantation. The energy conservation efficiency in the 7-year-old plantation was higher (1.51%) than that of the 5-year-old plantation (0.89%). The 5-year-old plantation showed lower energy accumulation ratio (2.02) resulting from less energy accumulation in components of poplar tree and greater annual turnover in terms of litter fall. The energy stored in the above-ground tree components from 2131.87 ha (5-year old) and 1002.88 ha (7-year old) or in the above-ground net annual production from 3924.15 ha (5-year old) and 2386.37 ha (7-year old) of poplar plantations is sufficient to operate a 5 MW generating station for 1 year. Above-ground biomass and net production from 1 ha of 5-year-old and 7-year-old poplar plantations is sufficient to meet the energy need of an average household in eastern India for 8.5 and 18.0 years and 4.6 and 7.6 years, respectively.     

Estimation of chemical traits in poplar short-rotation coppice at stand level

In order to improve qualitative traits of harvestable biomass and enhance its conversion into second generation biofuels (e.g. bioethanol), much attention should be paid to manage woody-energy plantations. This work represents an attempt to estimate chemical composition of biomass at stand level in poplar plantations. Based on the relationship between chemical traits of stem cross-sections and the corresponding distribution of diameter classes within the whole plantations, three different harvesting cycles were compared in terms of biomass yield and chemical composition. Under 2-year rotation, the stand showed the lower biomass annual yield (11.7 tDM ha^?1 y^?1) and the lower cellulose (42.5%) and the higher lignin (22%) proportion. On the contrary, under the 4-year cutting cycle, annual yield was not only higher (18.4 tDM ha^?1 y^?1), but the biomass also presented the highest cellulose (51.6%) and the lower lignin (19%) share. These results suggest that different management practices, including the cutting cycle, may affect not only yields but also qualitative traits of harvestable biomass of poplar short-rotation coppice.     

Feasibility assessment of poplar bioenergy systems in the Southern Europe

A detailed reliability assessment of bioenergy production systems based on poplar cultivation was made. The aim of this assessment was to demonstrate the Economic feasibility of implementing poplar biomass production for power generation in Spain. The assessment considers the following chain of energy generation: cultivation and harvesting, and transportation and electricity generation in biomass power plants (10, 25 and 50 MW). Twelve scenarios were analysed in accordance with the following: two harvesting methods (high density packed stems and chip production in the field), two crop distributions around the power plant and three power plant sizes. The results show that the cost of biomass delivered at power plant ranges from 18.65 to 23.96 € Mg^?1 dry basis. According to power plant size, net profits range from 3 to 22 million € per yr.Sensibility analyses applied to capital cost at the power plant and to biomass production in the field demonstrate that they do not affect the feasibility of these systems. Reliability is improved if benefits through selling CO₂ emission credits are taken into account.This study clears up the Economic uncertainty of poplar biomass energy systems that already has been accepted as environmentally friendlier and as offering better energetic performance.     

Estimates of technically available woody biomass feedstock from natural forests and willow biomass crops for two locations in New York State

A Geographic Information System (GIS) was used to estimate the technically available woody biomass from forests and willow biomass crops within a 40 km radius of Syracuse and Tupper Lake, NY. Land cover and land use data were used to identify the available land base and restrictions were applied for slope, parcel size and designated wetlands. Approximately 222,984 oven-dry tonnes (odt) of forest biomass are technically available annually around Syracuse, from 165,848 hectares (ha) of timberland. There are 67,880 ha of agricultural land technically available for growing willow biomass crops, which could produce 38,181 odt yr^?1 if 5% of this land was used and yields were 11.25 odt ha^?1 yr^?1. There are approximately 215,300 odt of forest biomass technically available annually around Tupper Lake from 211,500 ha of timberland. There are 781 ha of technically available agricultural land in this area so willow biomass production would be minimal. While these two areas have different land cover and land use characteristics, both have the potential to produce significant amounts of woody biomass.     

Biomass estimates,characteristics, biochemical methane potential,kinetics and energy flow from Jatropha curcus on dry lands

In this study, we examined the production of Jatropha curcus plants on 1 ha of rain fed dry lands. All of the plant components that would result from plantation tending, fruit harvesting and processing were sampled for their yield and chemical composition, and then subjected to the biochemical methane potential (BMP) assay. The component parts exhibited significant variation in BMP which was reflected in their ultimate methane yield which ranged from 0.08 to 0.97 L g^?1 VS added, and their first order kinetics which ranged from 0.07 to 0.14 d^?1. We examined two integrated utilization schemes: the first which converted plant prunings, fruit hulls and de-oiled seed cake to methane, and the oil to fatty acid methyl-ester (FAME); the second was to convert the seeds, plant prunings and fruit hulls entirely to methane. The basis for the plantation was, a density of 4444 plant ha^?1 (1.5 m × 1.5 m spacing), with a seed yield of 0.911 kg TS plant^?1 (1 kg total weight) with an oil content of 35% providing an annual oil yield of 1.42 t y^?1. The corresponding yields of pruned leaves, fruit hulls and de-oiled cake are 0.97, 1.0, and 2.35 t VS ha y^?1, respectively. An integrated scheme of producing biogas by means of anaerobic digestion of the latter components and oil for biodiesel would produce 90 GJ ha^?1 y^?1 in total with the oil being 54 GJ. The alternative biogas only option which would convert the seed oil into methane instead of biodiesel would produce 97 GJ ha^?1 y^?1.     

Assessment of nitrogen fertilization for the CO2 balance during the production of poplar and rye

This study was designed to consider all nitrogen fertilizer-related effects on crop production and emission of greenhouse gases on loamy sandy soils in Germany over a period of nine years (1999–2007). In order to set up a CO₂ balance for the production of energy crops, different nitrogen pathways were investigated, such as direct N₂O emissions from the soil and indirect emissions related to NO₃ leaching and fertilizer production. Fluxes of N₂O were measured in an experimental field using closed chambers. Poplar (Populus maximowiczii × P. nigra) and rye (Secale cereale L.) as one perennial and one annual crop were fertilized at rates of 0 kg N ha^?1 yr^?1, 75 kg N ha^?1 yr^?1 and 150 kg N ha^?1 yr^?1. The mean N₂O emissions from the soil ranged between 0.5 kg N ha^?1 yr^?1 and 2.5 kg N ha^?1 yr^?1 depending on fertilization rate, crop variety and year. The CO₂ fixed in the biomass of energy crops is reduced by up to 16% if direct N₂O emissions from soil and indirect N₂O emissions from NO₃ leaching and fertilizer production are included. Taking into account the main greenhouse gas emissions, which derive from the production and the use of N fertilizer, the growth of poplar and rye may replace the global warming potential of fossil fuels by up to 17.7 t CO₂ ha^?1 yr^?1 and 12.1 t CO₂ ha^?1 yr^?1, respectively.     

The economical and environmental performance of miscanthus and switchgrass production and supply chains in a European setting

The purpose of this study is to analyse the economical and environmental performance of switchgrass and miscanthus production and supply chains in the European Union (EU25), for the years 2004 and 2030. The environmental performance refers to the greenhouse gas (GHG) emissions, the primary fossil energy use and to the impact on fresh water reserves, soil erosion and biodiversity. Analyses are carried out for regions in five countries. The lowest costs of producing (including storing and transporting across 100 km) in the year 2004 are calculated for Poland, Hungary and Lithuania at 43–64 € per oven dry tonne (odt) or 2.4–3.6 € GJ^?1 higher heating value. This cost level is roughly equivalent to the price of natural gas (3.1 € GJ^?1) and lower than the price of crude oil (4.6 € GJ^?1) in 2004, but higher than the price of coal (1.7 € GJ^?1) in 2004. The costs of biomass in Italy and the United Kingdom are somewhat higher (65–105 € odt^?1 or 3.6–5.8 € GJ^?1). The doubling of the price of crude oil and natural gas that is projected for the period 2004–2030, combined with nearly stable biomass production costs, makes the production of perennial grasses competitive with natural gas and fossil oil. The results also show that the substitution of fossil fuels by biomass from perennial grasses is a robust strategy to reduce fossil energy use and curb GHG emissions, provided that perennial grasses are grown on agricultural land (cropland or pastures). However, in such case deep percolation and runoff of water are reduced, which can lead to overexploitation of fresh water reservoirs. This can be avoided by selecting suitable locations (away from direct accessible fresh water reservoirs) and by limiting the size of the plantations. The impacts on biodiversity are generally favourable compared to conventional crops, but the location of the plantation compared to other vegetation types and the size and harvesting regime of the plantation are important variables.     

Evaluation of integrated harvesting systems in pine stands of the southern United States

We investigated the addition of a small chipper to mechanized, tree-length harvesting systems to produce biomass chips from tops, limbs, and underbrush in planted southern pine stands. The systems were examined in three replicated studies involving clearcuts and thinnings in 2006 and 2007 in the US state of Georgia. Biomass from understory stems ranged from 8.3 to 59.0 green tonnes per hectare in the three studies. Chipping the limbs and tops of merchantable stems did not reduce the production of roundwood, but only produced 7–11 t ha^?1 of biomass. Harvesting understory biomass in addition to chipping limbs and tops worked well with clearcut harvests, but reduced roundwood production by 50% in thinnings. Small chippers added to roundwood operations appear to have limited potential in current market conditions, but should become a viable option as stronger markets for biomass chips develop.     

Management alternatives of energy wood thinning stands

Energy wood thinning has become a feasible treatment alternative of young stands in Finland. Energy wood thinnings have been carried out mainly in stands where precommercial thinning has been neglected and the harvesting conditions for industrial wood thinning are difficult. Despite of its positive effects on harvesting costs and on renewable energy potential, whole-tree harvesting has been constantly criticized for causing growth loss. In this paper, the profitability of energy wood thinning was studied in 20 Scots pine-dominated stands where energy wood thinning was carried out. The growth of the stands after thinning was predicted with the help of Motti-stand simulator. Entire rotation time of the stands was simulated with different management alternatives. The intensity of first thinning and recovery level of logging residues varied between alternatives. In order to attain acceptable harvesting conditions, industrial wood thinning had to be delayed. The effect of energy wood thinning on subsequent stem wood growth was almost the same as in conventional thinning. Whole-tree harvesting for energy proved to be profitable alternative if the stumpage price is around 3€ m⁻³, the interest rate is 3% or 5% and the removal of pulpwood is less than 20 m³ ha⁻¹. If the harvestable pulpwood yield is over 20 m³ ha⁻¹, integrated harvesting of industrial and energy wood or delayed industrial wood harvesting becomes more profitable.     

Utilization of summer legumes as bioenergy feedstocks

Sunn hemp (Crotolaria juncea), is a fast growing, high biomass yielding tropical legume that may be a possible southeastern bioenergy crop. When comparing this legume to a commonly grown summer legume – cowpeas (Vigna unguiculata), sunn hemp was superior in biomass yield (kg ha^?1) and subsequent energy yield (GJ ha^?1). In one year of the study after 12 weeks of growth, sunn hemp had 10.7 Mg ha^?1 of biomass with an energy content of 19.0 Mg ha^?1. This resulted in an energy yield of 204 GJ ha^?1. The energy content was 6% greater than that of cowpeas. Eventhough sunn hemp had a greater amount of ash, plant mineral concentrations were lower in some cases of minerals (K, Ca, Mg, S) known to reduce thermochemical conversion process efficiency. Pyrolytic degradation of both legumes revealed that sunn hemp began to degrade at higher temperatures as well as release greater amounts of volatile matter at a faster rate.     

Economics of poplar short rotation coppice plantations on marginal land in Germany

Although there is a need for biomass and a potential for short rotation coppice (SRC), farmers hesitate to establish SRC, even on marginal agricultural land on which annual crops show low productivity. Probably the most important factor explaining this reluctance might be the uncertain economic prospects of the cultivation of SRC. Therefore, the aim of this study is to analyse the economy of a typical SRC supply chain by calculating the annuities which can be expected by German farmers who establish SRC on their marginal land.The result shows that the yearly annuity of a 20-year SRC cultivation is about 70 € y⁻¹ ha⁻¹ when poplar SRC is harvested every 4 years with a forage harvester (one-step system). The result includes the establishment, cultivation and transport of the fresh wood chips to a plant 50 km away. However, this result is not competitive with the result of annual crops (226–462 € y⁻¹ ha⁻¹) and is also lower than the CAP subsidy payments that farmers receive from the EU (300 € y⁻¹ ha⁻¹). To achieve higher annuities, four options were analysed possibly leading either to higher biomass yields or to higher market prices (extension of rotation cycle, implementation of irrigation, technical drying of fresh wood chips, using a two-step harvesting system). The implementation of drip irrigation to increase biomass yield turned out to be uneconomic. An extension of the rotation cycle from 4 to 5 years can be recommended as it leads to an annuity of 255 € y⁻¹ ha⁻¹ (instead of 69 € y⁻¹ ha⁻¹). Results also show that the technical drying of chips using (cheap) surplus heat can be very profitable if the added value is reflected in higher market prices. Furthermore, it is shown that the use of an alternative two-step harvesting system with natural interim drying of the rods can be an attractive option for farmers to increase the annuity of their SRC.     

Kudzu [Pueraria montana (Lour.) Merr. Variety lobata]: A new source of carbohydrate for bioethanol production

We determined the amount of standing biomass of kudzu (Pueraria montana var lobata) in naturally infested fields in Maryland and Alabama, USA. At each site, we evaluated the carbohydrate content of roots, stems, and leaves. For a third site from Georgia, we evaluated the carbohydrate content of kudzu roots of varying diameters. Belowground biomass in Alabama exceeded 13 t ha^?1, and contained an average of 37% fermentable carbohydrates (sucrose, glucose, and starch). Roots from Georgia of all size classes contained over 60% fermentable carbohydrates. Biomass and carbohydrate levels in roots from Maryland were low compared to plants growing in Alabama and Georgia, producing 5 t ha^?1 of roots with 20% non-structural carbohydrate. Stems from Alabama and Maryland contained 1–3% carbohydrates. Based on the yield and carbohydrate content, we estimate wild kudzu stands in Alabama and Georgia could produce 5–10 t ha^?1 of carbohydrate, which would rival carbohydrate production from maize and sugar cane fields. If economical harvesting and processing techniques could be developed, the kudzu infesting North America has the potential to supplement existing bioethanol feedstocks, which could be of significance to the rural economy of the southeastern USA.     

European biomass resource potential and costs

The objective of this study is to assess the European (EU27⁺ and Ukraine) cost and supply potential for biomass resources. Three methodological steps can be distinguished (partly based on studies explained elsewhere in this volume) (i) an evaluation of the available ‘surplus’ land, (ii) a modeled productivity and (iii) an economic assessment for 13 typical bioenergy crops. Results indicate that the total available land for bioenergy crop production – following a ‘food first’ paradigm – could amount to 900 000 km² by 2030. Three scenarios were constructed that take into account different development directions and rates of change, mainly for the agricultural productivity of food production. Feedstock supply of dedicated bioenergy crop estimates varies between 1.7 and 12.8 EJ y^?1. In addition, agricultural residues and forestry residues can potentially add to this 3.1–3.9 EJ y^?1 and 1.4–5.4 EJ y^?1 respectively. First generation feedstock supply is available at production costs of 5–15 € GJ^?1 compared to 1.5–4.5 € GJ^?1 for second generation feedstocks. Costs for agricultural residues are 1–7 € GJ^?1 and forestry residues 2–4 € GJ^?1. Large variation exists in biomass production potential and costs between European regions, 280 (NUTS2) regions specified. Regions that stand out with respect to high potential and low costs are large parts of Poland, the Baltic States, Romania, Bulgaria and Ukraine. In Western Europe, France, Spain and Italy are moderately attractive following the low cost high potential criterion.     

Economics of switchgrass and miscanthus relative to coal as feedstock for generating electricity

Switchgrass (Panicum virgatum) serves as a model dedicated energy crop in the U.S.A. Miscanthus (Miscanthus x giganteus) has served a similar role in Europe. This study was conducted to determine the most economical species, harvest frequency, and carbon tax required for either of the two candidate feedstocks to be an economically viable alternative for cofiring with coal for electricity generation. Biomass yield and energy content data were obtained from a field experiment conducted near Stillwater, Oklahoma, U.S.A., in which both grasses were established in 2002. Plots were split to enable two harvest treatments (once and twice yr^?1). The switchgrass variety ‘Alamo’, with a single annual post-senescence harvest, produced more biomass (15.87 Mg ha^?1 yr^?1) than miscanthus (12.39 Mg ha^?1 yr^?1) and more energy (249.6 million kJ ha^?1 yr^?1 versus 199.7 million kJ ha^?1 yr^?1 for miscanthus). For the average yields obtained, the estimated cost to produce and deliver biomass an average distance of 50 km was $43.9 Mg^?1 for switchgrass and $51.7 Mg^?1 for miscanthus. Given a delivered coal price of $39.76 Mg^?1 and average energy content, a carbon tax of $7 Mg^?1 CO₂ would be required for switchgrass to be economically competitive. For the location and the environmental conditions that prevailed during the experiment, switchgrass with one harvest per year produced greater yields at a lower cost than miscanthus. In the absence of government intervention such as requiring biomass use or instituting a carbon tax, biomass is not an economically competitive feedstock for electricity generation in the region studied.     

The impact of sustainability criteria on the costs and potentials of bioenergy production – Applied for case studies in Brazil and Ukraine

The goal of this paper is to analyse the impact of the implementation of a certification system on the management system (costs) of and the availability of land (quantity) for bioenergy production. Twelve socio-economic areas of concern (food supply, child labour, (minimum) wages, employment, health care and education) and environmental areas of concern (soil erosion, depletion of fresh water resources, nutrient losses and soil nutrient depletion, pollution from chemicals and biodiversity) are included. Since there is no generally accepted definition of sustainability, a loose and strict set of criteria are defined. Short rotation coppice (SRC) production systems in Ukraine and South East Brazil in 2015 are taken as case studies. The results indicate that it seems feasible to produce biomass for energy purposes at reasonable cost levels and meeting strict sustainability criteria at the same time. The loose set of criteria has no impact on the costs of energy crop production, which are calculated to be 1.7 € GJ^?1 in Brazil and 2.1 € GJ^?1 in Ukraine. The strict set of criteria results in an increase of the costs of energy crop production by 42 % in Brazil and 14 % in Ukraine. In general, compliance with strict socio-economic criteria has a limited impact on the costs, because SRC is relatively labour extensive. Strict environmental criteria likely have a larger impact.     

An analysis of energy use and relation between energy inputs and yield in tangerine production

The objective of this study is to determine energy balance between inputs and output for tangerine production in Mazandaran province, one of the most important citrus production centers in Iran. Data is collected by administering a questionnaire in face-to-face interviews. The results show that the highest share of energy was utilized by application of chemical fertilizers and chemicals. Average yield and energy consumption are calculated as 26862.5 kg ha^?1 and 62260.9 MJ ha^?1, respectively. The energy productivity and net energy value are estimated as 0.43 kg MJ^?1 and ?8201.4 MJ ha^?1, respectively. The ratio of energy outputs to energy inputs is approximately 0.87. In addition, the Cobb–Douglas production function is applied to estimate the econometric relationship among different forms of energy consumption. The findings suggest that tangerine producers must optimize their use of indirect and non-renewable energy resources; they apply an excess use of some energy inputs, resulting in an inverse effect on yield as well as imposing risks to natural resources and human health.     

Comparison of Arundo donax L. and Miscanthus x giganteus in a long-term field experiment in Central Italy: Analysis of productive characteristics and energy balance

Miscanthus x giganteus (miscanthus) and Arundo donax L. (giant reed) are two perennial crops which have been received particular attention during the last decade as bioenergy crops. The main aim of the present study was to compare the above-ground biomass production and the energy balance of these perennial rhizomatous grasses in a long-term field experiment. The crops were cultivated from 1992 to 2003 in the temperate climate of Central Italy with 20,000 plants ha^?1, 100–100–100 kg N, P₂O₅, K₂O per hectare, and without irrigation supply. For each year of trial, biomass was harvested in autumn to estimate biometric characteristics and productive parameters. Besides, energy analysis of biomass production was carried out determining energy output, energy input, energy efficiency (output/input) and net energy yield (output–input). Results showed high above-ground biomass yields over a period of 10 years for both species, with better productive performances in giant reed than in miscanthus (37.7 t DM ha^?1 year^?1 vs 28.7 t DM ha^?1 year^?1 averaged from 2 to 12 years of growth). Such high yields resulted positively correlated to number of stalks (miscanthus), plant height and stalk diameter (giant reed). Moreover, these perennial species are characterised by a favourable energy balance with a net energy yield of 467 and 637 GJ ha^?1 (1–12 year mean) for miscanthus and giant reed respectively.With such characteristics, both grasses could be proposed as biomass energy crops in Southern Europe with a significant and environmentally compatible contribution to energy needs.     

Engineering,nutrient removal,and feedstock conversion evaluations of four corn stover harvest scenarios

Crop residue has been identified as a near-term source of biomass for renewable fuel, heat, power, chemicals and other bio-materials. A prototype one-pass harvest system was used to collect residue samples from a corn (Zea mays L.) field near Ames, IA. Four harvest scenarios (low cut, high-cut top, high-cut bottom, and normal cut) were evaluated and are expressed as collected stover harvest indices (CSHI). High-cut top and high-cut bottom samples were obtained from the same plot in separate operations. Chemical composition, dilute acid pretreatment response, ethanol conversion yield and efficiency, and thermochemical conversion for each scenario were determined. Mean grain yield in this study (10.1 Mg ha⁻¹ dry weight) was representative of the average yield (10.0 Mg ha⁻¹) for the area (Story County, IA) and year (2005). The four harvest scenarios removed 6.7, 4.9, 1.7, and 5.1 Mg ha⁻¹ of dry matter, respectively, or 0.60 for low cut, 0.66 for normal cut, and 0.61 for the total high-cut (top+bottom) scenarios when expressed as CSHI values. The macro-nutrient replacement value for the normal harvest scenario was $57.36 ha⁻¹ or $11.27 Mg⁻¹. Harvesting stalk bottoms increased stover water content, risk of combine damage, estimated transportation costs, and left insufficient soil cover, while also producing a problematic feedstock. These preliminary results indicate harvesting stover (including the cobs) at a height of approximately 40 cm would be best for farmers and ethanol producers because of faster harvest speed and higher quality ethanol feedstock.     

A full economic analysis of switchgrass under different scenarios in Italy estimated by BEE model

Three different scenarios of switchgrass (Panicum virgatum L.) cultivation (high, mild and low) in two different environmental conditions (North and South Italy) were economically analysed by the computerized model BEE. The dataset was mostly generated from an 8.6 ha field of switchgrass planted in 2002 at the University of Bologna (North Italy). Annual equivalent costs (AEC) and break-even yield (BEY, i.e. the dry matter yield at which cost equals selling price) of each scenario were calculated to assess the feasibility of each scenario. AEC ranged from €511 to €1.257 ha⁻¹ being always higher in northern than southern regions. As expected, BEY varied to an extent depending on input levels. BEY was clearly higher under intensive cropping systems (H_S) compared to mild-(M_S) and low-input (L_S) scenarios. However, even for M_S or L_S, BEY generally exceeded the harvested yield. Therefore, we can conclude that, at the market price of €55 Mg⁻¹ (dry basis), switchgrass can be hardly grown both in North and South Italy. However, the biomass market price appeared surprisingly underestimated if compared to the unit energy price of crude oil, therefore a desirable increase of biomass price could be expected in the next few years. Sensitivity analysis showed that biomass price strongly affects BEY, and this was especially found in H_S. Furthermore, the differences in BEY between L_S and H_S clearly decreased with increasing market prices. Therefore, H_S could be better indicated than L_S at high market prices. Switchgrass was found to be more profitable than some conventional crops to an extent depending on the yield higher than BEY (Y_i). At the current biomass price, Y_i was from less than 1 Mg ha⁻¹ (maize and alfalfa) to more than 4 Mg ha⁻¹ (sugarbeet).