A case study of energy use and economical analysis of irrigated and dryland wheat production systems

Current conventional agricultural systems using intensive energy has to be re-vitalized by new integrated approaches relying on renewable energy resources, which can allow farmers to stop depending on fossil resources. The aim of the present study was to compare wheat production in dryland (low input) and irrigated (high input) systems in terms of energy ratio, energy efficiency, benefit/cost ratio and amount of renewable energy use. Data were collected from 50 irrigated and 50 dryland wheat growers by using a face-to-face questionnaire in 2009. The results showed that the total energy requirement under low input was 9354.2 MJ ha⁻¹, whereas under high input systems it was 45367.6 MJ ha⁻¹. Total energy input consumed in both dryland and irrigated systems could be classified as direct, indirect, renewable and non-renewable energies which average in two wheat production systems were 47%, 53%, 24% and 76%, respectively. Energy ratios of 3.38 in dryland and 1.44 in irrigated systems were achieved. The benefit–cost ratios were 2.56 in dryland and 1.97 in irrigated wheat production systems. Based on the results of the present study, dry-land farming can have a significant positive effect on energy-related factors especially in dry and semi-dry climates such as Iran.     

Optimizing biofuel production: An economic analysis for selected biofuel feedstock production in Hawaii

Hawaii’s agricultural sector has an immense supply of natural resources that can be further developed and utilized to produce biofuel. Transformation of the renewable and abundant biomass resources into a cost competitive, high performance biofuel could reduce Hawaii’s dependence on fossil fuel importation and enhance energy security. The objectives of the study are to evaluate the economic feasibility of selected bioenergy crops for Hawaii and compare their cost competitiveness. The selected feedstock consists of both ethanol and biodiesel producing crops. Ethanol feedstock includes sugar feedstock (sugarcane) and lignocellulosic feedstock (banagrass, Eucalyptus, and Leucaena). Biodiesel feedstock consists of Jatropha and oil palm.The economic analysis is divided into two parts. First, a financial analysis was used to select feasible feedstock for biofuel production. For each feedstock, net return, feedstock cost per Btu, feedstock cost per gallon of ethanol/biodiesel, breakeven price of feedstock and breakeven price of ethanol/biodiesel were calculated. Leucaena shows the lowest feedstock cost per Btu while banagrass has the highest positive net returns in terms of both feedstock price and energy price.The second approach assumes an objective of maximizing net returns. Given this assumption, biofuel producers will produce only banagrass. As an example, the production of bioenergy on the island of Hawaii is illustrated where 74,793 acres of non-prime land having a “warm and moist” soil temperature and moisture regime are available. Using average yields (static optimization), banagrass production on this acreage can yield 8.24 trillion Btus of energy (ethanol). This satisfies the State’s 10% self-sufficiency energy goal of 3.9 trillion Btus by 2010. Incorporating risk through variability in crop yields and biofuel prices separately shows banagrass as having the highest probability for receiving a positive net return. Banagrass is the leading candidate crop for biofuel production in Hawaii and the State of Hawaii ethanol goal can be achieved by allocating non-prime lands for banagrass production without compromising prime lands currently allocated for agricultural food production in Hawaii. Physical, environmental and socio-economic impacts should be accounted for in evaluating future biofuel projects.     

An economic analysis of biochar production using residues from Eucalypt plantations

Producing biochar from organic residues is a potential method to integrate carbon sequestration and residue management costs while enhancing conventional agricultural and forestry production systems. Plantation forestry is an important industry in Tasmania, and is based on large scale plantations of Pinus radiata and Eucalyptus (Eucalyptus globulus and E. nitens). The area covered by forestry plantations in Tasmania (on State land) exceeds 100 000 ha, while plantations on private land double this number. Eucalypt plantations are managed primarily for the production of high-value pruned logs for industry; however, unpruned saw logs, peelers, poles, posts and pulp are also produced, and significant quantities of residue are produced as a byproduct. This study was an economic analysis that considered on-site biochar production system using post-harvest forestry residues, with biochar being utilized within the system, or sold as a product. The financial analysis was based on previous experimental outcomes on the use of Macadamia shell biochar in Eucalyptus nitens plantations, and the local operating environment in Tasmania; including current forestry procedures used for managing plantations. A number of assumptions were considered concerning a) production costs, b) savings enjoyed by traditional operations, following biochar scenario implementation, and c) biochar sales. The analysis revealed a potential annual income of over 179 k$ (2014 value) and the sensitivity analysis identified the crucial factors responsible for scenario profitability, namely biochar price and final product distribution.     

An economic analysis comparison of stationary and dual-axis tracking grid-connected photovoltaic systems in the US Upper Midwest

This paper presents an economic analysis of stationary and dual-axis tracking photovoltaic (PV) systems installed in the US Upper Midwest in terms of life-cycle costs, payback period, internal rate of return, and the incremental cost of solar energy. The first-year performance and energy savings were experimentally found along with documented initial cost. Future PV performance, savings, and operating and maintenance costs were estimated over 25-year assumed life. Under the given assumptions and discount rates, the life-cycle savings were found to be negative. Neither system was found to have payback periods less than the assumed system life. The lifetime average incremental costs of energy generated by the stationary and dual-axis tracking systems were estimated to be $0.31 and $0.37 per kWh generated, respectively. Economic analyses of different scenarios, each having a unique set of assumptions for costs and metering, showed a potential for economic feasibility under certain conditions when compared to alternative investments with assumed yields.     

An economic analysis and energy use in stake-tomato production in Tokat province of Turkey

The aim of this study is to determine the input–output energy consumption and to make a cost analysis of intermediate type stake-tomato grown in open field in Tokat province of Turkey. The data used in the study were obtained from 98 local tomato growers using a questionnaire. The farms were chosen by random sampling method. The results showed that the amount of energy consumed in stake-tomato production was 96 957.36 MJ ha⁻¹. About 42% of this was generated by diesel oil and 38% from fertilizers and machinery. The input–output ratio was 0.80 and energy productivity was found to be 1.00 kg MJ ha⁻¹. About 76% of the total energy inputs used in stake-tomato production was non-renewable while only about 22% was renewable. These findings reveal that intensive input use in stake-tomato production, especially chemical fertilizers, gives a high tomato yield but also raises some problems like environmental pollution and global warming. Thus, new policies, emphasizing energy consumption without degradation of national resources, should be designed for such farms.     

Process design and economic evaluation for the production of glucose from enzymatic hydrolysis of acid pretreated mixed hardwood

A basic process plant design is presented which has a production capacity of 1060 tons of glucose per day. The processing scheme for converting mixed hardwood to glucose consists of a mild acid hydrolysis pretreatment of the substrate in a continuous plug flow reactor, followed by enzymatic hydrolysis in a batch stirred reactor. As the slurry concentration varies from 10 to 20 percent in the enzymatic hydrolysis, the glucose yields change from 91.4 to 74 percent, respectively. The costs of producing glucose per pound in an aqueous solution with a substrate cost of 2¢/1b are given for each design and range from 13 to 16¢/1b. Since the concentration of glucose is different in each design, an additional cost of bringing each design to at least 10 percent glucose is given. A cost sensitivity study is presented. Also, the cost of straight acid hydrolysis with 56 percent glucose yield is compared to this 2-stage process.     

An economic analysis of the production of hydrogen from wind-generated electricity for use in transport applications

Wind-generated electricity is often considered a particularly promising option for producing hydrogen from renewable energy sources. However, the economic performances of such systems generally remain unclear because of unspecified or favorable assumptions and operating conditions. The aim of this paper is to clarify these conditions by examining how the hydrogen produced is used. The analysis that has been conducted in the framework of the HyFrance 3 project concerns hydrogen for transport applications. Different technical systems are considered such as motorway hydrogen filling stations, Hythane®-fueled buses or second-generation biofuels production, which present contrasted hydrogen use characteristics. This analysis reveals considerable variations in hydrogen production costs depending on the demand profiles concerned, with the most favorable configurations being those in which storage systems are kept to a minimum.     

An economic analysis of energy requirements and input costs for tomato production in Turkey

The aim of this study was to examine direct and indirect input energy in per hectare in tomato (industrial type) production and compare it with production costs. The research also sought to analyse the effect of farm size. For this purpose, the data were collected from 95 tomato farmers by questionnaire method. The results indicated that tomato production consumed a total of 45.53 GJ ha⁻¹ of which diesel energy consumption was 34.82% followed by fertilizer and machinery energy. Output–input energy ratio and energy productivity were found to be 0.80 and 0.99 kg of tomato MJ⁻¹, respectively. Cost analysis revealed that the most important cost items were labour costs, machinery costs, land rent and pesticide costs. According to the benefit–cost ratio, large farms were more successful in energy use and economic performance. It was concluded that energy use management at farm level could be improved to give more efficient and economic use of energy.     

Biohydrogen production: An outlook on methods,constraints, economic analysis and future prospect

Utilization of hydrogen as fuel lights into various technological, economic and ecological challenges. High production cost and low yield are main drawbacks of commercial hydrogen production methods. Hydrogen production by biological methods helps to overcome these issues owing to its merit such as cost-effective, non-pollutant, recyclability and efficiency in energy conversion. Research has been conducted in utilizing cyanobacteria and algal species for producing biohydrogen utilizing solar light and other sources. Developments have been made for improving biohydrogen productivity through genetic and metabolic engineering. This review outlines the importance of biohydrogen and the constraints in producing biohydrogen in detail. Biohydrogen production can be facilitated using photolysis, fermentation and electrochemical processes. Bioreactors can be used effectively with specific designs and configuration for increasing productivity. The challenges faced during biological production and methods to overcome those demerits are also included for bringing the uncharted principles for producing biohydrogen in an efficient method.     

An economic assessment of potential ethanol production pathways in Ireland

An economic assessment was conducted on five biomass-to-ethanol production pathways utilising the feedstock: wheat, triticale, sugarbeet, miscanthus and straw. The analysis includes the costs and margins for all the stakeholders along the economic chain. This analysis reveals that under current market situations in Ireland, the production of ethanol under the same tax regime as petrol makes it difficult to compete against that fuel, with tax breaks, however, it can compete against petrol. On the other hand, even under favourable tax breaks it will be difficult for indigenously produced ethanol to compete against cheaper sources of imported ethanol. Therefore, the current transport fuel market has no economic reason to consume indigenously produced ethanol made from the indigenously grown feedstock analysed at a price that reflects all the stakeholders’ costs. To deliver a significant penetration of indigenous ethanol into the market would require some form of compulsory inclusion or else considerable financial supports to feedstock and ethanol producers.     

An economic analysis of the financial viability of switchgrass as a raw material for pulp production in eastern Ontario

This paper examines the economic viability of producing switchgrass (Panicum virgatum) to be used as pulp in fine paper production. Pulp mills in eastern Ontario and western Quebec are considered to be the potential market for switchgrass. The potential size of the market for switchgrass pulp is assessed. Budgets for switchgrass are constructed and various measures of the potential market value of switchgrass are calculated. Based on these preliminary findings, it appears that switchgrass could be an attractive crop for farmers in eastern Ontario and western Quebec. The total land area required to satisfy the potential demand for switchgrass fibre for pulping in eastern Ontario is estimated to be between 22,000 and 48,000 hectares. Further agronomic research to examine the productivity of switchgrass on economically marginal and erosion prone lands is indicated.     

Energy requirement and economic analysis of citrus production in Turkey

The aim of this research was to examine the energy requirements of the inputs and output in citrus production in the Antalya province of Turkey. Data for the production of citrus fruits (orange, lemon and mandarin) were collected from 105 citrus farms by using a face to face questionnaire method. The research results revealed that lemon production was the most energy intensive among the three fruits investigated. The energy input of chemical fertilizer (49.68%), mainly nitrogen, has the biggest share in the total energy inputs followed by Diesel (30.79%). The lemon production consumed a total of 62 977.87 MJ/ha followed by orange and mandarin with 60 949.69 and 48 838.17 MJ/ha, respectively. The energy ratios for orange, mandarin and lemon were estimated to be 1.25, 1.17 and 1.06, respectively. On average, the non-renewable form of energy input was 95.90% of the total energy input used in citrus production compared to only 3.74% for the renewable form. The benefit–cost ratio was the highest in orange production (2.37) followed by lemon. The results indicate that orange production in the research area is most remunerative to growers compared to lemon and mandarin.     

Biomass system model estimates of short-rotation hardwood production in Hawaii

By coupling a short-rotation, intensive-culture (SRIC) biomass production model with a geographical information system and database, potential biomass supply (dry Mg) and delivered cost ($(dry Mg)⁻¹) of three promising tropical hardwoods, Eucalyptus grandis, E. saligna, and Leucaena leucocephala, were estimated at all locations identified as potentially available for tree plantations on the island of Maui. Analyses were performed at two scales-island-wide (10⁵ ha order of magnitude) for general land-use planning, and specific-site (10² ha order of magnitude) for field-level recommendations. The results are presented as yield and delivered cost maps and biomass supply curves for the entire island, and as management strategies depicted graphically as functions of growing space and rotation age that provide least-cost biomass feedstocks delivered from two specific field sites to a designated bioconversion facility on Maui. The methodology is a cost- and time-efficient means to provide useful information to land owners and other decision makers contemplating SRIC forestry as an alternative land use.     

生产燃料乙醇的主要原料及经济性分析

目前,国际上制造燃料乙醇的原料分为三种:玉米、小麦等粮食作物;红薯、木薯、甜高梁等非粮作物;农作物秸秆、林业加工废料、甘蔗渣及城市垃圾中所含的废弃物,统称为纤维素类原料.其中,技术最成熟的是以玉米、小麦和甘蔗为原料生产燃料乙醇,巴西和美国已经有大规模的制造基地.     

Understanding the reductions in US corn ethanol production costs: An experience curve approach

The US is currently the world's largest ethanol producer. An increasing percentage is used as transportation fuel, but debates continue on its costs competitiveness and energy balance. In this study, technological development of ethanol production and resulting cost reductions are investigated by using the experience curve approach, scrutinizing costs of dry grind ethanol production over the timeframe 1980–2005. Cost reductions are differentiated between feedstock (corn) production and industrial (ethanol) processing. Corn production costs in the US have declined by 62% over 30 years, down to 100$₂₀₀₅/tonne in 2005, while corn production volumes almost doubled since 1975. A progress ratio (PR) of 0.55 is calculated indicating a 45% cost decline over each doubling in cumulative production. Higher corn yields and increasing farm sizes are the most important drivers behind this cost decline. Industrial processing costs of ethanol have declined by 45% since 1983, to below 130$₂₀₀₅/m³ in 2005 (excluding costs for corn and capital), equivalent to a PR of 0.87. Total ethanol production costs (including capital and net corn costs) have declined approximately 60% from 800$₂₀₀₅/m³ in the early 1980s, to 300$₂₀₀₅/m³ in 2005. Higher ethanol yields, lower energy use and the replacement of beverage alcohol-based production technologies have mostly contributed to this substantial cost decline. In addition, the average size of dry grind ethanol plants increased by 235% since 1990. For the future it is estimated that solely due to technological learning, production costs of ethanol may decline 28–44%, though this excludes effects of the current rising corn and fossil fuel costs. It is also concluded that experience curves are a valuable tool to describe both past and potential future cost reductions in US corn-based ethanol production.     

An economic welfare analysis of demand response in the PJM electricity market

We analyze the economic properties of the economic demand-response (DR) program in the PJM electricity market in the United States using DR market data. PJM's program provided subsidies to customers who reduced load in response to price signals. The program incorporated a “trigger point”, at a locational marginal price of $75/MWh, at or beyond which payments for load reduction included a subsidy payment. Particularly during peak hours, such a program saves money for the system, but the subsidies involved introduce distortions into the market. We simulate demand-side bidding into the PJM market, and compare the social welfare gains with the subsidies paid to price-responsive load using load and price data for year 2006. The largest economic effect is wealth transfers from generators to non price-responsive loads. Based on the incentive payment structure that was in effect through the end of 2007, we estimate that the social welfare gains exceed the distortions introduced by the subsidies. Lowering the trigger point increases the transfer from generators to consumers, but may result in the subsidy outweighing the social welfare gains due to load curtailment. We estimate that the socially optimal range for the incentive trigger point would be $66–77/MWh.     

新型纤维素乙醇原料保障体系及经济分析

为解决北方某纤维素乙醇生产企业的原料收储问题,文中基于该地区特点提出以农业剩余物固体成型为核心的新型原料收储路线,并初步设计整个原料保障体系运作方式;同时根据建立的收储经济评价模型,对新旧原料收储路线下纤维素乙醇原料的收储运及生产过程进行经济分析,探讨了燃料乙醇规模扩张时的盈利情况以及影响因素。分析结果表明,新型收储路线大幅度简化了原料收储方式,具有运输半径合理、存储条件要求低、潜在效益较佳等优势,适宜于保障规模化燃料乙醇的生产。     

Solar cooling technologies in Greece. An economic viability analysis

In Greece, during the summer, the demand for electricity greatly increases because of the extensive use of air-conditioning systems. This is a source of major problems in the country’s electricity supply and contributes to an increase of the CO₂ emissions. The use of solar energy (SE) to drive cooling cycles is attractive since the cooling load is roughly in phase with SE availability. An economic evaluation of two types of solar cooling systems is made (an absorption and an adsorption system). The analyses indicated that, because of their high investment cost, these systems would be marginally competitive with standard cooling systems at present energy prices.     

An integrated economic and distributional analysis of energy policies

Most public policies, particularly those in the energy sphere, have not only efficiency but also distributional effects. However, there is a trade-off between modelling approaches suitable for calculating those impacts on the economy. For the former most of the studies have been conducted with general equilibrium models, whereas partial equilibrium models represent the main approach for distributional analysis. This paper proposes a methodology to simultaneously carry out an analysis of the distributional and efficiency consequences of changes in energy taxation. In order to do so, we have integrated a microeconomic household demand model and a computable general equilibrium model for the Spanish economy. We illustrate the advantages of this approach by simulating a revenue-neutral reform in Spanish indirect taxation, with a large increase of energy taxes that serve an environmental purpose. The results show that the reforms bring about significant efficiency and distributional effects, in some cases counterintuitive, and demonstrate the academic and social utility of this approximation.     

Revising the potential of large-scale Jatropha oil production in Tanzania: An economic land evaluation assessment

Following up the rather sobering results of the biofuels boom in Tanzania, we analyze the preconditions that would make large-scale oil production from the feedstock Jatropha curcas viable. We do this by employing an economic land evaluation approach; first, we estimate the physical land suitability and the necessary inputs to reach certain amounts of yields. Subsequently, we estimate costs and benefits for different input-output levels. Finally, to incorporate the increased awareness of sustainability in the export sector, we introduce also certification criteria. Using data from an experimental farm in Kilosa, we find that high yields are crucial for the economic feasibility and that they can only be obtained on good soils at high input rates. Costs of compliance with certification criteria depend on site specific characteristics such as land suitability and precipitation. In general, both domestic production and (certified) exports are too expensive to be able to compete with conventional diesel/rapeseed oil from the EU. Even though the crop may have potential for large scale production as a niche product, there is still a lot of risk involved and more experimental research is needed.