Energy use patterns and econometric models of grape production in Hamadan province of Iran

This paper examines the energy use patterns and relationship between energy input and yield for grape production in Malayer region of Hamadan Province. Data from 50 farmers were collected using a face-to-face questionnaire method. In the surveyed vineyards, average yield and energy consumption were calculated as 18,530 kgha⁻¹ and 45,213.66 MJha⁻¹, respectively. Among input energy sources, fertilizers, electricity and farmyard manure contained highest energy shares with 37.25%, 19%, and 17.84%, respectively. The energy ratio and energy productivity were found to be 4.95 and 0.42 kgMJ⁻¹.Three econometric models were developed to estimate the impact of energy inputs on yield. The results revealed that impact of chemical, fertilizer and water on yield were significant at 1% probability level. Also, indirect and non-renewable energies were found to be rather high. Sensitivity analysis indicated that among the inputs, chemical has the highest MPP value of energy inputs. RTS (returns to scale) values for grape yield was found to be 2.15; thus, there prevailed an IRS of grape for estimated model. The net return was found to be positive as 2810.56 $ha⁻¹ for grape. The benefit-cost ratio was calculated as 2.08.     

A comparative study on energy use and cost analysis of potato production under different farming technologies in Hamadan province of Iran

The aim of this study was to determine the amount of input–output energy used in potato production and to make an economic analysis of potato production in Hamadan province, Iran. Data for the production of potatoes were collected from 100 producers by using a face to face questionnaire method. The population investigated was divided into two groups. Group I was consisted of 68 farmers (owner of machinery and high level of farming technology) and Group II of 32 farmers (non-owner of machinery and low level of farming technology). The results revealed that 153071.40 MJ ha⁻¹ energy consumed by Group I and 157151.12 MJ ha⁻¹ energy consumed by Group II. The energy ratio, energy productivity, specific energy, net energy gain and energy intensiveness were calculated. The net energy of potato production in Group I and Group II was 4110.95 MJ ha⁻¹ and −21744.67 MJ ha⁻¹, respectively. Cost analysis showed that total cost of potato production in Groups I and II were 4784.68 and 4172.64 $ ha⁻¹, respectively. The corresponding, benefit to cost ratio from potato production in the surveyed groups were 1.09 and 0.96, respectively. It was concluded that extension activities are needed to improve the efficiency of energy consumption in potato production.     

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.     

Energy use patterns and econometric models of major greenhouse vegetable productions in Iran

This paper examines the energy use patterns and energy input-output analysis of major greenhouse vegetable productions in Iran. Data from 43 farmers were obtained using a face-to-face questionnaire method. The majority of farmers in the surveyed region were growing cucumber and tomato. Total input energy was found to be 141493.51 and 131634.19 MJ ha⁻¹ for cucumber and tomato productions, respectively. Among input energy sources, diesel fuel and fertilizers contained highest energy with 54.17-49.02% and 21.64-24.01%, respectively. The energy ratio was found to be 0.69 and 1.48 for cucumber and tomato productions, respectively. Econometric model evaluation showed the impact of human labor for cucumber and chemicals for tomato was significant at 1% levels. Sensitivity analysis indicated that the MPP value of energy inputs were between −5.87 and 7.74. RTS (returns to scale) values for cucumber and tomato yields were found to be 1.29 and 0.76; thus, there prevailed an IRS of cucumber for estimated model. The net return was found positive, as 22651.13 and 78125.08 $ ha⁻¹ for cucumber and tomato, respectively. The benefit-cost ratios from cucumber and tomato productions were calculated to be 1.68 and 3.28, respectively. Among the surveyed greenhouses, the result indicated tomato cultivation was more profitable.     

Energy use and economical analysis of sugar beet production in Tokat province of Turkey

The purposes of this study were to determine energy consumption of input and output used in sugar beet production, and to make a cost analysis in Tokat, Turkey. Data were collected from 146 sugar beet farms in Tokat, Turkey by using a face-to-face questionnaire performed in January and February 2005. Farms were selected based on random sampling method. The results revealed that total energy consumption in sugar beet production was 39 685.51 MJ ha⁻¹, and accounted for 49.33% of fertilizer energy, and 24.16% of diesel energy. The output/input energy ratio was 25.75 and energy productivity was 1.53 kg MJ ha⁻¹. Results further indicated that 82.43% of total energy input was in non-renewable energy form, and only 12.82% was in renewable form. Economic analyses showed that profit–cost ratio of farms was 1.17. The highest energy cost items were labor, land renting, depreciation and fertilizers. Although intensive energy consumption in sugar beet production increased the yield, it also resulted in problems such as global warming, land degradation, nutrient loading and pesticide pollution. Therefore, there is a need to pursue a new policy to force producers to undertake energy-efficient practices to establish sustainable production systems without disrupting the natural resources. In addition, extension activities are needed to improve the efficiency of energy consumption and to sustain the natural resources.     

Modeling and sensitivity analysis of energy inputs for apple production in Iran

This study was conducted to determine the energy balance between the energy inputs and yield for apple production in Tehran, Iran. For this purpose the data were collected from 56 apple orchards. The following results were obtained from this study: The total energy input of 42819.25 MJ ha⁻¹ was required for apple production. The share of diesel fuel by 21.88% of the total energy inputs was the highest energy input. This was followed by farmyard manure (17.66%) and electricity (13.09%), respectively. The energy use efficiency, energy productivity, Specific energy, and net energy were found as 1.16, 0.49 kg MJ⁻¹, 2.06 MJ kg⁻¹ and 7038.18 MJ ha⁻¹, respectively. According to the research results, the contribution of direct energy was higher than that of indirect energy; also the share of non-renewable energy was more than that of renewable energy. The results of econometric model estimation revealed that the impact of farmyard manure, water for irrigation, electricity, chemical fertilizer and human labour energy inputs were significantly positive on yield. The results of sensitivity analysis of the energy inputs showed that the MPP value of water for irrigation was the highest, followed by human labour and chemicals energy inputs, respectively.     

Technical and economic feasibility study of using Micro CHP in the different climate zones of Iran

The growing worldwide demand for less polluting shapes of energy have led to a renewed interest in the use of Micro Combined Heat and Power (Micro CHP) technologies in the residential sector. Micro CHP have been introduced around Iran recently, and expected to diffuse more and more.In this paper, technical and economic studies for the use of Micro CHP in the different climate zones of Iran are executed. These zones are categorized in to five; Tehran, Rasht, Bandar Abbas, Ardebil and Yazd, based on weather conditions. Later on using an economic model, both annual energy savings and percentage of system profitability in each zone are calculated as well as reduction in annual emissions. It should be mentioned that, for economic calculations, gas and electricity price are determined using a sensitivity analysis. This analysis indicated that profitability of Micro CHP systems are sensitive to energy prices, as well as hours needed for heating room in each climate zones.The analysis results show that Ardebil with 38 million RLS (with electricity buyback) annual energy saving is recognized as the best option for installing Micro CHP. On the other hand, Bandar Abbas with 2.5 million RLS annual energy saving is not suitable.     

Economical analysis and relation between energy inputs and yield of greenhouse cucumber production in Iran

This paper studies the energy balance between the input and the output per unit area for greenhouse cucumber production. For this purpose, the data on 43 cucumber production greenhouses in the Tehran province, Iran, were collected and analyzed. The results indicated that a total energy input of 148836.76 MJ ha⁻¹ was consumed for cucumber production. Diesel fuel (with 41.94%) and chemical fertilizers (with 19.69%) were amongst the highest energy inputs for cucumber production. The energy productivity was estimated as 0.80 kg MJ⁻¹. The ratio of energy output to energy input was approximately 0.64. Results indicate 10.93% and 89.07% of total energy input was in renewable and non-renewable forms, respectively. The regression results revealed that the contribution of energy inputs on crop yield (except for fertilizers and seeds energies) was significant. The human labour energy had the highest impact (0.35) among the other inputs in greenhouse cucumber production. Econometric analysis indicated that the total cost of production for one hectare of cucumber production was around 33425.70 $. Accordingly, the benefit–cost ratio was estimated as 2.58.     

An investigation on energy consumption and sensitivity analysis of soybean production farms

The aims of this study were to determine the energy consumption and evaluation of inputs sensitivity for soybean production in Kordkuy county of Iran. The data used in this study were obtained from 32 farmers using a face-to-face questionnaire base of random sampling method. The sensitivity of energy inputs was estimated using the marginal physical productivity (MPP) method and partial regression coefficients on soybean yield. The results indicated that the total input and output energy use was to be 18,026.50 and 71,228.86 MJ ha⁻¹ respectively. With 66.67%, the diesel fuel was the highest within the energy equivalents and followed by chemical fertilizers and water for irrigation with 14.32% and 6.18% respectively. The input-output ratio was found as 4.62 (used efficiency). The share of direct, indirect, renewable and non-renewable was 74%, 26%, 14% and 86% respectively. The econometric model estimation emphasized that the seed was significantly positive on yield. The sensitivity analysis indicated the MPP value of 2.42 for seed, indicates that with an additional use of 1 MJ of seed energy would lead to an increase in yield by 2.42. The impact of direct, indirect and non-renewable energies on yield was significant.     

Energy inputs and crop yield relationship in potato production in Hamadan province of Iran

The aim of this study was to determine energy consumption and the relationship between energy input and yield for potato production in Kaboud Rahang region of Hamadan state. The data used in this study are collected by questionnaire. The results revealed that nitrogen fertilizer (39%), diesel (21%), seed (14.9%), water (7.5%) and manure (6.4%) consumed the bulk of energy. In the surveyed farms, average yield and energy consumption were calculated as around 28613.7 kg/ha, 92296.3 MJ/ha, respectively. The results also showed that energy ratio, specific energy and energy productivity were 1.1, 3.2 MJ/kg and 0.3 kg/MJ, respectively. An econometric model was developed to estimate the impact of energy inputs on yield by using parametric methods. For this purpose, potato yield, an endogenous variable was assumed to be a function of energy inputs: fertilizer manure, chemical, machinery, human, water for irrigation, diesel and seed. The empirical results indicated that variables: fertilizer, chemical, seed and human were found statistically significant and contributed to yield. Among statistically significant exogenous variables, seed, water for irrigation, chemical, human and fertilizer were ranked in terms of elasticities.     

Energy consumption and economic activities in Iran

The causal relationship between overall GDP, industrial and agricultural value added and consumption of different kinds of energy are investigated using vector error correction model for the case of Iran within 1967–2003. A long-run unidirectional relationship from GDP to total energy and bidirectional relationship between GDP and gas as well as GDP and petroleum products consumption for the whole economy was discovered. Causality is running from value added to total energy, electricity, gas and petroleum products consumption and from gas consumption to value added in industrial sector. The long-run bidirectional relations hold between value added and total energy, electricity and petroleum products consumption in the agricultural sector. The short-run causality runs from GDP to total energy and petroleum products consumption, and also industrial value added to total energy and petroleum products consumption in this sector.     

Wood pellets production costs and energy consumption under different framework conditions in Northeast Argentina

The development of cleaner and renewable energy sources are needed in order to reduce dependency and global warming. Wood pellets are a clean renewable fuel and has been considered as one of the substitutes for fossil fuels. In Argentina, large quantities of sawmill residues are still unused and wood pellets production could be seen as both, as an environmental solution and an extra economical benefit. The general aim of this study was to determine the wood pellets production costs and energy consumption under different framework conditions in northeast Argentina. The specific costs of wood pellets for the different scenarios showed relative lower costs comparing to the ones reported in other studies, ranging from 35 to 47 €/Mg_pellets. Raw material costs represented the main cost factor in the calculation of the total pellets production costs. A lower specific production cost was observed when 50% of the raw material input was wood shavings. The specific electricity consumption per metric ton of pellet was lower in scenarios with higher production rate. Lower heat energy consumption was observed in scenarios that have a mixed raw material input. The most promising framework condition for Northeast Argentina, in terms of costs effectiveness and energy consumption could be acquired with production rates of 6 Mg/h with sawdust and wood shavings as raw material. However, simultaneous increment of the electricity by 50% and raw material price by 100% may increase the specific costs up to 50%.     

Energy use efficiency in greenhouse tomato production in Iran

Efficient use of energy in agriculture is one of the conditions for sustainable production. In the present study energy use pattern for tomato production in Iran was investigated and a non-parametric data envelopment analysis (DEA) technique was applied to analyze the technical and scale efficiencies of farmers with respect to energy use for crop production. The energy use pattern indicated that diesel, electricity and chemical fertilizers are the major energy consuming inputs for tomato production in the region. Moreover, the results of DEA application revealed that of the average pure technical, technical and scale efficiencies of farmers were 0.94, 0.82 and 0.86, respectively. Also the results revealed that by adopting the recommendations based on the present study, on an average, about 25.15% of the total input energy could be saved without reducing the tomato yield.     

Energy and economic assessment of soda and organosolv biorefinery processes

Lignocellulosic biomass, particularly agricultural and forestry residues, is becoming a potential renewable energy and products source. Lignocellulosic biomass processing technologies include a primary separation of its main constituents, cellulose, hemicelluloses and lignin, as well as further treatment and processing to obtain different platform chemicals to design consistently structured compounds as chemical building blocks. The economic competitiveness of the obtained products is highly dependent on the separation and purification technologies used and the process energetic efficiency. For this proposal, process simulation tools are very useful to design a competitive and effective biorefinery scheme. In the present work, the energetic and economical efficiencies of two biorefinery processes, soda and organosolv-ethanol systems, were analyzed using the simulation software Aspen Plus^®. The process design consisted of several units (reaction, solid fraction washing, products recovery and liquid fraction processing). Mass and energy balances were established and both systems were compared in terms of yield, solvents/reactants recovery and energy consumption. Aspen HX-Net software was used to analyze the process heat exchange network in order to improve energy consumptions. The development of rigorous simulations allowed to determine the economical feasibility of both biorefinery schemes, and to establish the most appropriate operation conditions for both processes.     

Energy and cost analysis for greenhouse and open-field grape production

The objective of this study was to examine the energy use patterns and cost of production in greenhouse and open-field grape production. Data used in the study were obtained from the experiment conducted at the Akdeniz university research field. In the study, energy values were calculated by multiplying the amount of inputs and outputs by the related energy conversion factors. The results indicated that total input energy use in greenhouse and open-field production was found to be 24513.0 and 23640.9 MJ/ha, respectively. However, the output energy of greenhouse grapes (73396.0 MJ/ha) was lower than open-field grapes (120596 MJ/ha). The output–input ratio for greenhouse and open-field grape production was found to be 2.99 and 5.10, respectively. The economic analysis revealed that production costs for greenhouse grapes were higher than open-field grapes but greenhouse grapes were more profitable than open-field due to premium prices for greenhouse grapes.     

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.     

The relation between Chinese economic development and energy consumption in the different periods

Since the 1980s, Chinese economy grew rapidly. With the rapid economic growth, Chinese energy consumption sharply increased. The relation between Chinese energy consumption and economic growth is focused on, and many researchers have studied this issue by applying the methods such as granger causality test. However, the results just reveal the relation in a very long period. In this paper, the history of Chinese economy is divided into four periods. And the relation between Chinese energy consumption and economic growth is examined by applying grey incidence analysis, which is one of the most important methods of grey system theory which can be applied to solve the problems with small samples. The results show that the relations in different periods are not the same. The degree of grey incidences between total energy consumption and values added of secondary industry is larger, and the degree of grey incidences between GDP and consumption of coal is larger too. And the policy implications of these results are explained.     

Energy consumption and economic growth revisited in African countries

The aim of this paper is to provide new empirical evidence on the relationship between energy consumption and economic growth for 21 African countries over the period from 1970 to 2006, using recently developed panel cointegration and causality tests. The countries are divided into two groups: net energy importers and net energy exporters. It is found that there exists a long-run equilibrium relationship between energy consumption, real GDP, prices, labor and capital for each group of countries as well as for the whole set of countries. This result is robust to possible cross-country dependence and still holds when allowing for multiple endogenous structural breaks, which can differ among countries. Furthermore, we find that decreasing energy consumption decreases growth and vice versa, and that increasing energy consumption increases growth, and vice versa, and that this applies for both energy exporters and importers. Finally, there is a marked difference in the cointegration relationship when country groups are considered.     

Energy efficiency, carbon emissions and economic development in Venezuela

Venezuela's vast natural resource base has largely shaped the nation's economic and energy-use patterns. Major opportunities exist for improving the efficiency of energy use in Venezuela and, consequently, restraining the growth of energy-related carbon emissions. This paper presents a detailed report of one potential development path for Venezuela and estimates the ensuing levels of energy demand and CO₂ emissions associated with pursuing this path through the year 2025. The results indicate that by adopting a development strategy that incorporates structural changes in the economy, fuel-switching measures and improved end-use efficiencies, Venezuela can introduce energy efficiency and carbon restraints as part of its economic development process.