Interrelationships between renewable energy and agricultural economics: An overview

Energy Strategy Reviews 22 (2018) 396–409

Contents lists available at ScienceDirect

Energy Strategy Reviews journal homepage: www.elsevier.com/locate/esr

Review

Interrelationships between renewable energy and agricultural economics: An overview☆

T

Vítor João Pereira Domingues Martinho Agricultural School, Polytechnic Institute of Viseu, 3500, Viseu, Portugal

A R T I C LE I N FO

A B S T R A C T

Keywords: Farming sector Scientific works Bibliometric networks Qualitative analysis ReviewJEL classification: O13 Q01

The relationship between renewable energy and agricultural economics is an interesting topic. In fact, the agricultural sector may be a source for renewable energies, such as biofuel or biomass, but can also provide an important contribution toward the mitigation of environmental impacts from energy use, by consuming sustainable energies. In this framework, the aim of the study presented here, is to explore the interrelationships among renewable energy and agricultural economics over the last decades, through a literature review, identifying, as a base for the future, strengths, weaknesses, opportunities and threats. For data, the 91 studies available in the online platform Web of Science (main database) were considered for the two topics combined together: renewable energy and agricultural economics. These studies were first grouped by sets of terms networked through the VOSviewer software tool and subsequently further explored with the Atlas.ti software. Finally an overview over these studies was formed with subtopics. At the end of this study there will be an analysis to compare larger databases from the Web of Science and from the Scopus. As the main conclusion, it is worth stressing that the contribution of the farming sector to sustainable development, namely in terms of energy use, could be better explored by the several stakeholders. Energy and agricultural policies, the several relevant institutions and the participation of several agents, namely farmers, may improve the efficiency and profitability of the whole process. Both marginal and abandoned land could play an interesting role in the contribution of the agroforestry sector toward the supply of renewable energy.

1. Introduction The environmental impacts from social and economic activities are real these days and will be one of the greatest concerns for society, having several direct and indirect implications upon human life. In this context, the big challenge will be sustainability and sustainable development with balanced relationships between environmental and socioeconomic dimensions. One important question here is energy, not only because of the environmental impacts from energy use of polluting sources (fossil fuels, for example), but, also, because of the future availability of these sources, considering that they are not inexhaustible. In fact, considering the current global levels of energy consumption for several economic and social activities, it is not possible to imagine our life without electricity, for example. The investments which are being made by several countries in renewable energies provide great hope towards dealing with these challenges [1]. The agricultural sector may play a crucial role here, as a source of renewable energies such as, for example, biofuel and biomass that can

☆

provide alternative sources of income for farmers. However, it is worth highlighting the problems caused in some cases by biofuel production, due to the competition with other crops for land space. On the other hand, we can also stress the positive indirect effects from biomass production, namely, for example, in the context of forest fire prevention [2]. In this framework, the main objective of this study is to make a literature review covering the scientific work available in the [3] for the two topics: renewable energy and agricultural economics. With the search performed using this platform 91 studies which were first grouped by sets of terms through the software tool VOSviewer [4] were found. To further explore this set of studies, an analysis with the Atlas.ti [5] was carried out, namely to characterize the distribution of these studies over the years of the last decades and across several scientific documents. In the penultimate section there will be an analysis, to compare, larger databases from the Web of Science and from the Scopus. Finally, an overview of these studies was done, namely to identify the strengths, weaknesses, opportunities and threats in the several

I would like to thank the anonymous reviewers and all those who have contributed, in some way, to this work. E-mail address: [email protected].

https://doi.org/10.1016/j.esr.2018.11.002 Received 14 July 2018; Received in revised form 5 November 2018; Accepted 9 November 2018 2211-467X/ © 2018 Elsevier Ltd. All rights reserved.

Energy Strategy Reviews 22 (2018) 396–409

V.J.P.D. Martinho

Fig. 1. Co-occurrence network from studies related with the two topics: renewable energy and agricultural economics.

links. On the other hand, the distance between the items presents their relatedness (the relatedness increases with the proximity of the items). Another question is about the specificity of the concept cluster for the VOSviewer approaches. For this software, a cluster is a group of items represented in a map and each cluster is indicated by a colour. These clusters are created in a network visualization considering the number and the strength of the links between items. It is worth stressing that the maps presented in this study were created with the VOSviewer software and developed based on the association strength methodology (by default), where the strength of the links between items are considered for normalisation. It was not considered nor fractionalization neither LinLog/modularity approach [6]. The Atlas.ti allows other kinds of analysis and with this software it was possible to export information from the several scientific papers considered by year and by scientific periodical. In turn, it was possible, also, to export information with the number of terms per study. With this information clusters were again created, to go further (taking into account the results obtained with the VOSviewer), with another methodology. In this case, with the number of terms per study, through factor analysis first and after cluster analysis, the new clusters were obtained. In fact, the great problem with cluster analysis (creating groups of elements considering a set of variables) is the collinearity between the several variables. Due to this, in general, initially a small number of factors (indexes) are created from the set of variables considered through factor analysis. In general, these indexes created

interrelationships between renewable energy and agricultural economics. This analysis may provide an interesting basis for the several stakeholders related with the energy and farming sectors, namely for policymakers, but, also, for other producers, consumers and other socioeconomic agents. 2. Methodology explanation In this section some explanation regarding the methodological approaches considered in this study is presented, namely those behind the VOSviewer and the Atlas.ti software. In fact, these programs, sometimes, consider specific concepts that are important to analyse deeper. The VOSviewer is a software application used to develop maps based on network information and for visualizing and analysing these maps. Often, in the network analysis, concepts such as nodes (for the items), edges (for the links) and edge weight (for the strength of a link) are used, however these are not words considered by the VOSviewer. The maps created by this software include items (terms, publications, or authors) and between the items there are links (the strength of each link is indicated by a positive value). In this context, for example, co-occurrences are links among terms and the strength of the links, in these cases (co-occurrences), shows the number of publications in which the terms appear together. In the network map, the VOSviewer represents each item via a label and a circle (by default), their size is dependent upon the item weight and the lines between the items are relative to the 397

Energy Strategy Reviews 22 (2018) 396–409

V.J.P.D. Martinho

occurrence network is present for words such as, for example (Fig. 2): agricultural residue; article; availability; biodiesel; bioethanol; biofuel; biogas; challenge; China; context; ethanol; ethanol production; factor; government; greenhouse gas emission; industry; lack; need; process economic; promotion; review; state; sugar; technology; USA; world. The literature review performed in other sections of this study will shed more light on these words, however, they seem to be related with biofuel production around the world, stressing the cases of China and the USA. For the second group of terms were found words such as (Fig. 3): agricultural land; agricultural production; carbon dioxide emission; consume; efficiency; energy sector; feed; fertilizer; food; form; heat; implementation; India; natural gas; possibility; problem; producer; renewable resource; soil; solar energy; sustainability; time; water. Again, these words need a deeper analysis across the respective scientific studies, however, they seem to be related to the impacts of agro food production. In the third group it is possible to find co-occurrences such as (Fig. 4): case; coal; corn; corn stover; data; economics; effect; energy crop; energy production; farmer; feedstock; negative impact; Poland; price; production cost; research; switchgrass; ton; type. In this group of terms questions arise relating to incomes, prices and costs in the interrelationships between renewable energy and agricultural economics. Finally, are the following co-occurrences for the fourth group

through factor analysis are uncorrelated, thus solving the problems of collinearity [7,8]. With these factors (indexes) a cluster analysis was performed which obtained the clusters shown in the word clouds presented in section 5. In the word clouds the dimension of the word is relative to the number of times the term appeared [9]. It is worth mentioning that the factor and cluster analyses were performed by the Stata software and that the clusters obtained were then exploited by the Altas.ti. These clusters obtained with these methodologies (joining together the Atlas.ti and the Stata) allow for deeper analysis, because it is possible to identify the studies inside each cluster. However, this is related with the kind of outputs produced by each approach. In any case, the results obtained before with the VOSviewer provided for an important basis. 3. Clustering scientific studies related to renewable energy and agricultural economics Considering the 91 scientific studies found on the Web of Science platform, four groups of terms, presented in Fig. 1 were created using the VOSviewer software. For this a map based on text data (term cooccurrence map) was created, considering the title and the abstract as fields from which terms were extracted and using 5 as the minimum number of occurrences for an item. The first group of terms is related to studies where the co-

Fig. 2. Co-occurrence network for the terms related with the first group. 398

Energy Strategy Reviews 22 (2018) 396–409

V.J.P.D. Martinho

Fig. 3. Co-occurrence network for the terms related with the second group.

From the 91 studies obtained from the Web of Science, it was possible to distribute, with the Atlas.ti software, the 85 studies quantified in Table 2. This distribution reveals that the scientific periodicals with the most studies published (6 studies each one) are the following journals: Biomass and Bioenergy; Journal of Forest Economics; Renewable and Sustainable Energy Reviews. The number of studies published in journals such as Biomass and Bioenergy and the Journal of Forest Economics show the importance of the agricultural sector for the production of renewable energies and its contribution towards forestry and sustainability.

(Fig. 5): application; case study; climate; climate change; conversion; decision; economic viability; forest; ghg; investment; land; market; model; net present value; scenario. This set stresses aspects related with climate change, the relationships between forests, investments and the markets, as the most important co-occurrence network. On the other hand, economic viability is also highlighted, here.

4. Distribution of scientific studies over the years of the last decades and across several scientific documents Considering the software Atlas.ti the 91 scientific studies, related with renewable energy and agricultural economics, were analysed deeper and were quantified by year (Table 1) and by scientific document (Table 2). Table 1 shows that the majority of these studies were published after 2010, where the years 2011 and 2017 had the highest record, with, respectively, 11 and 12 studies. Relative to the year 2011, maybe the financial crisis of 2008 had its influence here given the increase in interest concerning these topics. In fact, the financial and economic crisis brought about the driving force for questions such as the roles of renewable energies and the agricultural sector to deal with the new challenges. On the other hand, recent concerns about climate change and the global warming, may explain the scientific interest for these issues in 2017.

5. Identifying the scientific studies behind the clusters obtained With the Atlas.ti software it was possible to obtain a file with the number of times that the terms identified in section 3, for the four groups, appear in each one of the 91 studies analysed. With this file and through factor analysis [7,8] uncorrelated factors were obtained. The next step was to consider these uncorrelated factors to group, through cluster analysis, the 91 scientific studies into four clusters. Table 3 presents the summary statistics for the four clusters obtained. Clusters 1 and 4 are those with more scientific studies and cluster 3 is that with fewer. Table 4 presents the distribution of the 91 studies by the four clusters found (each study is presented by the first 399

Energy Strategy Reviews 22 (2018) 396–409

V.J.P.D. Martinho

Fig. 4. Co-occurrence network for the terms related with the third group.

change between countries or regions, or even over time [12]. In any case, for Taiwan there were also found positive impacts from bioenergy production on the farmers’ income, rice supply and overall welfare [13]. However, in some circumstances the production of renewable energies may compete with the traditional agricultural productions, namely for land and other scarce resources [14,15] and the net balance between the environment and biofuel production is not necessarily positive [16]. In other cases, namely in zones where agricultural land was abandoned, the use of this area for the production of renewable sources of energy may be an option [17,18]. The cellulosic biorefineries may be another important source of alternative and renewable energies, namely to deal with the new challenges related with climate change and global warming [19]. The agricultural sector may contribute actively and positively to strategies that aim to reduc impacts on greenhouse gas emissions, namely through recycling and the conversion of farming residue and waste [20–26] to produce biogas or biodiesel. On the other hand, the modernization of agricultural machinery and equipment, namely considering those that use renewable energies as power sources [27], need, in some cases, adjusted programs, but may be another contribution from the sector for environmental sustainability [28]. Of course, biotechnology and nanotechnology may also bring contributions from the farming sector toward sustainable development [29]. In fact, the agroforestry sector may contribute to the production of renewable energies [30–35], but it can, also, use the respective outputs

author and by the respective title). Figs. 6–9 show that there are some correspondences between the terms found with those obtained with Figs. 1–5 in section 3, despite the different methodologies used by the two softwares considered in both cases (VOSviewer and Atlas.ti, respectively). In fact, the VOSviewer is useful to identify groups of terms, but it only considers the items presented in the title and abstract. In turn, the Atlas.ti considers the terms present in the whole document (however, it is worth stating that for some documents it was only possible to obtain the title and abstract). Considering previous findings, namely those presented in Table 4 and in Figs. 1–9, the literature review in the following section will be made for the following subtopics: agriculture and bioenergy; agriculture, energy and sustainability; energy and farming profitability; agroforestry and climate change. 6. Insights from the scientific documents related with the topics: renewable energy and agricultural economics 6.1. Agriculture and bioenergy Biofuel is an interesting alternative source of energy and with adjusted policies may even benefit the agricultural sector, the environment and welfare [10], namely in countries such as the US. These issues have been focused on and explored by several investigations and studies [11]. Of course, these interrelationships depend on several factors that 400

Energy Strategy Reviews 22 (2018) 396–409

V.J.P.D. Martinho

Fig. 5. Co-occurrence network for the terms related with the fourth group.

to incorporate into their productive processes, in an integrated perspective [36–40]. Policy design should take into account the relationships between farming activities and energy frameworks and play an important role in order to find balanced interrelationships between these two dimensions [41,42].

Table 1 Distribution of the scientific studies by year. Year

Number of works

1991 1993 1994 1996 2001 2002 2003 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017

1 1 1 2 2 1 3 2 2 1 4 4 8 11 8 7 9 8 4 12

6.2. Agriculture, energy and sustainability For a sustainable development it is crucial to reduce the utilization of natural resources and mitigate the impacts from pollution. Namely, the consequences from greenhouse gas emissions which renewable sources of energy may contribute to mitigate [43,44]. To find a balanced relationship between the availability of resources in the ecosystem and human impact is a big challenge [45]. However, these balances are in permanent change and the future will bring new variables to deal with in an already complex framework [46]. Government policies (subsidies, for example) are crucial to promote sustainable interlinkages between the agricultural sector and renewable energies [47,48], namely because of the difficulties found in collecting agroforestry residues and biomass [49]. The institutional policies play a fundamental role, specifically in developing countries, where the difficulties in managing the available resources are greater [50]. The collection, transportation and storage of the residues and biomass are 401

Energy Strategy Reviews 22 (2018) 396–409

V.J.P.D. Martinho

Table 2 Distribution of the scientific studies by scientific document.

Table 3 Summary statistics for the clusters obtained.

Scientific periodical

Number of works

International Conference on Environmental Science and Information Application Technology First International Conference on Agro-Geoinformatics (agroGeoinformatics) Agrarian Perspectives Agrekon Agricultural Economics-Zemedelska Ekonomika Agroecology and Sustainable Food Systems Agroforestry Systems Agronomy for Sustainable Development Aims Environmental Science American Journal of Agricultural Economics Annual Review of Energy and the Environment Applied Economic Perspectives and Policy Applied Energy BioEnergy Research Biofuels, Bioproducts and Biorefining Biomass and Bioenergy Bioresource Technology Biotechnology for Biofuels ChemSusChem Communications in Nonlinear Science and Numerical Simulation Ecological Engineering Ecology, Economics, Education and Legislation Economic Science for Rural Development: Rural Business and Finance Energy Energy Research & Social Science Energy Sources Energy Sources, Part B: Economics, Planning, and Policy Energy, Sustainability and Society Environmental Research Letters Environmental Science & Technology GCB Bioenergy In Vitro Cellular & Developmental Biology - Plant International Journal of Phytoremediation International Journal of Renewable Energy DevelopmentIjred Journal of Agricultural and Environmental Ethics Journal of Agricultural and Resource Economics Journal of Cleaner Production Journal of Energy Engineering Journal of Environmental Management Journal of Forest Economics Journal of Sustainable Agriculture Journal of the Science of Food and Agriculture Mitigation and Adaptation Strategies for Global Change Proceedings of the 8th International Conference on Environmental Science and Technology Proceedings of the Sixth Ieee Global Humanitarian Technology Conference Ghtc 2016 Renewable and Sustainable Energy Reviews Renewable Energy Research for Rural Development 2012 Resources, Conservation and Recycling Rocznik Ochrona Srodowiska Rural Development 2013: Proceedings Science Smart and Sustainable Planning for Cities and Regions Soy-Based Chemicals and Materials Sugar Industry-Zuckerindustrie The International Journal of Life Cycle Assessment Water Science and Technology Zuckerindustrie

1 1 1 1 1 1 1 1 1 1 1 2 2 3 2 6 2 1 1 1

Cluster analysis

Freq.

Percent

Cum.

1 2 3 4 Total

33 21 3 34 91

36.26 23.08 3.30 37.36 100

36.26 59.34 62.64 100

interrelations among the farming sector and the supply and demand for energy. However, these solutions depend on the characteristics of the countries/regions and the farms, where the size of the farm may be determinant in the analysis of benefit-cost [53,54]. The same happens with other renewable resources of energy, where the current and structural profitability depends on several variables [55], such as the technology of production, the efficiency of the processes, the kind of residues and biomass considered and the kind of crops used [56]. The alternative and renewable energies from agricultural sources are not exempt from having negative implications upon sustainable development, namely because the need for irrigation of some crops such as corn, bringing about concerns for water use and availability [57], as well as for soil erosion [59]. The availability of freshwater is already a problem in many global regions [60], that may become worse around the world due to climate change. On the other hand, the implications from renewable energy production upon the reduction of food production cannot be neglected in some circumstances [61,62]. However, the net balance from the use of bioenergy seems to be positive, considering the economic and environmental scopes. Currently, bioenergy is often considered as a resource to be used in many fields of society and across economic activities [63]. In the context of bioenergy, Brazil and USA may have interesting contributions in the fields of bioethanol, India and China with biogas and the European Union with biodiesel [50,64].

1 1 1 3 1 2 2 1 1 1 2 1 1 1

6.3. Energy and farming profitability

1 1 1 1 1 6 1 1 1 1

The cost of production and various prices involved in the energy markets influence profitability and decision making within the sector of renewable energies from agroforestry activities. In fact, sometimes the prices payed for feedstocks from the farming sector are not attractive, facing the several costs associated (production, transportation and storage). In other cases, however, the prices involved in the production of biomass are not competitive comparative to the production of food. Finally, the input prices here also have an impact, namely those related with operational factors of production [65]. In certain areas, namely those contaminated with metals, or without the right conditions to be competitive with traditional activities (to produce, for example, food), the production of energy crops may be an interesting way to increase the income of the farmers and the profitability of farms. The level of profitability depends on the capacity of farmers to appreciate or add value, namely through the conversion of these crops into energy [66]. Amongst renewable energy sources, bioenergy was the most important in Poland around 2006 [67]. In the Polish context the willow competes with cereals in the field of energy crops production. However, the profitability of each one of these crops depends on the various prices implemented, as referred to before.

1 6 1 1 2 1 1 1 1 1 1 1 1 1

6.4. Agroforestry and climate change determinant factors in the production of bioenergy that may be mitigated by the participation of farmers [51]. For an effective implementation of any public strategy, the organizations and institutions may have important contributions, such as the energy cooperatives in Germany [52]. Biogas plants may be a solution, in many cases, for sustainable

Climate change and concerns about the environment [68] and greenhouse gas emissions is on the agenda for several governments around the world and for researchers [69–71]. The agroforestry sector may play an important role for climate change mitigation [72–74], namely through carbon sequestration [75] and biomass supply, for 402

Energy Strategy Reviews 22 (2018) 396–409

V.J.P.D. Martinho

Table 4 Cluster analysis for the 91 scientific studies related with the topics renewable energy and agricultural economics. Scientific work name

Clusters

Moschini (2017) - The Renewable Fuel Standard in Competitive Equilibrium: Market and Welfare Effects Sadula (2017) - Process Intensification for Cellulosic Biorefineries Dimoudi (2015) - Transformation of a Small-Livestock, Rural Community into a Green, Nearly-Zero CO2-Emissions Settlement Spielberg (2016) - Small-Scale Solar Pumping Systems in India Analysis of Three Implementation Models Alemayehu (2015) - Status and Benefits of Renewable Energy Technologies in the Rural Areas of Ethiopia: A Case Study on Improved Cooking Stoves and Biogas Technologies Niculae (2015) - Study Regarding Waste Management in Romania Chang (2015) - Economic effects of the biochar application on rice supply in Taiwan Costanza (2015) - Linking state-and-transition simulation and timber supply models for forest biomass production scenarios Koch (2014) - Sugar beet syrups in lactic acid fermentation - Part II Saving nutrients by lactic acid fermentation with sugar beet thick juice and raw juice Mumm (2014) - Land usage attributed to corn ethanol production in the United States: sensitivity to technological advances in corn grain yield, ethanol conversion, and co-product utilization Roberts (2014) - Small Scale Prototype Biomass Drying System for Co-Combustion with Coal Mishra (2014) - Cost and Benefit Analysis of Bio Energy Alternatives in India Al Loman (2014) - Arabitol Production from Glycerol by Fermentation Clark (2013) - Growing a sustainable biofuels industry: economics, environmental considerations, and the role of the Conservation Reserve Program Zeverte-Rivza (2013) - Biogas Production in Latvia: the Current State and Future Forecasts Lenerts (2012) - Role of Land Resources in the Development of the Market of Renewable Energy Sources of Agricultural Origin in Latvia Liu (2012)- Bioenergy production potential on marginal land in Canada Blumenstein (2012) - On the economics of bio-energy recovery from semi-natural grasslands Makovskis (2012) - Economic Calculation of Short Rotation Willow Plantations in Latvia Tronstad (2011) - Unpleasant Lessons from the Settlement of the West: Implications for the WAEA and Other Professional Associations Gloy (2011) - The Potential Supply of Carbon Dioxide Offsets from the Anaerobic Digestion of Dairy Waste in the United States Kowalski (2011) - Modeling of Biomass Market in Malopolska Region Including Legal, Market and Environmental Aspects de Gorter (2010) - The Social Costs and Benefits of Biofuels: The Intersection of Environmental, Energy and Agricultural Policy Vilhelm (2010) - The energy balance of agricultural production and its political impacts Gallaspy (2010) - Application of Regional Bio-Refining to Increase the Sustainability and Energy Self-Sufficiency of Rural and Agricultural Communities Lanzerstorfer (2008) - Decentralized integrated biogas and bioethanol production Wilson (2008) - Thermal Characteristics of Sugar Cane Bagasse with Storage Liguras (2003) - A novel, highly efficient and environmentally friendly process for combined heat and power production from biomass Keller (2003) - Greenhouse gas production in wastewater treatment: process selection is the major factor Dickson (1996) - Meeting greenhouse targets in Australia: Implications for coal use Hughes Turnbull (1994) - Developing an integrated approach to biomass energy systems in the united states Huston (1993) - Biological Diversity, Soils, and Economics U-tapao (2015) - Stochastic, Multiobjective, Mixed-Integer Optimization Model for Wastewater-Derived Energy Hanes (2017) - Synergies and trade-offs in renewable energy landscapes: Balancing energy production with economics and ecosystem services Abbas (2017) - Economic analysis of biogas adoption technology by rural farmers: The case of Faisalabad district in Pakistan Liu (2017) - Potential water requirements of increased ethanol fuel in the USA Regan (2017) - Climate change and the economics of biomass energy feedstocks in semi-arid agricultural landscapes: A spatially explicit real options analysis Singh (2017) - Management of the agricultural biomass on decentralized basis for producing sustainable power in India Reif (2015) - Solar-thermal powered desalination: Its significant challenges and potential Wang (2016) - Bio-jet fuel conversion technologies Yildiz (2015) - Renewable energy cooperatives as gatekeepers or facilitators? Recent developments in Germany and a multidisciplinary research agenda Coulman (2013) - Developments in crops and management systems to improve lignocellulosic feedstock production Clancy (2012) - A stochastic analysis of the decision to produce biomass crops in Ireland Sparks (2011) - Global biofuel policies: A review Leboreiro (2011) - Biomass transportation model and optimum plant size for the production of ethanol Chel (2011) - Renewable energy for sustainable agriculture Bryan (2010) - Biofuels agriculture: landscape-scale trade-offs between fuel, economics, carbon, energy, food, and fiber McHenry (2010) - Carbon-based stock feed additives: a research methodology that explores ecologically delivered C biosequestration, alongside live weights, feed use efficiency, soil nutrient retention, and perennial fodder plantations Gui (2008) - Feasibility of edible oil vs. non-edible oil vs. waste edible oil as biodiesel feedstock Amigun (2008) - Commercialisation of biofuel industry in Africa: A review Ugarte (2007) - Is the expansion of biofuels at odds with the food security of developing countries? Dornburg (2006) - Economics and GHG emission reduction of a PLA bio-refinery system—Combining bottom-up analysis with price elasticity effects Gnansounou (2005) - Refining sweet sorghum to ethanol and sugar: economic trade-offs in the context of North China Graham (2003) - Potential for climate change mitigation through afforestation: an economic analysis of fossil fuel substitution and carbon sequestration benefits Krasuska (2012) - Economics of energy crops in Poland today and in the future Thewys (2010) - Economic Viability of Phytoremediation of a Cadmium Contaminated Agricultural Area Using Energy Maize. Part II: Economics of Anaerobic Digestion of Metal Contaminated Maize in Belgium Ericsson (2006) - An agro-economic analysis of willow cultivation in Poland Xian (2017) - Do nonrenewable-energy prices affect renewable-energy volatility? The case of wood pellets Song (2017) - Integrated Economic and Environmental Assessment of Cellulosic Biofuel Production in an Agricultural Watershed Tarr (2017) - Projected gains and losses of wildlife habitat from bioenergy-induced landscape change Jin (2017) - Economic assessment of biomass gasification and pyrolysis: A review Cheng (2017) - Waste-to-energy policy in China: A national strategy for management of domestic energy reserves Ravi (2016) - Colocation opportunities for large solar infrastructures and agriculture in drylands Dinesh (2016) - The potential of agrivoltaic systems Lantz (2014) - Benefit-cost analysis of hybrid willow crop production on agricultural land in eastern Canada: Assessing opportunities for on-farm and off-farm bioenergy use Geijer (2014) - Safeguarding species richness vs. increasing the use of renewable energy—The effect of stump harvesting on two environmental goals He (2014) - Woody biomass potential for energy feedstock in United States Mu (2013) - Emergy Synthesis of the Agroecosystem in Yan'an Area of China

1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 3 3 3 4 4 4 4 4 4 4 4 4 4 4

(continued on next page) 403

Energy Strategy Reviews 22 (2018) 396–409

V.J.P.D. Martinho

Table 4 (continued) Scientific work name

Clusters

Latta (2013) - A multi-sector intertemporal optimization approach to assess the GHG implications of U.S. forest and agricultural biomass electricity expansion Kallio (2013) - Sequester or substitute—Consequences of increased production of wood based energy on the carbon balance in Finland Moiseyev (2013) - Wood biomass use for energy in Europe under different assumptions of coal, gas and CO2 emission prices and market conditions Mosher (2012) - Agriculture's contribution to the renewable energy sector: Policy and economics – Do they add up? Sorgüven (2012) - Energy utilization, carbon dioxide emission, and exergy loss in flavored yogurt production process Özilgen (2011) - Energy and exergy utilization, and carbon dioxide emission in vegetable oil production Odeh (2011) - Potential Suitability and Viability of Selected Biodiesel Crops in Australian Marginal Agricultural Lands Under Current and Future Climates Hanff (2011) - Are biofuels an efficient technology for generating sustainable development in oil-dependent African nations? A macroeconomic assessment of the opportunities and impacts in Burkina Faso Brechbill (2011) - The Economics of Biomass Collection and Transportation and Its Supply to Indiana Cellulosic and Electric Utility Facilities Magagnotti (2011) - Financial and energy cost of low-impact wood extraction in environmentally sensitive areas Gregg (2010) - Global and regional potential for bioenergy from agricultural and forestry residue biomass Roberts (2010) - Life Cycle Assessment of Biochar Systems: Estimating the Energetic, Economic, and Climate Change Potential Sainz (2009) - Commercial cellulosic ethanol: The role of plant-expressed enzymes Yang (2009) - Exergetic evaluation of corn-ethanol production in China Foley (2009) - Regional normalisation figures for Australia 2005/2006—inventory and characterisation data from a production perspective Chen (2009) - Emergy Depletion and Offset of Fossil Energy Assets in China McLaughlin (2005) - Development of switchgrass (Panicum virgatum) as a bioenergy feedstock in the United States Kaygusuz (2002) - Review of Biomass Energy in Turkey Kaygusuz (2001) - Hydropower and Biomass as Renewable Energy Sources in Turkey Zentner (2001) - In Search of a Sustainable Cropping System for the Semiarid Canadian Prairies Barnes (1996) - RURAL ENERGY IN DEVELOPING COUNTRIES: A Challenge for Economic Development Pimentel (1991) - Ethanol fuels: Energy security, economics, and the environment Corscadden (2014) - Sheep's wool insulation: A sustainable alternative use for a renewable resource?

4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4

Fig. 6. Main words found for cluster 1.

Fig. 8. Main words found for cluster 3.

Fig. 9. Main words found for cluster 4. Fig. 7. Main words found for cluster 2.

biomass and with fewer residues, than with corn stovers, but with higher costs [80]. In turn, in some cases, it would seem to be more profitable to use biomass as a source of renewable energy for the activities carried out within the respective farm [81]. Biomass as a source of energy represents a relatively higher importance in developing and lesser developed countries [82–84]. The demand for wood biomass will promote changes in the way the forest is seen [85] and managed, with positive impacts upon biotic and abiotic damage mitigation, namely with the reduction of the fuel load. However, the consequences on biodiversity and on species conservation cannot be ignored [86,87]. The destination given to biomass and residues from the agroforestry sector depends on the options of conversion of each country and, of

example, for wood-pellets production. However, it is not generally accepted that the use of wood to produce energy, reduces greenhouse gas emissions, namely because reductions in carbon sinks [76]. The same discussions about the renewability of these processes occur for other renewable energies obtained from the agroforestry sector [77,78]. Over the last decade, the United States was an interesting exporter of woodpellets to Europe [79]. The level of biomass production, as well the respective costs, from the agroforestry sector depends on several factors, such as the dimension and location of the farm and the species of the crops considered. For example, perennial grasses, in certain circumstances, produce more

404

Energy Strategy Reviews 22 (2018) 396–409

V.J.P.D. Martinho

Fig. 10. Co-occurrence network for the terms from the studies obtained from all Web of Science databases.

analyse the scientific studies related with these two subjects. For this, 91 studies were considered from the Web of Science (main database) scientific platform. However, considering the quantity of information related with these topics available on the whole database [102] from the Web of Science (information associated with 2242 documents) and from the Scopus (information associated with 501 documents) platform [103], they are presented in this section, to compare with the results obtained in the previous sections, the co-occurrence maps for these two cases (Scopus and all Web of Science databases), using the VOSviewer software. As concluded before, Figs. 10 and 11 confirm that the questions related with alternative and renewable sources of energy, sustainability, land use and economic profitability (costs, income, prices, outputs, inputs) are crucial when addressing the two topics: renewable energy and agricultural economics. In fact, the questions related with the production of renewable energies from agricultural production and residues [104,105], the profitability of the whole system [106–108], the conflicts and questions related with land use [109–111] and, finally, the environmental impact and sustainability of all these options [58]. are interrelated [112–114], when analysing aspects related with renewable sources of energy and

course, the differing impacts on greenhouse gas emissions. However, in any case, the availability of biomass and waste in countries such as China is enormous and its use for the production of renewable energies is an interesting option [88]. In this biomass and waste conversion, gasification seems to be the most attractive, in terms of economic and environmental advantages [89]. In fact, the impacts from renewable energy use and production on, namely, greenhouse gas emissions are interrelated with the options of management of the processes, the technology considered and opportunity costs [90–97], where concepts such as the agrivoltaic could have its place. If the decisions of several economic agents were to have relevant impacts on climate change occurrences [98,99], the same would happen in the reverse direction. In fact, global warming will influence the options that may be chosen by farmers, namely in the choice of adjusted crops [100,101].

7. Results of the whole database from the Web of Science and for Scopus The main objective of this study is to explore the networks between the topics “renewable energy and agricultural economics” and further 405

Energy Strategy Reviews 22 (2018) 396–409

V.J.P.D. Martinho

Fig. 11. Co-occurrence network for the terms from the studies obtained from the Scopus.

production of renewable energies, through biomass, biofuel and biogas and can benefit from these bioenergy productions by selling or incorporating them into the productive processes, with relevant cost reductions. Public and institutional policies play a determinant role here to promote these interrelationships between these two dimensions, as well as the modernization of the productive processes in farms, where new technologies and biotechnologies have their place here. The production of renewable energies from the agricultural sector is not exempt from negative impacts, conflicts, or at least controversial discussion. One of the most raised questions concerns the competition between energy crops and food crops, such as, for example land space. Marginal and abandoned land may be an interesting contribution here. - The relationships between farming activities and energy production and consumption are not always easy and sometimes unbalanced. It is crucial to promote sustainable relationships among these two dimensions and, again, government policies and the participation of the stakeholders can have a determinant contribution. On the other hand, the institutional framework, such as the energy cooperatives, is another piece to the equation that should be taken into account, namely by policymakers. In these aspects related with sustainability,

agricultural performance. Another question is with regards to the design of the policies related with renewable energies that sometimes is not exempt from criticism [115]. In any case, it is crucial to involve the several stakeholders in the whole process of policy design. 8. Conclusions In terms of research approach, this study was aimed at making an overview over the relationships between renewable energy and agricultural economic topics. For this, 91 studies were obtained from the Web of Science platform that were first analysed and clustered with the VOSviewer and Atlas.ti software and subsequently analysed further through literature review. These approaches showed that the 91 works focus, namely, on four issues: agriculture and bioenergy; agriculture, energy and sustainability; energy and farming profitability; agroforestry and climate change. Considering the results obtained before, of highlighting the following main findings: - The agricultural sector may contribute strongly toward the

406

Energy Strategy Reviews 22 (2018) 396–409

V.J.P.D. Martinho

it would be worth stressing the negative impacts from some renewable energy sources in the availability of some other necessary resources such as water. - The profitability of renewable energy from the farming sector depends on several factors, namely those related with the technologies considered, the processes management, the kind of feedstock used and the prices practiced by the several markets related with bioenergy production. The prices practiced for agricultural inputs, for biomass and residues from the sector and for fossil fuel energies can either guarantee or destroy the profitability of the whole process. The several prices appear as one of the most important determinants of the levels of cost and income in bioenergy production. - Finally, the farmers' decisions will influence climate change and global warming, but the reverse is also true. The discussions about the impact of renewable energies from the agroforestry sector on greenhouse gas emissions are, also, not consensual. However, the conversion of agroforestry biomass and residues into biogas seems to be the cleaner solution, comparative to biofuels or wood biomass.

[17]

[18]

[19]

[20] [21]

[22]

[23]

[24]

As final comments, it could be important that the several agricultural stakeholders, namely the policymakers, take into account the findings presented here. In fact, it could be interesting to see the instruments from agricultural policy, namely from the European Union Common Agricultural Policy, address, in a sustainable way, the questions related with the production and use of renewable energies in farms, with benefits for the profitability of the sector. In any case, in these processes it may be important to involve the several stakeholders into the design of adjusted policies.

[25]

[26]

[27]

References [28]

[1] V.J. Martinho, A transversal perspective on global energy production and consumption: an approach based on convergence theory, Energy Environ. (2018) 0958305X18754379 https://doi.org/10.1177/0958305X18754379. [2] P.R. Mourão, V.D. Martinho, The choices of the fire — debating socioeconomic determinants of the fires observed at Portuguese municipalities, For. Policy Econ 43 (2014) 29–40 https://doi.org/10.1016/j.forpol.2014.01.007. [3] Web of Science, Web of science platform, WWW Document https://apps. webofknowledge.com/WOS_GeneralSearch_input.do?product=WOS&search_ mode=GeneralSearch&SID=F3thLlaCM72Vzo9yfmp&preferencesSaved=, (2018) , Accessed date: 30 January 2018. [4] VOSviewer, VOSviewer - visualizing scientific landscapes, [WWW Document]. VOSviewer http://www.vosviewer.com//, (2018) , Accessed date: 30 January 2018. [5] Atlasti, ATLAS.ti: the Qualitative Data Analysis & Research Software, (2018) WWW Document http://atlasti.com/ , Accessed date: 30 January 2018. [6] N.J. van Eck, L. Waltman, VOSviewer manual, WWW Document, 2018. http:// www.vosviewer.com/documentation/Manual_VOSviewer_1.6.8.pdf. [7] Torres-Reyna, O., n.d. Getting Started in Factor Analysis (using Stata 10) (ver. 1.5) [WWW Document]. URL https://www.stata.com/(accessed 1.30.2018). [8] Stata, Stata: data analysis and statistical software, WWW Document https://www. stata.com/, (2018) , Accessed date: 30 January 2018. [9] D.S. Friese, ATLAS.ti 8 windows - user manual, WWW Document, 2018. http:// downloads.atlasti.com/docs/manual/atlasti_v8_manual_en.pdf. [10] G. Moschini, H. Lapan, H. Kim, The renewable fuel standard in competitive equilibrium: market and welfare effects, Am. J. Agric. Econ. 99 (2017) 1117–1142 https://doi.org/10.1093/ajae/aax041. [11] R. Tronstad, Unpleasant lessons from the settlement of the west: implications for the WAEA and other professional associations, J. Agric. Resour. Econ. 36 (2011) 433–447. [12] R.H. Mumm, P.D. Goldsmith, K.D. Rausch, H.H. Stein, Land usage attributed to corn ethanol production in the United States: sensitivity to technological advances in corn grain yield, ethanol conversion, and co-product utilization, Biotechnol. Biofuels 7 (2014) 61 https://doi.org/10.1186/1754-6834-7-61. [13] M.-S. Chang, W. Wang, C.-C. Kung, Economic effects of the biochar application on rice supply in Taiwan, Agric. Econ.-Zemed. Ekon. 61 (2015) 284–295 https://doi. org/10.17221/147/2014-AGRICECON. [14] T. Liu, Z. Ma, S. Kulshreshtha, B. McConkey, T. Huffman, M. Green, J. Liu, Y. Du, J. Shang, Bioenergy production potential on marginal land in Canada, 2012 First International Conference on Agro-geoinformatics (Agro-geoinformatics), Ieee, New York, 2012, pp. 650–655. [15] J.K. Costanza, R.C. Abt, A.J. McKerrow, J.A. Collazo, Linking state-and-transition simulation and timber supply models for forest biomass production scenarios, Aims Environ. Sci. 2 (2015) 180–202 https://doi.org/10.3934/environsci.2015.2. 180. [16] C.M. Clark, Y. Lin, B.G. Bierwagen, L.M. Eaton, M.H. Langholtz, P.E. Morefield,

[29]

[30] [31]

[32] [33] [34]

[35]

[36]

[37] [38] [39]

[40]

[41]

[42]

[43]

407

C.E. Ridley, L. Vimmerstedt, S. Peterson, B.W. Bush, Growing a sustainable biofuels industry: economics, environmental considerations, and the role of the Conservation Reserve Program, Environ. Res. Lett. 8 (2013) 025016 https://doi. org/10.1088/1748-9326/8/2/025016. B. Blumenstein, D. Moeller, On the Economics of Bio-energy Recovery from Seminatural Grasslands, Polish Grassland Soc-Polskie Towarzystwo Lakarskie, Poznan, 2012. K. Makovskis, D. Lazdina, L. Bite, Economic calculation of short rotation willow plantations in Latvia, in: S. Treija, I. Skuja (Eds.), Research for Rural Development 2012, vol. 2, Latvia Univ Agriculture, Jelgava, 2012, pp. 224–229. S. Sadula, A. Athaley, W. Zheng, M. Ierapetritou, B. Saha, Process intensification for cellulosic biorefineries, ChemSusChem 10 (2017) 2566–2572 https://doi.org/ 10.1002/cssc.201700183. C. Lanzerstorfer, A. Jaeger, Decentralized integrated biogas and bioethanol production, Zuckerindustrie 133 (2008) 642–645. B.A. Gloy, The potential supply of carbon dioxide offsets from the anaerobic digestion of dairy waste in the United States, Appl. Econ. Perspect. Policy 33 (2011) 59–78 https://doi.org/10.1093/aepp/ppq029. S. Zeverte-Rivza, Biogas production in Latvia: the current state and future forecasts, in: V. Atkociuniene (Ed.), Rural Development 2013: Proceedings, Vol6, Book 1, Aleksandras Stulginskis University, Akademija, 2013, pp. 472–477. A. Al Loman, L.-K. Ju, Arabitol production from glycerol by fermentation, in: R.P. Brentin (Ed.), Soy-based Chemicals and Materials, Amer Chemical Soc, Washington, 2014, pp. 109–126. Y.A. Alemayehu, Status and benefits of renewable energy technologies in the rural areas of Ethiopia: a case study on improved cooking stoves and biogas technologies, Int. J. Renew. Energy Dev.-Ijred 4 (2015) 103–111 https://doi.org/10. 14710/ijred.4.2.103-111. A. Dimoudi, V. Stathis, C. Pallas, Transformation of a small-livestock, rural community into a green, nearly-zero CO2-emissions settlement, Smart and Sustainable Planning for Cities and Regions, Green Energy and Technology. Presented at the International Conference on Smart and Sustainable Planning for Cities and Regions, Springer, Cham, 2015, pp. 319–334 https://doi.org/10.1007/978-3-31944899-2_19. I. Niculae, C.S. Buzatu, G.M. Costaiche, A. Marin, Study regarding waste management in Romania, Ecology, Economics, Education and Legislation, Iii Stef92 Technology Ltd, Sofia, 2015, pp. 599–606. D.T. Gallaspy, R.E. Sears, Application of Regional Bio-refining to Increase the Sustainability and Energy Self-sufficiency of Rural and Agricultural Communities, Amer Soc Mechanical Engineers, New York, 2010. J.B. Spielberg, A. Gandhi, S.L. Pesek, J.L. Green, V. Pandya, E. Ilten, Small-Scale solar pumping systems in India analysis of three implementation models, Proceedings of the Sixth Ieee Global Humanitarian Technology Conference Ghtc 2016, Ieee, New York, 2016, pp. 33–39. T.J. Koch, J. Venus, Sugar beet syrups in lactic acid fermentation - Part II Saving nutrients by lactic acid fermentation with sugar beet thick juice and raw juice, Sugar Ind.-Zuckerind. 139 (2014) 683–690. M. Huston, Biological diversity, soils, and economics, Science 262 (1993) 1676–1680 https://doi.org/10.1126/science.262.5140.1676. J. Hughes Turnbull, Developing an integrated approach to biomass energy systems in the United States, Biomass Bioenergy, Environmental Aspects of Energy Forest Cultivation 6 (1994) 151–158 https://doi.org/10.1016/0961-9534(94)90095-7. A. Dickson, K. Noble, Z.Y. Peng, J. Dlugosz, R. Stuart, Meeting Greenhouse Targets in Australia: Implications for Coal Use, C S I R O, East Melbourne, 1996. J. Keller, K. Hartley, Greenhouse gas production in wastewater treatment: process selection is the major factor, Water Sci. Technol. 47 (2003) 43–48. Z. Kowalski, L. Lelek, Modeling of biomass market in malopolska region including legal, market and environmental aspects, Rocz. Ochr. Srodowiska 13 (2011) 1429–1440. A. Lenerts, I. Pilvere, Role of land resources in the development of the market of renewable energy sources of agricultural origin in Latvia, in: A. ZvirbuleBerzina (Ed.), Economic Science for Rural Development: Rural Business and Finance: 1. Rural Business Economics and Administration, 2. Finance and Taxes, Latvia Univ Agriculture, Jelgava, 2012, pp. 73–79. D.K. Liguras, X.E. Verykios, A novel, highly efficient and environmentally friendly process for combined heat and power production from biomass, in: T.D. Lekkas (Ed.), Proceedings of the 8th International Conference on Environmental Science and Technology, Vol B, Poster Presentations, Univ Aegean, Athens, 2003, pp. 476–483. L. Wilson, G.R. John, C.F. Mhilu, Thermal Characteristics of Sugar Cane Bagasse with Storage, World Publishing Corporation, Beijing, 2008. T. Mishra, Cost and Benefit Analysis of Bio Energy Alternatives in India, Ieee, New York, 2014. H. Roberts, M. Favrow, J. Coatney, D. Yoe, C. Langness, C. Depcik, Small Scale Prototype Biomass Drying System for Co-combustion with Coal, Amer Soc Mechanical Engineers, New York, 2014. C. U-tapao, S.A. Gabriel, C. Peot, M. Ramirez, Stochastic, multiobjective, mixedinteger optimization model for wastewater-derived energy, J. Energy Eng. 141 (2015) B5014001 https://doi.org/10.1061/(ASCE)EY.1943-7897.0000195. H. de Gorter, D.R. Just, The social costs and benefits of biofuels: the intersection of environmental, energy and agricultural policy, Appl. Econ. Perspect. Policy 32 (2010) 4–32 https://doi.org/10.1093/aepp/ppp010. V. Vilhelm, The energy balance of agricultural production and its political impacts, Agrarian Perspectives vol. 6, Czech University Life Sciences Prague, Prague, 2010, pp. 181–199. P.J. Graham, Potential for climate change mitigation through afforestation: an

Energy Strategy Reviews 22 (2018) 396–409

V.J.P.D. Martinho

[44]

[45]

[46]

[47] [48] [49]

[50]

[51]

[52]

[53]

[54]

[55]

[56]

[57]

[58]

[59]

[60]

[61]

[62]

[63] [64]

[65]

[66]

[67]

[68]

https://doi.org/10.1016/j.resconrec.2014.01.004. [69] J. Foley, P. Lant, Regional normalisation figures for Australia 2005/2006—inventory and characterisation data from a production perspective, Int. J. Life Cycle Assess. 14 (2009) 215–224 https://doi.org/10.1007/s11367-009-0063-y. [70] E. Hanff, M.-H. Dabat, J. Blin, Are biofuels an efficient technology for generating sustainable development in oil-dependent African nations? A macroeconomic assessment of the opportunities and impacts in Burkina Faso, Renew. Sustain. Energy Rev. 15 (2011) 2199–2209 https://doi.org/10.1016/j.rser.2011.01.014. [71] J.N. Mosher, K.W. Corscadden, Agriculture's contribution to the renewable energy sector: policy and economics – do they add up? Renew. Sustain. Energy Rev. 16 (2012) 4157–4164 https://doi.org/10.1016/j.rser.2012.03.027. [72] M.B. Sainz, Commercial cellulosic ethanol: the role of plant-expressed enzymes, Vitro Cell Dev. Biol. Plant 45 (2009) 314–329 https://doi.org/10.1007/s11627009-9210-1. [73] K.G. Roberts, B.A. Gloy, S. Joseph, N.R. Scott, J. Lehmann, Life cycle assessment of biochar systems: estimating the energetic, economic, and climate change potential, Environ. Sci. Technol. 44 (2010) 827–833 https://doi.org/10.1021/ es902266r. [74] H. Mu, X. Feng, K.H. Chu, Emergy synthesis of the agroecosystem in yan’an area of China, Agroecol. Sustain. Food Syst. 37 (2013) 1103–1119 https://doi.org/10. 1080/21683565.2013.772931. [75] S.B. McLaughlin, L. Adams Kszos, Development of switchgrass (Panicum virgatum) as a bioenergy feedstock in the United States, Biomass Bioenergy 28 (2005) 515–535 https://doi.org/10.1016/j.biombioe.2004.05.006. [76] A.M.I. Kallio, O. Salminen, R. Sievänen, Sequester or substitute—consequences of increased production of wood based energy on the carbon balance in Finland, J. For. Econ., Forests, wood and climate: New results in forest sector modeling 19 (2013) 402–415 https://doi.org/10.1016/j.jfe.2013.05.001. [77] D. Pimentel, Ethanol fuels: energy security, economics, and the environment, J. Agric. Environ. Ethics 4 (1991) 1–13 https://doi.org/10.1007/BF02229143. [78] Q. Yang, B. Chen, X. Ji, Y.F. He, G.Q. Chen, Exergetic evaluation of corn-ethanol production in China, Commun. Nonlinear Sci. Numer. Simulat. 14 (2009) 2450–2461 https://doi.org/10.1016/j.cnsns.2007.08.011. [79] H. Xian, G. Colson, B. Karali, M. Wetzstein, Do nonrenewable-energy prices affect renewable-energy volatility? The case of wood pellets, J. For. Econ. 28 (2017) 42–48 https://doi.org/10.1016/j.jfe.2017.05.004. [80] J. Song, B.M. Gramig, R. Cibin, I. Chaubey, Integrated economic and environmental assessment of cellulosic biofuel production in an agricultural watershed, BioEnergy Res 10 (2017) 509–524 https://doi.org/10.1007/s12155-017-9817-8. [81] V.A. Lantz, W.-Y. Chang, C. Pharo, Benefit-cost analysis of hybrid willow crop production on agricultural land in eastern Canada: assessing opportunities for onfarm and off-farm bioenergy use, Biomass Bioenergy 63 (2014) 257–267 https:// doi.org/10.1016/j.biombioe.2014.01.027. [82] D.F. Barnes, W.M. Floor, RURAL energy IN developing countries: a challenge for economic development, Annu. Rev. Energy Environ. 21 (1996) 497–530 https:// doi.org/10.1146/annurev.energy.21.1.497. [83] K. Kaygusuz, Hydropower and biomass as renewable energy sources in Turkey, Energy Sources 23 (2001) 775–799 https://doi.org/10.1080/ 009083101316931861. [84] K. Kaygusuz, M.F. Türker, Review of biomass energy in Turkey, Energy Sources 24 (2002) 383–401 https://doi.org/10.1080/00908310252889898. [85] L. He, B.C. English, D.G. De La Torre Ugarte, D.G. Hodges, Woody biomass potential for energy feedstock in United States, J. For. Econ. 20 (2014) 174–191 https://doi.org/10.1016/j.jfe.2014.04.002. [86] E. Geijer, J. Andersson, G. Bostedt, R. Brännlund, J. Hjältén, Safeguarding species richness vs. increasing the use of renewable energy—the effect of stump harvesting on two environmental goals, J. For. Econ. 20 (2014) 111–125 https://doi. org/10.1016/j.jfe.2014.01.001. [87] N.M. Tarr, M.J. Rubino, J.K. Costanza, A.J. McKerrow, J.A. Collazo, R.C. Abt, Projected gains and losses of wildlife habitat from bioenergy-induced landscape change, GCB Bioenergy 9 (2017) 909–923 https://doi.org/10.1111/gcbb.12383. [88] C.-L. Jin, Z.-M. Wu, S.-W. Wang, Z.-Q. Cai, T. Chen, M.R. Farahani, D.-X. Li, Economic assessment of biomass gasification and pyrolysis: a review, Energy Sources B Energy Econ. Plann. 12 (2017) 1030–1035 https://doi.org/10.1080/ 15567249.2017.1358309. [89] C. Cheng, Z. Liu, Z. Guo, N. Debnath, Waste-to-energy policy in China: a national strategy for management of domestic energy reserves, Energy Sources B Energy Econ. Plann. 12 (2017) 925–929 https://doi.org/10.1080/15567249.2017. 1324535. [90] S.C. Brechbill, W.E. Tyner, K.E. Ileleji, The economics of biomass collection and transportation and its supply to Indiana cellulosic and electric utility facilities, BioEnergy Res 4 (2011) 141–152 https://doi.org/10.1007/s12155-010-9108-0. [91] N. Magagnotti, R. Spinelli, Financial and energy cost of low-impact wood extraction in environmentally sensitive areas, Ecol. Eng. 37 (2011) 601–606 https:// doi.org/10.1016/j.ecoleng.2010.12.021. [92] M. Özilgen, E. Sorgüven, Energy and exergy utilization, and carbon dioxide emission in vegetable oil production, Energy 36 (2011) 5954–5967 https://doi. org/10.1016/j.energy.2011.08.020. [93] E. Sorgüven, M. Özilgen, Energy utilization, carbon dioxide emission, and exergy loss in flavored yogurt production process, Energy 40 (2012) 214–225 https://doi. org/10.1016/j.energy.2012.02.003. [94] G.S. Latta, J.S. Baker, R.H. Beach, S.K. Rose, B.A. McCarl, A multi-sector intertemporal optimization approach to assess the GHG implications of U.S. forest and agricultural biomass electricity expansion, J. For. Econ., Forests, wood and climate: New results in forest sector modeling 19 (2013) 361–383 https://doi.org/ 10.1016/j.jfe.2013.05.003.

economic analysis of fossil fuel substitution and carbon sequestration benefits, Agrofor. Syst. 59 (2003) 85–95 https://doi.org/10.1023/A:1026145321640. V. Dornburg, A. Faaij, M. Patel, W.C. Turkenburg, Economics and GHG emission reduction of a PLA bio-refinery system—combining bottom-up analysis with price elasticity effects, Resour. Conserv. Recycl. 46 (2006) 377–409 https://doi.org/10. 1016/j.resconrec.2005.08.006. R.J. Hanes, V. Gopalakrishnan, B.R. Bakshi, Synergies and trade-offs in renewable energy landscapes: balancing energy production with economics and ecosystem services, Appl. Energy 199 (2017) 25–44 https://doi.org/10.1016/j.apenergy. 2017.04.081. C.M. Regan, J.D. Connor, R. Raja Segaran, W.S. Meyer, B.A. Bryan, B. Ostendorf, Climate change and the economics of biomass energy feedstocks in semi-arid agricultural landscapes: a spatially explicit real options analysis, J. Environ. Manag. 192 (2017) 171–183 https://doi.org/10.1016/j.jenvman.2017.01.049. A. Chel, G. Kaushik, Renewable energy for sustainable agriculture, Agron. Sustain. Dev. 31 (2011) 91–118 https://doi.org/10.1051/agro/2010029. G.D. Sparks, G.F. Ortmann, Global biofuel policies: a review, Agrekon 50 (2011) 59–82 https://doi.org/10.1080/03031853.2011.589983. J. Singh, Management of the agricultural biomass on decentralized basis for producing sustainable power in India, J. Clean. Prod. 142 (2017) 3985–4000 https:// doi.org/10.1016/j.jclepro.2016.10.056. B. Amigun, R. Sigamoney, H. von Blottnitz, Commercialisation of biofuel industry in Africa: a review, Renew. Sustain. Energy Rev. 12 (2008) 690–711 https://doi. org/10.1016/j.rser.2006.10.019. J. Leboreiro, A.K. Hilaly, Biomass transportation model and optimum plant size for the production of ethanol, Bioresour. Technol. 102 (2011) 2712–2723 https://doi. org/10.1016/j.biortech.2010.10.144. Ö. Yildiz, J. Rommel, S. Debor, L. Holstenkamp, F. Mey, J.R. Müller, J. Radtke, J. Rognli, Renewable energy cooperatives as gatekeepers or facilitators? Recent developments in Germany and a multidisciplinary research agenda, Energy Res. Soc. Sci. 6 (2015) 59–73 https://doi.org/10.1016/j.erss.2014.12.001. M.P. McHenry, Carbon-based stock feed additives: a research methodology that explores ecologically delivered C biosequestration, alongside live weights, feed use efficiency, soil nutrient retention, and perennial fodder plantations, J. Sci. Food Agric. 90 (2010) 183–187 https://doi.org/10.1002/jsfa.3818. T. Abbas, G. Ali, S.A. Adil, M.K. Bashir, M.A. Kamran, Economic analysis of biogas adoption technology by rural farmers: the case of Faisalabad district in Pakistan, Renew. Energy 107 (2017) 431–439 https://doi.org/10.1016/j.renene.2017.01. 060. D. Clancy, J.P. Breen, F. Thorne, M. Wallace, A stochastic analysis of the decision to produce biomass crops in Ireland, Biomass Bioenergy, International Conference on Lignocellulosic ethanol 46 (2012) 353–365 https://doi.org/10.1016/j. biombioe.2012.08.005. E. Gnansounou, A. Dauriat, C.E. Wyman, Refining sweet sorghum to ethanol and sugar: economic trade-offs in the context of North China, Bioresour. Technol. 96 (2005) 985–1002 https://doi.org/10.1016/j.biortech.2004.09.015. X. Liu, Vivian, S.K. Hoekman, A. Broch, Potential water requirements of increased ethanol fuel in the USA, Energy Sustain. Soc. 7 (2017) 18 https://doi.org/10. 1186/s13705-017-0121-4. X. Liu, S. Zhang, J. Bae, The impact of renewable energy and agriculture on carbon dioxide emissions: investigating the environmental Kuznets curve in four selected ASEAN countries, J. Clean. Prod. 164 (2017) 1239–1247 https://doi.org/10. 1016/j.jclepro.2017.07.086. B. Coulman, A. Dalai, E. Heaton, C.P. Lee, M. Lefsrud, D. Levin, P.G. Lemaux, D. Neale, S.P. Shoemaker, J. Singh, D.L. Smith, J.K. Whalen, Developments in crops and management systems to improve lignocellulosic feedstock production, Biofuels Bioprod. Biorefining 7 (2013) 582–601 https://doi.org/10.1002/bbb. 1418. J.H. Reif, W. Alhalabi, Solar-thermal powered desalination: its significant challenges and potential, Renew. Sustain. Energy Rev. 48 (2015) 152–165 https://doi. org/10.1016/j.rser.2015.03.065. M.M. Gui, K.T. Lee, S. Bhatia, Feasibility of edible oil vs. non-edible oil vs. waste edible oil as biodiesel feedstock, Energy 33 (2008) 1646–1653 https://doi.org/10. 1016/j.energy.2008.06.002. B.A. Bryan, D. King, E. Wang, Biofuels agriculture: landscape-scale trade-offs between fuel, economics, carbon, energy, food, and fiber, GCB Bioenergy 2 (2010) 330–345 https://doi.org/10.1111/j.1757-1707.2010.01056.x. W.-C. Wang, L. Tao, Bio-jet fuel conversion technologies, Renew. Sustain. Energy Rev. 53 (2016) 801–822 https://doi.org/10.1016/j.rser.2015.09.016. D.D.L.T. Ugarte, L. He, Is the expansion of biofuels at odds with the food security of developing countries? Biofuels Bioprod. Biorefining 1 (2007) 92–102 https:// doi.org/10.1002/bbb.16. E. Krasuska, H. Rosenqvist, Economics of energy crops in Poland today and in the future, Biomass Bioenergy, Overcoming Barriers to Bioenergy: Outcomes of the Bioenergy Network of Excellence 2003 – 2009 38 (2012) 23–33 https://doi.org/ 10.1016/j.biombioe.2011.09.011. T. Thewys, N. Witters, E. Meers, J. Vangronsveld, Economic viability of phytoremediation of a cadmium contaminated agricultural area using energy maize. Part II: economics of anaerobic digestion of metal contaminated maize in Belgium, Int. J. Phytoremediation 12 (2010) 663–679 https://doi.org/10.1080/15226514. 2010.493188. K. Ericsson, H. Rosenqvist, E. Ganko, M. Pisarek, L. Nilsson, An agro-economic analysis of willow cultivation in Poland, Biomass Bioenergy 30 (2006) 16–27 https://doi.org/10.1016/j.biombioe.2005.09.002. K.W. Corscadden, J.N. Biggs, D.K. Stiles, Sheep's wool insulation: a sustainable alternative use for a renewable resource? Resour. Conserv. Recycl. 86 (2014) 9–15

408

Energy Strategy Reviews 22 (2018) 396–409

V.J.P.D. Martinho

[95] A. Moiseyev, B. Solberg, A.M.I. Kallio, Wood biomass use for energy in Europe under different assumptions of coal, gas and CO2 emission prices and market conditions, J. For. Econ., Forests, wood and climate: New results in forest sector modeling 19 (2013) 432–449 https://doi.org/10.1016/j.jfe.2013.10.001. [96] H. Dinesh, J.M. Pearce, The potential of agrivoltaic systems, Renew. Sustain. Energy Rev. 54 (2016) 299–308 https://doi.org/10.1016/j.rser.2015.10.024. [97] S. Ravi, J. Macknick, D. Lobell, C. Field, K. Ganesan, R. Jain, M. Elchinger, B. Stoltenberg, Colocation opportunities for large solar infrastructures and agriculture in drylands, Appl. Energy 165 (2016) 383–392 https://doi.org/10.1016/j. apenergy.2015.12.078. [98] R.P. Zentner, C.A. Campbell, V.O. Biederbeck, P.R. Miller, F. Selles, M.R. Fernandez, In search of a sustainable cropping system for the semiarid canadian prairies, J. Sustain. Agric. 18 (2001) 117–136 https://doi.org/10.1300/ J064v18n02_10. [99] Y. l Chen, Y. w Han, J. x Gao, M. r Tian, Emergy depletion and offset of fossil energy assets in China, 2009 International Conference on Environmental Science and Information Application Technology. Presented at the 2009 International Conference on Environmental Science and Information Application Technology, 2009, pp. 3–7 https://doi.org/10.1109/ESIAT.2009.264. [100] J.S. Gregg, S.J. Smith, Global and regional potential for bioenergy from agricultural and forestry residue biomass, Mitig. Adapt. Strategies Glob. Change 15 (2010) 241–262 https://doi.org/10.1007/s11027-010-9215-4. [101] I.O.A. Odeh, D.K.Y. Tan, T. Ancev, Potential suitability and viability of selected biodiesel crops in australian marginal agricultural lands under current and future climates, BioEnergy Res 4 (2011) 165–179 https://doi.org/10.1007/s12155-0109110-6. [102] Web of Science, Web of science - all databases, WWW Document http://apps. webofknowledge.com/UA_GeneralSearch_input.do?product=UA&SID= E3HCSavurrLgvZUeyZY&search_mode=GeneralSearch, (2018) , Accessed date: 8 October 2018. [103] Scopus, Scopus database, WWW Document https://www.scopus.com/home.uri, (2018) , Accessed date: 8 October 2018. [104] G. Chinnici, M. D'Amico, M. Rizzo, B. Pecorino, Analysis of biomass availability for

[105]

[106]

[107] [108]

[109] [110] [111]

[112]

[113]

[114] [115]

409

energy use in Sicily, Renew. Sustain. Energy Rev. 52 (2015) 1025–1030 https:// doi.org/10.1016/j.rser.2015.07.174. G. Chinnici, R. Selvaggi, M. D'Amico, B. Pecorino, Assessment of the potential energy supply and biomethane from the anaerobic digestion of agro-food feedstocks in Sicily, Renew. Sustain. Energy Rev. 82 (2018) 6–13 https://doi.org/10. 1016/j.rser.2017.09.018. J.C. Reboredo, Do food and oil prices co-move? Energy policy, special section, Fuel Poverty Comes of Age: Commemorating 21 Years of Research and Policy 49 (2012) 456–467 https://doi.org/10.1016/j.enpol.2012.06.035. H. de Gorter, D. Drabik, D.R. Just, The Economics of Biofuel Policies - Impacts on Price Volatility in Grain and Oilseed Markets, Palgrave Macmillan US, 2015. J. Popp, M. Harangi-Rákos, Z. Gabnai, P. Balogh, G. Antal, A. Bai, Biofuels and their Co-products as livestock feed: global economic and environmental implications, Mol. Basel Switz. 21 (2016) 285 https://doi.org/10.3390/ molecules21030285. C.L. Gilbert, How to understand high food prices, J. Agric. Econ. 61 (2010) 398–425 https://doi.org/10.1111/j.1477-9552.2010.00248.x. C.L. Gilbert, H.K. Mugera, Food commodity prices volatility: the role of biofuels, Nat. Resour. 05 (2014) 200 https://doi.org/10.4236/nr.2014.55019. J.W.A. Langeveld, J. Dixon, H. van Keulen, P.M.F. Quist‐Wessel, Analyzing the effect of biofuel expansion on land use in major producing countries: evidence of increased multiple cropping, Biofuels Bioprod. Biorefining 8 (2014) 49–58 https:// doi.org/10.1002/bbb.1432. D. Zilberman, G. Hochman, D. Rajagopal, S. Sexton, G. Timilsina, The impact of biofuels on commodity food prices: assessment of findings, Am. J. Agric. Econ. 95 (2013) 275–281 https://doi.org/10.1093/ajae/aas037. X. Chen, H. Önal, Renewable energy policies and competition for biomass: implications for land use, food prices, and processing industry, Energy Pol. 92 (2016) 270–278 https://doi.org/10.1016/j.enpol.2016.02.022. J. Popp, S. Kot, Z. Lakner, J. Oláh, Biofuel use: peculiarities and implications, J. Secur. Sustain. Issues 7 (2018), https://doi.org/10.9770/jssi.2018.7.3(9. R. Cullen, Evaluating renewable energy policies, Aust. J. Agric. Resour. Econ. 61 (2017) 1–18.