The economic effects of energetic exploitation of straw in Vojvodina

The autonomous province of Vojvodina is an autonomous province in the Republic of Serbia. It is located in the northern part of the country, in the Pannonia plain. Vojvodina is an energy-deficient province.Assessment of the effects of energetic use wheat straw is performed for certain types of systems for storing straw and straw stored specifically in the form of small square bales, and especially for the cylinder-shaped straw bales. The method of evaluation of economic effects is based on the total cost of collecting, transportation, handling and storing, with corrections for the difference in the cost of the energy conversion and combustion.With comparison of the costs of energy production from baled straw to the costs of energy production from hard coal, it was found that the energy obtained from the straw from own farm is cheaper than energy from hard coal by 28%, in the case of the using small square bales and by 34% in the case of the using cylinder-shaped bales. Through sensitivity analysis it was concluded that the two systems of collecting straw, economically, are relatively resistant to changes in prices of the most important inputs. However, there is a relatively high sensitivity to changes in performances of machines with a larger percentage increase of costs for the system with cylinder-shaped bales. However, this system is generally more resistant to changes of influencing factors due to lower basic costs per ton of the pretreated straw. Differential costs analysis, i.e., the development of differential calculations, shows that the energy from straw in the form of small square bales is cheaper than the energy from hard coal by 51%, while the energy from the straw in the form cylinder-shaped bales is cheaper by 60%.     

The boiler concept for combustion of large soya straw bales

In one of the largest agricultural companies in Serbia, with over 2000 ha of soya plantations, there are 4000 t/year of baled soya straw produced. Soya straw biomass is planned to be used as a renewable energy source for heating the greenhouses, with 5 ha in area. Therefore, efforts have been made to develop a technology for utilizing large bales of soya straw for energy production. In the first phase, a demo energy production facility-furnace was developed and built. The facility had been tested in order to examine the quality of combustion of large soya straw bales. Since experimental results of testing of this facility have proved to be very satisfactory, in the second phase of the development, a hot water boiler of similar characteristics (burning soya straw bales, with dimensions 0.7×1.2×2.7 m³) has been designed.     

Serbian gas sector in the spotlight of oil and gas agreement with Russia

The Russian natural gas industry is the world's largest producer and transporter of natural gas. This paper identifies the benefits for Serbia as transient country to European Union for Russian natural gas through South Stream gas-line in the current political context of implementation of gas agreement. On the other hand, according to the Agreement on Stabilization and Integration to European Union, Serbia is obligatory to implement reforms in energy sector and its energy policy must be in accordance with the European Union policy. Republic of Serbia has produced and consumed natural gas domestically since 1952, but has always been net importer. Strategy of Energy Development in Serbia and especially, National Action Plan for the gasification on the territory of Republic of Serbia dedicated special attention to gas economy development in respect with expected contribution in efficient energy use and environmental policy protection in the country.     

The analysis of the renewable energy production sector in Serbia

Producing energy from renewable sources in Serbia is in its initial phase, and therefore this paper points towards the basic assumptions, potentials and institutional framework for the development of this activity in Serbia. Until recently, production and consumption of energy in Serbia was a social category, but the shift towards market economy together with the fact that Serbia has adopted Kyoto protocol, production of energy from renewable sources became a competitive and obligatory activity. Research shows that the current potentials for producing energy from renewable sources in Serbia are favorable. Besides this, the paper provides an overview of the existing institutional structure in the energy sector in Serbia, but also the short overview of the adequate legal acts. Researches that were done so far have proven that energy potentials of Serbia are insufficiently known and therefore authors will give an overview of the foreign investments in this sector and reveal the possibilities for further investing. Considering the existing know-how base and potentials for the production of equipment, geothermal energy and energy coming from biomass have been identified as priority renewable sources of energy. Producing energy from other renewable sources is also possible, but would require substantial foreign investments. As a final conclusion, the paper states that completely unused potentials for production of energy from renewable sources, together with adequately set institutional framework, would create great possibilities for foreign investments.     

Limitations and improvement of the potential utilisation of woody biomass for energy derived from short rotation woody crops in Sweden and Germany

The use of biomass derived from fast-growing trees grown on agricultural land is common practice in parts of Sweden, but not in most other European countries. In the first part of this paper the different conditions for economic use of fast growing trees are analysed in Germany and Sweden. Neither the legal framework nor the natural growing conditions are likely to limit the utilisation of the biomass potential in Germany. Rather, lack of a market for biomass products, poor awareness and little infrastructure for the management of woody biomass plantations are limitations in Germany. The second part offers a possible solution for supporting the market and reducing transaction costs during establishment of the market under German conditions. The proposed solution involves the establishment of ‘ecological structures’ based on fast-growing trees as a means to compensate for sealed land by roads and buildings. The proposed concept would not only extend the economic potential for producing energy from biomass, but also allow farmers to generate income. The concept can serve both economic and ecological goals. It can reduce municipal budget funding and support the agricultural industry in European countries which need to implement sustainable biomass concepts.     

Private forest owners' willingness to supply woody biomass in selected South-Eastern European countries

Production of woody biomass-based energy, mainly by using fuel wood, is a common way of forest utilization in selected South-Eastern European countries – Croatia, Bosnia-Herzegovina, Serbia and Former Yugoslav Republic of Macedonia. Due to specific forest ownership patterns in the region, state owned forests are the most important source of all forest assortments, including woody biomass. Having in mind the increasing energy needs on the global scale, particularly those for energy from renewable sources, private forests may play an important role in terms of wood mobilization and energy production from woody biomass. The purpose of this research was to identify the willingness of private forest owners in selected countries to supply woody biomass for energy as well as to identify the factors that influence it. The survey data collected in 2012 from 1.400 private forests owners (random samples of 350 private forests owners in each of the four countries), show a relatively high degree of willingness (38–55% of the respondents) to manage their forests in order to produce woody biomass. Furthermore, the results, demonstrated that the willingness of private forest owners to supply woody biomass was namely influenced by age in analysed countries. The models found that relatively younger owners were more likely to supply woody biomass. An adequate institutional and financial support to private forest owners and the designing of an appropriate mix of forest policy instruments are necessary for a better wood mobilisation and the triggering of woody biomass supply from private forests in selected South-Eastern European countries.     

Analysis of olive grove residual biomass potential for electric and thermal energy generation in Andalusia (Spain)

As fossil fuels are not only a limited resource, but also contribute to global warming, a transition towards a more sustainable energy supply is urgently needed. Therefore, today's environmental policies are largely devoted to fostering the development and implementation of renewable energy technologies. One important aspect of this transition is the increased use of biomass to generate renewable energy. Agricultural residues are produced in huge amounts worldwide, and most of this residue is composed of biomass that can be used for energy generation. Consequently, converting this residue into energy can increase the value of waste materials and reduce the environmental impact of waste disposal. This paper analyses the situation of biomass energy resources in Andalusia, an autonomous community in the south of Spain. More specifically, biomass is the renewable source which most contributes to Andalusian energy infrastructure. The residual biomass produced in the olive sector is the result of the large quantity of olive groves and olive oil manufacturers that generate byproducts with a potentially high energy content. The generation of agricultural and industrial residues from the olive sector produced in Andalusia is an important source of different types of residual biomass that are suitable for thermal and electric energy since they reduce the negative environmental effects of emissions from fossil fuels, such as the production of carbon dioxide.     

Prospects of wind energy sector development in Serbia with relevant regulatory framework overview

The growth of the renewable energy sector in the world in the first decade of the twenty-first century was rapid. Wind energy sector was one of the fastest growing renewable energy technologies. In this paper, authors have tried to review the current state of wind power utilization in Serbia as one of the most penetrating RES technologies in the world. The brief overview of electric power sector in Serbia was given in order to describe the environment for emerging wind energy sector development. Sufficient wind energy resources were identified in several regions of the country. Current energy policy in Serbia was reviewed in terms of the regulations that have to be followed in order to meet the requirements for RES power plants, i.e. wind power plant construction. In subsequent section short reviews of wind energy projects which are in their initial phases are provided. The wind energy sector in Serbia is emerging despite the difficulties faced by the investors, regulatory bodies and other shareholders, in the course of the past several years. There is an urgent need of a broader transfer of specific knowledge and technologies related to wind farms and wind turbines in order to speed up the current wind energy sector development.     

Kyoto Protocol implementation in Serbia as precognition of sustainable energetic and economic development

The paper gives reasons for low energy efficiency typical of the Serbian economy, which is based on outdated and dirty technologies. The comparison of selected economic indicators and indicators of energy efficiency in both Serbia and the European Union points out the benefits of the Kyoto Protocol implementation due to the growth of competitiveness in the global market. Serbia has no obligation to reduce GHG emissions, the authors point to the proposals whose implementation along with the mechanisms of the Protocol can enable Serbia the access to markets that trade GHG emissions and the access to dedicated funds, self-financing or attracting foreign investments to raise energy efficiency, which will be accompanied by adequate economic benefits. A similar principle can be applied in all countries that are not obliged to reduce GHG emissions. The application of different mechanisms aiming to increase energy efficiency in Serbia, could contribute to the increase of GDP annual growth rate from 5% to 7%, which cannot be achieved by any other economic instrument. Energy efficiency, which is actually a question of competitiveness of each economy, can finance itself through the mechanisms of the Kyoto Protocol by selling excess emissions resulting from improved energy efficiency.     

Sustainable utilisation of forest biomass for energy—Possibilities and problems: Policy,legislation, certification,and recommendations and guidelines in the Nordic,Baltic, and other European countries

The substitution of biomass for fossil fuels in energy consumption is a measure to mitigate global warming, as well as having other advantages. Political action plans for increased use exist at both European and national levels. This paper briefly reviews the contents of recommendations, guidelines, and other synthesis publications on sustainable use of forest biomass for energy. Topics are listed and an overview of advantages, disadvantages, and trade-offs between them is given, from the viewpoint of society in general and the forestry and energy sectors in particular. For the Nordic and Baltic countries, the paper also identifies the extent to which wood for energy is included in forest legislation and forest certification standards under the “Programme for the Endorsement of Forest Certification” (PEFC) and the “Forest Stewardship Council” (FSC) schemes. Energy and forest policies at EU and national levels, and European PEFC forest standards are analysed. With respect to energy policies, the utilisation of wood for energy is generally supported in forest policies, but forest legislation is seldom used as a direct tool to encourage the utilisation of wood for energy. Regulations sometimes restrict use for environmental reasons. Forest certification standards include indicators directly related to the utilisation of wood for energy under several criteria, with most occurrences found under environmental criteria. Roles and problems in relation to policy, legislation, certification standards, recommendations and guidelines, and science are discussed.     

Exploitation of geothermal energy as a priority of sustainable energetic development in Serbia

The actual global economic crisis, including all other well-known problems of sustainable development, reflects the direction of development of all countries in the world. Serbia, as a European country in its early stage of development, is trying to synchronize its progress with experience of other countries from the field of sustainable development and in accordance with rules in the field of energetic and energetic efficiency, and, as well as to promote and develop the sector of use of renewable sources of energy. On the other hand, Serbia is a country which largely depends on import of all forms of energy, which to a great extent affects its economic stability. Therefore, in Serbia the strategy for development of energetic was imposed and it considers all the aspects of development of energetic until 2015 and it also defines the priorities which can be mostly seen in the choice of forms of alternative sources of energy. These sources, based on some criteria, can be considered the most convenient for a gradual substitution of energy which is gotten from the conventional sources. Taking into account strategically defined goals and domestic potentials which are at disposal, as well as economic parameters, an alternative source of energy of basic importance for the future exploitation on the territory of Serbia geothermal energy, was chosen. The research points to the fact that Serbia will be capable to respond adequately to Kyoto protocol demands and to the European rules regarding the substitution of a certain amounts of fossil fuels by the fuel origin from the raw biological materials. The research defines the existent and non-existent capacities and the assessment of positive effects of usage of geothermal energy. At the moment, 160 long holes are being exploited whose water temperature is around 60 °C (140 °F) and their heat power reach 160 MJ/s. It was stated that adequate exploitation of existing and new geothermal sources a yearly would save about 500,000 tons of fossil fuels what is proportional to the 10% of the today's heating system. The total amount of heat accumulated at geothermal deposit sites in Serbia, up to 3 km of depth, is two times greater than the total amount of heat that may be generated by burring all available coal reserves in Serbia. Price of electrical energy produced from geothermal springs is estimated to be between 9.2 US cents/kWh and 11.5 US cents/kWh. In order to support exploitation of geothermal energy (as well as all other renewable sources of energy) the decision that all the producers of energy from renewable sources get a status of privileged producers were made.     

A biomass energy flow chart for Sierra Leone

Terrestrial above-ground biomass production and utilisation in Sierra Leone was analysed for the years 1984/5 to 1990/1. The total production of biomass energy was estimated at an annual average of 131 PJ (39% from agriculture, 51% from forestry and 10% from livestock). Of the 117 PJ produced from agricultural and forestry operations, 37 PJ was harvested as firewood and burnt (10.9 GJ or 0.72 t wood per capita per year, supplying 80% of the country’s energy), 12 PJ was harvested for food, 66 PJ was unutilised crop and forestry residues, 3 PJ was harvested crop residues for use directly as fuel, and 2 PJ was harvested and used for industrial purposes and not for fuel. Livestock produced wastes with an energy content of 13 PJ of which only 0.1 PJ was collected and used for fuel. Thus 54 PJ (41%) of the 131 PJ of biomass energy produced annually was actually utilised while 49 PJ remained as unused agricultural residues and dung, and a further 27 PJ was unused forestry residues. The total amount of biomass (fuelwood, residues and dung) used directly to provide energy, mostly in households, was estimated at 40 PJ (11.8 GJ per capita per year or 0.79 t fuelwood equivalent). Direct biomass energy utilisation in agroindustry (0.4 PJ) was negligible in comparison.Two assessments of Sierra Leone’s biomass standing stock and MAI (mean annual increment) were examined in order to assess the sustainability of various biomass use scenarios. Large differences were found between the MAI of the two assessments, making it difficult to predict sustainability of biomass production and use. The estimation of total standing stock varied between 227 and 366 Mt and the estimation of MAI varied between 15 and 70 Mt.Analysis of the availability and use of the biomass resource is crucial if biomass energy is to be used on a sustainable basis. A software package has been developed and is available to draft biomass flow charts but further work is needed to incorporate social and economic costs.     

On the feasibility of direct hydrogen utilisation in a fossil-free Europe

Hydrogen is often suggested as a universal fuel that can replace fossil fuels. This paper analyses the feasibility of direct hydrogen utilisation in all energy sectors in a 100% renewable energy system for Europe in 2050 using hour-by-hour energy system analysis. Our results show that using hydrogen for heating purposes has high costs and low energy efficiency. Hydrogen for electricity production is beneficial only in limited quantities to restrict biomass consumption, but increases the system costs due to losses. The transport sector results show that hydrogen is an expensive alternative to liquid e-fuels and electrified transport due to high infrastructure costs and respectively low energy efficiency. The industry sector may benefit from hydrogen to reduce biomass at a lower cost than in the other energy sectors, but electrification and e-methane may be more feasible. Seen from a systems perspective, hydrogen will play a key role in future renewable energy systems, but primarily as e-fuel feedstock rather than direct end-fuel in the hard-to-abate sectors.     

Reliability based socio economic optimal renewable energy model for India

Renewable energy sources such as solar, wind and biomass have to play a vital role in the developing countries like India in order to meet the growing energy demand. In the last five years, some renewable energy sources had emerged as technically and economically viable alternatives in the energy sector, as a result, more ambitious plans for their dissemination were being launched. In this situation, development of an energy model exclusively for renewables will help in the allocation of appropriate renewable energy systems for different end-uses in the future. An attempt has been made to develop a reliability based socio economic optimal renewable energy model for India in the year 2020–2021. The effect of social acceptance variation in OREM model was analysed. The lighting end-use would be met by solar PV and biogas system to an extent of 0.5198×10¹⁵ kJ and 0.75×10¹⁵ kJ, respectively. Similarly, the renewable energy utilisation is found for other end-uses.     

Hydro energy potential of cooling water at the thermal power plant

The hydro energy of the gravity water flow from the coal-fired thermal power plant units to the river in an open cooling system of turbine condensers is determined. On the basis of statistical data for a long time period, the water net head duration curve due to the river annual level change, as well as the reduction of the hydro energy potential due to the thermal power plant overhauls periods, are evaluated in the case study of the Thermal Power Plant “Nikola Tesla B” in Serbia. A small hydro power plant is designed for the utilization of this hydro energy, and the economic benefits of the project are calculated. The internal rate of returns and pay back periods are calculated in dependence of the electricity price and total investment costs. The increase of profitability is assessed, bearing in mind that the plant might be realized as the Clean Development Mechanism project according to the Kyoto protocol. The obtained results show that the project is economically attractive, and it can be carried out with standard matured solutions of hydro turbines available at the market. Even for the relatively low electricity price from small hydro power plants in Serbia of 0.08 €/kW h the internal rate of return and the pay back period are 17.5% and 5.5 years.     

World trade in forest products and wood fuel

Wood fuel is a strategic resource for future energy supply and is usually utilised locally. Traditional use of wood fuel and other bioenergy has a share of 10–15% energy supply, used mainly for the household sector. The utilisation for industrial purposes is much smaller but is a strategic resource in the effort to fulfil the Kyoto agreement to replace fossil fuels and to mitigate greenhouse gas emissions. Many industrialised countries already use a significant share of biofuels in their energy supply e.g. Nordic countries while others like some other European Union countries are planning to increase their use. Production and use of biofuels need to be carried out sustainable. Official statistics do not report trade in such detail that international trade in different biomass types can be fully identified. However, FAO and European Forestry Institute are important sources. In some countries, there is a growing interest in the international trade, because the trade can provide biofuels at lower prices, larger quantities and better quality than domestic alternatives. The first signs of an international market price for wood fuel are indicated in Europe. For the future both the use and the trade of wood fuel is expected to increase. Analyses for trade in charcoal, wood chips, fuel wood and wood residues made in this report identify ‘hot’ trade spots in Europe, in south East Asia and in North America.     

Progress and recent trends in biofuels

In this paper, the modern biomass-based transportation fuels such as fuels from Fischer–Tropsch synthesis, bioethanol, fatty acid (m)ethylester, biomethanol, and biohydrogen are briefly reviewed. Here, the term biofuel is referred to as liquid or gaseous fuels for the transport sector that are predominantly produced from biomass. There are several reasons for bio-fuels to be considered as relevant technologies by both developing and industrialized countries. They include energy security reasons, environmental concerns, foreign exchange savings, and socioeconomic issues related to the rural sector. The term modern biomass is generally used to describe the traditional biomass use through the efficient and clean combustion technologies and sustained supply of biomass resources, environmentally sound and competitive fuels, heat and electricity using modern conversion technologies. Modern biomass can be used for the generation of electricity and heat. Bioethanol and biodiesel as well as diesel produced from biomass by Fischer–Tropsch synthesis are the most modern biomass-based transportation fuels. Bio-ethanol is a petrol additive/substitute. It is possible that wood, straw and even household wastes may be economically converted to bio-ethanol. Bio-ethanol is derived from alcoholic fermentation of sucrose or simple sugars, which are produced from biomass by hydrolysis process. Currently crops generating starch, sugar or oil are the basis for transport fuel production. There has been renewed interest in the use of vegetable oils for making biodiesel due to its less polluting and renewable nature as against the conventional petroleum diesel fuel. Biodiesel is a renewable replacement to petroleum-based diesel. Biomass energy conversion facilities are important for obtaining bio-oil. Pyrolysis is the most important process among the thermal conversion processes of biomass. Brief summaries of the basic concepts involved in the thermochemical conversions of biomass fuels are presented. The percentage share of biomass was 62.1% of the total renewable energy sources in 1995. The reduction of greenhouse gases pollution is the main advantage of utilizing biomass energy.     

Establishing perennial grass energy crops in the UK: A review of current propagation options for Miscanthus

A key UK government strategy is to expand the supply of home grown biomass and facilitate the development and competitiveness of a sustainable supply chain, while promoting low-carbon technology. Analysis of the potential supply chain suggests that this can, in part, be achieved by growing energy crops. Meeting expectations is, however, reliant on developing an economically viable biomass sector which incorporates efficient, sustainable and regional supply chains to increase biomass use.This review aims to present the knowledge by which plant propagules, for the biomass supply chain, can be produced at minimum cost. It specifically addresses the potential of biomass production from the perennial grass Miscanthus. This review is part of a project to identify the causes for the apparent limitations in the establishment of UK perennial energy crops. The work reported here focuses on the knowledge available regarding the potential routes by which Miscanthus material could be mass produced.The review concludes that high density plantings must be established to maximise yields. Vegetative clonal plant propagation is required to deliver uniform crops of selected germplasm. Commercial seed production in the UK is not possible and potentially undesirable for selected germplasm. Rhizome production and division is slow, but currently does not limit increases in production because the UK industry uptake is currently small. Uptake of new germplasm will be dependent on the use of rapid and cost effective plant propagation systems, particularly vegetative systems. The germplasm collection established provides an opportunity for genotypes to be propagated by a range of techniques to determine ease of propagation in terms of cost and multiplication rates. At present the establishment rate of Miscanthus is slow and this appears limited by economics; evidence suggests that the cost of plant propagules is one factor that constrains widespread planting. New techniques are required that simultaneously reduce unit costs of propagules and increase the speed of their availability to aid this developing industry.     

Possibility of efficient utilization of wood waste as a renewable energy resource in Serbia

Wood biomass in Serbia is traditionally used for energy. However, the manner of its use is outdated, and efficiency is very low. Annually over 3.5 million m³ of wood is cut down for energy needs in Serbia. In order to better exploit all forms of woody biomass, especially the one that is now treated as waste, and in order to fulfil the obligations from the outlined Convention on Climate Change it is necessary to switch to a modern way of production and utilization of woody biomass. Serbia is now at the very beginning of this process. This paper gives an overview and an analysis of the possibilities of utilization of wood waste as a renewable source of energy and the problems that producers in Serbia are facing due to undeveloped markets and excessive funds that are needed to start the production of briquettes and pellets. The ecological and economical advantages of using woody biomass, as well the possible support measures for the use of woody biomass in Serbia are also the topic of this paper. The present situation in this area, the manner of waste management in sawmills and the reasons for the necessity of future development of this industrial production are also briefly described.     

Experimental method for determining Forchheimer equation coefficients related to flow of air through the bales of soy straw

The paper presents results of experimental investigation conducted to determine permeability coefficient of a porous bed formed by biomass bales, whereby the said coefficient represents one of the most important parameters of the bed material specified when considering its combustion in the pusher-type furnaces (i.e. combustion of biomass bales in cigar burners). Correlations obtained are deemed very important for optimization of biomass bale combustion, as well as for modeling transport phenomena occurring in the porous bed formed by biomass bales during their combustion in cigar burners.In order to determine permeability coefficient of air flow through soy straw bales, appropriate experimental method was developed and suitable experimental apparatus designed and constructed. The relevant coefficients were determined in such manner as to be representative of the viscous and inertial terms of the Forchheimer equation. Experimental investigation conducted examined the effects of relevant biomass bale parameters i.e. porosity and the moisture content on the abovementioned Forchheimer coefficients. Measurements conducted, as well as analysis of the results obtained, defined functional dependencies of the permeability coefficients on the porosity (which was varied in the range 0.62–0.78, for moisture content of 0.0948) and the sample’s moisture content (which was varied in the range 0.0948–0.6394, for the selected value of porosity of 0.68) to be established. The correlations obtained are deemed suitable to be used in a broad spectrum of operating conditions that usually occur during real operation.Results obtained indicate that reduction in biomass bed porosity results in reduced permeability, with Forchheimer coefficients exhibiting a hyperbolic dependence on the bed porosity. Since it has been observed that increased moisture content of the sample (porosity value of 0.68) caused a decrease in permeability, a functional dependence of the sample moisture content on the porosity has been established. The dependence established is valid for the range of the sample moisture content between 0.0948 and 0.6394.Permeability coefficients, as well as their dependencies on the relevant factors (porosity and moisture content), represent basic data used in mathematical modeling of biomass bale combustion in cigar burners. In addition, the ones may also be very important when considering modifications of furnaces utilizing the combustion principle mentioned.