| 1. |
- Neij, Lena
(författare)
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Dynamics of Energy Systems - Methods of analysing technology change
- 1999
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Technology change will have a central role in achieving a sustainable energy system. This calls for methods of analysing the dynamics of energy systems in view of technology change and policy instruments for effecting and accelerating technology change. In this thesis, such methods have been developed, applied, and assessed. Two types of methods have been considered, methods of analysing and projecting the dynamics of future technology change and methods of evaluating policy instruments effecting technology change, i.e. market transformation programmes. Two methods are focused on analysing the dynamics of future technology change; vintage models and experience curves. Vintage models, which allow for complex analysis of annual streams of energy and technological investments, are applied to the analysis of the time dynamics of electricity demand for lighting and air-distribution in Sweden. The results of the analyses show that the Swedish electricity demand for these purposes could decrease over time, relative to a reference scenario, if policy instruments are used. Experience curves are used to provide insight into the prospects of diffusion of wind turbines and photo voltaic (PV) modules due to cost reduction. The results show potential for considerable cost reduction for wind-generated electricity, which, in turn, could lead to major diffusion of wind turbines. The results also show that major diffusion of PV modules, and a reduction of PV generated electricity down to the level of conventional base-load electricity, will depend on large investments in bringing the costs down (through RD&D, market incentives and investments in niche markets) or the introduction of new generations of PV modules (e.g. high-efficiency mass-produced thin-film cells). Moreover, a model has been developed for the evaluation of market transformation programmes, i.e. policy instruments that effect technology change and the introduction and commercialisation of energy-efficient technologies. The method of evaluation has been applied to assess methods used to evaluate Swedish market transformation programmes. The evaluation model, and the assessment of the Swedish evaluation methods, illustrates a need for more extensive evaluation methods than those used today.
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| 2. |
- Salay, Jürgen
(författare)
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Energy Use, Efficiency Gains and Emission Abatement in Transitional Industrialised Economies: Poland and the Baltic States
- 1999
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- This thesis is a study of how energy use and air pollution in Poland, Estonia, Latvia and Lithuania have been affected by the economic transition after 1989. It consists of six articles, which examine three different aspects of these changes. The first group of articles analyses the structure of energy use in the Baltic states (Article I) and Poland Articles II and III) at the outset of transition. The results show that these countries had a primary energy consumption per GDP which was two to three times higher than in developed market economies because of a more energy intensive structure of the economy and higher specific energy intensities in many sectors of the economy. They also had significantly higher levels of air pollution per primary energy consumption and GDP because of a heavy reliance on fossil fuels, an energy intensive economy and an ineffective control of emissions. The deep fall in energy consumption during the first phase of transition was due to a sharp drop in industrial output and higher fuel prices. In the Baltic states, part of the fall in energy consumption was the result of shortfalls in the supply of oil and gas from Russia. The second group of articles (Articles IV and V) examines changes in electricity production, fuel consumption, generation efficiency and sulphur dioxide (SO2) emissions in the Polish power industry between 1988 and 1997. The results show that SO2 emissions dropped by 45 per cent between 1988 and 1997. The drop in emissions was partly the result of a fall in economic activity and electricity production in the early 1990s. Other reasons were more important. One reason was the restructuring of the power industry, during which hard budget constraints were introduced and the price of coal was raised. Another reason for the fall in emissions was the reorganisation and stricter enforcement of environmental protection. Together, these reforms created strong incentives for power plants to switch to high-quality coal with lower sulphur and ash content. Because of higher coal prices and the introduction of hard budget constraints, power plants improved their generation efficiency, which also contributed to the reduction of emissions. After 1994, the decline in SO2 emissions has continued thanks to the installation of pollution abatment equipment. The final article (Article VI) analyses the conversion of small boilers for heat production from fossil to biomass fuels. It compares the results of six boiler conversion projects in the Baltic states with seven projects in Russia and the Czech Republic. The results show that the conversions in the Baltic states reduced the fuel cost of heat production and achieved cost-effective reductions of SO2 and carbon dioxide (CO2). It also resulted in transfer of technology and know-how, less dependence on imported fuels and the creation of local markets for biofuels.
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| 3. |
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| 4. |
- Börjesson, Pål, et al.
(författare)
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Biomass Transportation
- 1996
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Ingår i: Renewable Energy. - : Elsevier BV. - 0960-1481. ; 9:1-4, s. 1033-1036, s. 1033-1036
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Tidskriftsartikel (refereegranskat)abstract
- Extensive utilisation of logging residues, straw, and energy crops will lead to short transportation distances and thus low transportation costs. The average distance of transportation of biomass to a large-scale conversion plant, suitable for electricity or methanol production using 300 000 dry tonne biomass yearly, will be about 30 km in Sweden, if the conversion plant is located at the centre of the biomass production area. The estimated Swedish biomass potential of 430 PJ/yr is based on production conditions around 2015, assuming that 30% of the available arable land is used for energy crop production. With present production conditions, resulting in a biomass potential of 220 PJ/yr, the transportation distance is about 42 km. The cost of transporting biomass 30-42 km will be equivalent to 20-25% of the total biomass cost. The total energy efficiency of biomass production and transportation will be 95-97%, where the energy losses from transportation are about 20%. Biomass transportation will contribute less than 10% to the total NOx, CO, and HC emissions from biomass production, transportation, and conversion.
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| 5. |
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| 6. |
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| 7. |
- Börjesson, Pål, et al.
(författare)
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Future Production and Utilisation of Biomass in Sweden: Potentials and CO2 Mitigation
- 1997
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Ingår i: Biomass & Bioenergy. - 1873-2909 .- 0961-9534. ; 13:6, s. 399-412
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Tidskriftsartikel (refereegranskat)abstract
- Swedish biomass production potential could be increased significantly if new production methods, such as optimised fertilisation, were to be used. Optimised fertilisation on 25% of Swedish forest land and the use of stem wood could almost double the biomass potential from forestry compared with no fertilisation, as both logging residues and large quantities of excess stem wood not needed for industrial purposes could be used for energy purposes. Together with energy crops and straw from agriculture, the total Swedish biomass potential would be about 230 TWh/yr or half the current Swedish energy supply if the demand for stem wood for building and industrial purposes were the same as today. The new production methods are assumed not to cause any significant negative impact on the local environment. The cost of utilising stem wood produced with optimised fertilisation for energy purposes has not been analysed and needs further investigation. Besides replacing fossil fuels and, thus, reducing current Swedish CO2 emissions by about 65%, this amount of biomass is enough to produce electricity equivalent to 20% of current power production. Biomass-based electricity is produced preferably through co-generation using district heating systems in densely populated regions, and pulp industries in forest regions. Alcohols for transportation and stand-alone power production are preferably produced in less densely populated regions with excess biomass. A high intensity in biomass production would reduce biomass transportation demands. There are uncertainties regarding the future demand for stem wood for building and industrial purposes, the amount of arable land available for energy crop production and future yields. These factors will influence Swedish biomass potential and earlier estimates of the potential vary from 15 to 125 TWh/yr.
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| 8. |
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| 9. |
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| 10. |
- Börjesson, Pål
(författare)
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Biomass in a Sustainable Energy System
- 1998
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The increased use of biomass for energy is as a key strategy in reducing carbon dioxide (CO2) emission, which represents the largest anthropogenic contribution to the greenhouse effect. In this thesis, aspects of an increase in the utilisation of biomass in the Swedish energy system are treated. Modern bioenergy systems should be based on high energy and land-use efficiency since biomass resources and productive land are limited. The energy input, including transportation, per unit biomass produced is about 4-5% for logging residues, straw and short-rotation forest (Salix). Salix has the highest net energy yield per hectare among the various energy crops cultivated in Sweden (Article I). The CO2 emissions from the production and transportation of logging residues, straw and Salix, are equivalent to 2-3% of those from a complete fuel-cycle for coal (Article II). Substituting biomass for fossil fuels in electricity and heat production is, in general, less costly and leads to a greater CO2 reduction per unit biomass than substituting biomass-derived transportation fuels for petrol or diesel. Transportation fuels produced from cellulosic biomass provide larger and less expensive CO2-emission reductions than transportation fuels from annual crops (Article III). Biomass has the potential to become the dominating energy source in Sweden. The current use of about 80 TWh/yr could increase to about 200 TWh/yr, taking into account estimated production conditions around 2015. Swedish CO2 emissions could be reduced by about 50% from the present level if fossil fuels are replaced and the energy demand is unchanged (Articles III and IV). There is a good balance between potential regional production and utilisation of biomass in Sweden. Future biomass transportation distances need not be longer than, on average, about 40 km. About 22 TWh electricity could be produced annually from biomass in large district heating systems by cogeneration (Article IV). Cultivation of Salix and energy grass could be utilised to reduce the negative environmental impact of current agricultural practices, such as the emission of greenhouse gases, nutrient leaching, decreased soil fertility and erosion, and for the treatment of municipal waste water and sludge, leading to increased recirculation of nutrients (Article V). About 20 TWh biomass could theoretically be produced per year at an average cost of less than 50% of current production cost, if the economic value of these local environmental benefits is included (Article VI).
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| 11. |
- Eriksson, E., et al.
(författare)
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Life cycle assessment of the road transport sector
- 1996
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Ingår i: Science of the Total Environment. - : Elsevier BV. - 0048-9697 .- 1879-1026. ; 189-190, s. 69-76
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Tidskriftsartikel (refereegranskat)abstract
- The road transport sector has been studied with a life-cycle perspective. Transport activities and products used for road transportation have been analysed in order to identify those with significant contribution to the total environmental impact. Detailed data on the environmental burdens caused by different transportation activities such as fuel production, fuel combustion at driving, maintenance of the vehicle and production and after use treatment of the vehicle have been collected and transformed into a form usable in life cycle assessment (LCA). A comprehensive and flexible system model for description of road transportation systems has been developed. A software program, KRABAT, has been developed from the system model. The program has been used for calculation of the environmental burdens of road transportation. The use of non-renewable energy is sometimes used as an indicator of the environmental impact of activities. In this study the consumption of non-renewable fuels, electricity and air emissions have been considered. The production, maintenance and after use treatment of the vehicle have shown to contribute significantly to the total environmental impact of road transportation, measured per vehicle kilometer. This is especially valid for passenger cars, for which the amount of fossile fuel used for production of the vehicle is about 10% of the total amount used during the whole life time of the car. This share is generally much smaller for trucks, since they are used more frequently than passenger cars. The treatment of the different materials of the car after use is of importance for the possibilities of minimization of the environmental impact from road transport. In a case study, the environmental burdens from all processes and transports in the life cycle of newspapers have been analysed. Two after use treatment scenarios were studied, one with 70% recycling and the other with 100% incineration with heat recovery. The total contribution of environmental burdens from transportation to the total of the whole life cycle were studied. It could not be concluded that transportation increased with a higher degree of recycling. This holds true for our assumptions. The result may however be different for other geographical conditions, population densities, etc.
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| 12. |
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| 13. |
- Johansson, Bengt
(författare)
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Renewable Energy in Energy-Efficient, Low-Pollution Systems
- 1997
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Energy use accounts for the dominating fraction of total sulphur dioxide (SO2), nitrogen oxide (NOx), volatile organic compounds (VOCs) and carbon dioxide (CO2) emissions. In this thesis, different strategies for reducing these emissions are evaluated, using a bottom-up approach. The thesis is divided in two parts. Part I (two articles) deals with how energy efficiency improvements and the increased use of renewable energy sources together can contribute to the reduction of emissions from energy use. Part II (four articles) focuses on energy from biomass as a potential option to reduce net CO2 emissions from energy systems. CO2 emissions from electricity and heat production in western Scania, Sweden, can be reduced by 25% and the emissions of acidifying gases (SO2 and NOx) by 50% by the year 2010, compared with 1988 levels, using energy systems based on efficient end-use technologies, cogeneration of heat and electricity, renewable energy sources and low-pollution energy conversion technologies (Article I). Exhaust-pipe NOx emissions from the Swedish transportation sector can be reduced by 50 percent by the year 2015, compared with 1991, by implementing the best available vehicle technologies (Article II). Exhaust-pipe emissions of CO2 can be stabilized at the 1991 level. With further technical development and the use of fuels from renewable sources of energy, NOx emissions can be reduced by 75 percent and CO2 emissions by 80 percent compared with 1991 levels. Swedish biomass resources are large, and, assuming production conditions around 2015, about 200 TWh/yr could be utilised for energy (Articles III-VI). Major reductions in CO2 emissions could be achieved by substituting biomass for fossil fuels in heat, electricity and transportation fuel production (Articles IV and VI). The cost of CO2 reduction would be about US$50-150/tonne C when replacing fossil fuels used for heat production, US$50-175/tonne C when substituting fossil fuels used for electricity production, and US$180-340/tonne C when substituting fossil transportation fuels with biomass (Articles IV and V). Transportation fuels produced from cellulosic biomass are likely to be less expensive than transportation fuels from conventional biomass feedstocks such as oil plants, sugar-beet and cereals.
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| 14. |
- Kågeson, Per
(författare)
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Growth versus the Environment - Is There a Trade-off?
- 1997
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- This book shows that the intensity of use of energy and materials in OECD countries is diminishing over time despite falling metal and energy prices. Material demand is sometimes falling in absolute terms, but there are also a few examples of rapid growth. The supply of fossil fuels and minerals is being exhausted, in some cases at a rapid speed, but the question addressed here is whether the rate of depletion is so fast that there will not be time for technical progress to create adequate substitutes. Overall, this appears not to be the case. The two main industrial metals are very abundant, and most minor metals already have substitutes for many of their applications. A few metals can be expected to become very scarce, but much of the large quantities of them currently in the technosphere could be recycled. Developments in OECD Europe over the last 25 years have resulted in relative or absolute delinking between economic growth and environmental damage. On the other hand, it is uncertain whether continuing economic development along these lines will in all cases lead to the achievement of sustainable development, even whithin 25-30 years. Indeed, this study identifies some examples where slower GDP growth would have resulted in less damage (eg. household waste and emissions of CO2 and NOx, and possibly the depletion of fish stocks and the negative impact of forestry and agriculture on biodiversity).
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| 15. |
- Nilsson, Lars J
(författare)
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Air-handling energy efficiency and design practices
- 1995
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Ingår i: Energy and Buildings. - 1872-6178. ; 22:1, s. 1-13
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- With good design practices and life-cycle cost optimization, the specific fan power for individual (SFPI) fans will be between 0.5 and 1 kW m−3−1. Data from nearly 1000 audited fans in Sweden show that the average measured SFPI weighted by drawn motor power is 1.5 kW m−3 s−1 and the situation appears to be similar in other countries. Contract forms used by Swedish builders and consultants' design practices are analyzed here to search for an explanation of the low performance of installed systems. Identified as two major barriers to efficient system design are the lack of performance specifications when procuring systems and the incentive structure in the building sector. As a consequence, duct design methods, rules of thumb, and vendor recommendations do not lead to system optimization. The broad minima in life-cycle costs over a range of air-handling unit sizes show that potential economic welfare losses from efficiency standards are likely to be smaller than the losses that result from today's design practices.
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| 16. |
- Andersson, Maria, 1965-
(författare)
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Cooperation in local electricity markets : modelling of technical measures
- 1997
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- This thesis presents a system analysis for co-operation in local electricity markets including distributors and customers. The purpose of co-operation is to minimise the system cost of local markets by introducing system measures, such as end-use measures and municipal co-generation plants. Co-operation will strengthen the position of local markets in the national as well as future international electricity markets. With end-use measures local markets will achieve flexibility, additional reserve capacity and ability to avoid sudden large costs for peak loads. Biomass-fired cogeneration plants can become of great importance in an international market. In Sweden there is a simultaneous demand for electricity and district heating, many local markets already include district heating systems and there are major forest areas which can contribute with renewable fuel. The system analysis is partly based on the simulation model (INDSIM) and the linear programming model (MODEST). The simulation model has been further developed (STRATO) to include calculation of system costs. Shadow price analysis has been developed in order to study incentives for system measures. Calculation procedures have been developed that describe cooperation between distributor and customer. Six case studies of a selection of real, existing local markets in Sweden are presented. The studies show the potential economical effects of co-operation measured by system costs and shadow prices. Co-operation has been considered between demand- and supply-side, electricity- and district heating systems and also between different time periods. In a typical local market with 90 000 inhabitants, if end use measures are introduced without cooperation the system cost of the distributor will increase by 14 million SEK for a time period of 25 years. If instead end-use measures are introduced in co-operation, together with a biomass-fired cogeneration plant, the system cost of the local market will be reduced by 444 million SEK. Furthermore, the use of biomass in the local market is increased from 36 to 72 % while the use of oil is decreased from 34 to 1%. Another case study of another local market (50 000 inhabitants) shows that end-use measures will reduce the system cost (excluding investment costs) of an industry by 50 % corresponding to 1.3 million SEK for one year. The end-use measures imply reduced power demand during peak load periods in the local market and increased power demand during non- peak load periods.
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| 17. |
- Beiron, Jens
(författare)
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Drifteffektivisering av installationssystem i fastigheter : Förstudie
- 1997
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- It is possible to improve the energy efficiency of HVAC (Heating, Ventilation and Air Conditioning) systems with the help of building energy management systems. Through deeper knowledge of the dynamics of the system the staff is able to choose a more effective management strategy. Statistics from the energy management system will inform about the system behaviour. It is possible to collect and present the statistics needed thanks to the fast development of information technology and the introduction of computer based building management system.A research project will investigate methods for creation of individual models of HVAC systems based on measurement data. Each system will then be simulated for different operating conditions. As a result of the simulation an optimal management strategy can be chosen. Different performance ratios will be used to evaluate the level of energy efficiency. The performance ratios should be defined so that they can be calculated from measurement data.This pilot study presents the background, purpose and method of the project. Some examples will be given to illustrate ineffective use due to a badly chosen management strategy.SammanfattningInstallationssystem kan drifteffektiviseras genom utnyttjande av driftstatistik. Genom att lära känna sin anläggning kan driftteknikern lättare fatta beslut om optimalaste driftstrategi. Med en förbättrad driftstatistik får teknikern många viktiga upplysningar om anläggningens dynamik och beteende. Som konsekvens av den snabba utvecklingen inom informationsteknologin samt införandet av datorstödda styr- och övervakningssystem finns möjligheter till omfattande datainsamling.Ett forskningsprojektet skall undersöka metoder att utifrån insamlad driftstatistik skapa individuella modeller av installationssystem. Modellen skall för varje enskild anläggning senare kunna utnyttjas för att simulera olika driftfall och därmed kunna optimera valet av driftstrategi. Olika nyckeltal kommer att användas för att utvärdera och följa upp effektiviseringsarbetet. Nyckeltalen skall definieras så att de kan beräknas utifrån insamlad driftstatistik.Denna förstudie beskriver bakgrund, syfte och metodval för projektet. Ett par exempel från utförda mätningar visar på typiska fall av energiineffektivitet som konsekvens av felaktigt vald driftstrategi.
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| 21. |
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| 22. |
- Berndes, Göran, 1966, et al.
(författare)
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Biomass for energy, food and materials in an industrial society of 10 billion people
- 1996
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Ingår i: Renewable Energy. ; 9:1-4, s. 926-929
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Tidskriftsartikel (refereegranskat)abstract
- In this paper we analyse the requirements of bioproductive land in a future industrial so-ciety of 10 billion people, with average per capita economic standard comparable to that of the industrialized countries of today. Despite significantly more efficient technology, lowering demand for both energy and material per service delivered, requirement for food and material alone will call for a heavily increased demand for bioproductive land for use in agriculture and silviculture. Large areas of short rotation energy plantations may be biophysically possible, but will clearly compete for available bioproductive land with agriculture and silviculture, as well as with preservation of the world's biodiversity. Therefore, the notion that there exists large areas of surplus or degraded land, which, without coming in conflict with food production and preservation of biodiversity, can be used for large energy plantations has not fully taken into account possible increased de-mand for bioproductive land from global industrialization and raising of the global average economic standard.
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