Tag Archives: energy

261-268 M. Rajaniemi, M. Turunen and J. Ahokas
Direct energy consumption and saving possibilities in milk production
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Direct energy consumption and saving possibilities in milk production

M. Rajaniemi, M. Turunen and J. Ahokas*

University of Helsinki, Faculty of Agriculture and Forestry, Department of Agricultural Sciences, PL 28 (Koetilantie 5), 00014 Helsingin yliopisto, Finland; *Correspondence: jukka.ahokas@helsinki.fi

Abstract:

Direct energy consumption in milk production varies largely because of machinery, production systems, working habits and maintenance. There are good possibilities to save energy in milk production. The magnitude of energy savings are in the order of tens of percent, which means that energy saving potential is quite high. Energy saving can be achieved with efficient system and machinery choices. Also adjustments and maintenance have an effect on energy consumption. To save energy the farmers should have means to measure energy and follow energy consumption. There should also be more information of energy saving possibilities and machinery energy consumptions.

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237-244 M. Zajicek, and P. Kic
Heating of large agricultural and industrial buildings
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Heating of large agricultural and industrial buildings

M. Zajicek¹,* and P. Kic²

¹Institute of Information Theory and Automation, The Academy of Science of The Czech Republic, v.v.i.; *Correspondence: zajicek@utia.cas.cz 2Czech University of Life Sciences Prague, Faculty of Engineering, Czech Republic

Abstract:

This paper presents the results of the simulation calculations used in the selection and design of an appropriate method of heating of large buildings for agricultural or industrial purposes. These halls are characterized by a large built-up area, large room height and high consumption of energy for heating. The aim of the simulation calculation was to find a way of heating, which leads to a reduction in energy consumption while maintaining the required thermal comfort of indoor environment. The calculations were performed using the CFD software ANSYS-Fluent. For comparison of variants, a 3D model was used, including a heat source, natural convection and heat transfer through surrounding structures. The results of the thermal comfort of the working environment in the level of people or the growing zone of plants or the storage space for goods were mainly studied. The second area of interior space, especially important in terms of heat losses, is the level of the ceiling. The results of the calculations provide a detailed analysis of the vertical temperature profiles and the effect of the surrounding walls surface temperature on the thermal state of an indoor environment. The created model was verified according to the results of experiments in large buildings equipped with different heating systems. Based on the results of the simulation calculations and according to the results of experimental measurements, radiant heating method seems to be the suitable heating system solution for studied types of buildings.

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603-610 J. Ružbarský, M. Müller and P. Hrabe
Analysis of physical and mechanical properties and of gross calorific value of Jatropha curcas seeds and waste from pressing process
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Analysis of physical and mechanical properties and of gross calorific value of Jatropha curcas seeds and waste from pressing process

J. Ružbarský¹*, M. Müller² and P. Hrabe²

¹Technical University of Košice, Faculty of Manufacturing Technologies, Department of Technological Systems Operation, Štúrova 31, Prešov 08001, Slovak Republic;
*Correspondence: juraj.ruzbarsky@tuke.sk
²Department of Material Science and Manufacturing Technology, Faculty of Engineering, Czech University of Life Science, Kamýcká 129, 16521 Prague, Czech Republic

Abstract:

The  research  was  performed  with  an  aim  to  investigate  physical  and  mechanical properties and a gross calorific value of Jatropha curcas seeds and particular products (waste) of  a  pressing  process.  Sizes  of  seeds,  an  energy  which  is  necessary  for  pressing  an  oil  and  a setting  of  the  gross  calorific  value  were  tested  parameters.  Tests  were  performed  at  Jatropha Curcas seeds of a brown colour (that means gnaw). The pressing process waste amounts up to 80%. The proportion of the kernel mass to the coat mass is 1:0.62. From the research results it follows that the coat mass is 37.60%. The seed coat belongs among interesting material owing to  the  gross  calorific  value.  For pressing  the  whole  seeds  it  is  necessary  of  about  30%  higher energy than for pressing the kernels of Jatropha curcas.

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319-328 S. Kalinauskaitė,, A. Sakalauskas, E. Šarauskis, A. Jasinskasand M. Ahlhaus
Relation of energy content variations of straw to the fraction size, humidity, composition and environmental impact
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Relation of energy content variations of straw to the fraction size, humidity, composition and environmental impact

S. Kalinauskaitė¹,*, A. Sakalauskas¹, E. Šarauskis¹, A. Jasinskas¹and M. Ahlhaus²

¹Aleksandras Stulginskis University, Studentų g. 11, Akademija, Kauno r.LT-53361, Lithuania; *Correspondence: solveiga.kalinauskaite@gmail.com
²Fachhochschule Stralsund, Institut für Regenerative Energie Systeme (IRES),Zur Schwedenschanze 15, 18435 Stralsund, Germany

Abstract:

Biomass is the major source of renewable energy, the use of which is very importantin energy, environment and economical aspects. Biomass enables the replacement of fossilfuels, the importance of biomass usage is related to global warming questions. Biomassmoisture content is one of the main factors affecting straw preparation for the usage cost.In this research the main focus is on straw and different biomass composition and how itinfluences the solid biofuels preparation for usage, paying attention to straw fraction, humidity,composition and finally how it influences the energy and environmental aspects. Testedsamples consist of different composition- raw straw, 100% yellow straw pellets, 100% greystraw pellets, 98% straw pellets with 2% additives, 50% straw and 50% hay pellets, 49% strawand 49% hay pellets with 2% additives, 100% hay pellets, 98% hay pellets with 2% additivesand additionally two samples of straw briquettes with different chop size – (20 mm) and(30 mm and 10 mm). This research pays attention to the main material characteristics –moisture value, ash content, HHV (higher heating value), pyrolysis coke. Research results willhelp to find the best biomass pellet and briquette composition for solid biofuel usage. Duringthe research it was found that the lowest moisture value was 98% hay pellets with 2% CaOadditive – 5.79%. Highest amount of ash value was found in 50% straw and 50% haycomposition pellets – 0.021 g. Highest amount of HHV were tested pellets which consisted of98% hay with 2% CaO additives. Highest amount of pyrolysis coke in organic and dry matterwere in 100% yellow straw tested samples.Achieved results will help to estimate material fraction, humidity and composition on biomasspreparation for conversion steps, following biomass usage energy and environmentrequirements. These research results will help to realise further tasks of agricultural biomassusage in practice.

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523-527 J. Ahokas,, H. Mikkola, T. Jokiniemi, M. Rajaniemi, W. SchäferH. Rossner, V. Poikalainen, J. Praks, I. Veermäe, J. Frorip and E. Kokin
ENPOS – Energy positive farm
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ENPOS – Energy positive farm

J. Ahokas¹,*, H. Mikkola¹, T. Jokiniemi¹, M. Rajaniemi¹, W. Schäfer²H. Rossner³, V. Poikalainen⁴, J. Praks⁴, I. Veermäe⁴, J. Frorip⁵ and E. Kokin⁵

¹University of Helsinki Department of Agricultural Sciences, PL 28(Koetilantie 5), 00014 Helsingin Yliopisto, Finland;
*Correspondence: jukka.ahokas@helsinki.fi
²Agrifood Research Finland MTT, MTT, Kotieläintuotannon tutkimus,Jokioinen Vakolantie 55, 03400 Vihti, Finland
³Estonian University of Life Sciences, Institute of Agricultural andEnvironmental Sciences, Kreutzwaldi 1, Tartu EE51014, Estonia
⁴Estonian University of Life Sciences, Institute of Veterinary Medicine andAnimal Sciences, Kreutzwaldi 62, EE51014 Tartu, Estonia
⁵Estonian University of Life Sciences, Institute of Technology, Kreutzwaldi 56,EE51014 Tartu, Estonia

Abstract:

In ENPOS (Energy Positive Farm) project possibilities to save energy on Estoni anand Finnish farms was studied. Energy can be saved easily and without large financial costs10 –30%. The most important thing is to increase the energy knowledge of the farmers. Thismeans advisory work and energy education.Energy bookkeeping and energy analysis are important things in energy consumption follow-up. The farm energy consumption should be followed and with this acquired knowledge farmerscan notice where they consume more energy than on average and also where they are betterthan others.Energy consumption is not easy to follow because this would mean in most cases energy meterassemblies and this is costly. New agricultural machinery could be designed so that they includeenergy consumptions meters.

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307-318 A. Jasinskas,, R. Simonavičiūtė, E. Šarauskis, A. Sakalauskasand S. Čekanauskas
Assessment of unconventional bioenergy plant chopping, milling and pelleting quality indicators and physical-mechanical properties
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Assessment of unconventional bioenergy plant chopping, milling and pelleting quality indicators and physical-mechanical properties

A. Jasinskas¹,*, R. Simonavičiūtė¹, E. Šarauskis¹, A. Sakalauskas¹and S. Čekanauskas²

¹Aleksandras Stulginskis University, Faculty of Agricultural Engineering,Institute of Agricultural Engineering and Safety, Kaunas-Akademija,Studentu str. 15A, LT-53361 Kauno r., Lithuania;
*Correspondence: algirdas.jasinskas@asu.lt
²Aleksandras Stulginskis University, Experimental Station, Kaunas-Akademija,LT-53361 Kauno r., Lithuania

Abstract:

This paper provides the research results of techniques for solid biofuel preparation,while usage of chopping (chipping), milling and pressing (pelleting) of the unconventionalbioenergy plants – elephant grass (Miscanthus x giganteus), fibrous hemp (Futura 75) andfibrous nettle. These energy plants were grown in the experimental fields of the Institute ofAgriculture, Aleksandras Stulginskis University and Lithuanian Research Centre forAgriculture and Forestry. It was approved as the methodology for solid biofuel preparation ofunconventional bioenergy plants, and was selected as the technique for plant chopping, milling,pressing, and the technique for determination of plant chaff, mill and pellet quality. There arepresented results of the experimental research. There were determined the unconventionalbioenergy plant stems, chaff and mill chopping quality, in justification of the use of the drumchopping and hummer milling equipment for prepared chaff and mill fractional composition.The quality of stem chaff and mill fineness was defined according to the most widely usedmethodology approved by the EU countries. There were determined physical-mechanicalproperties of these unconventional bioenergy plant chaff, mill and pellets – plant moisturecontent, bulk density, natural slope and failure angles. Key words: elephant grass, hemp, nettle, stems, chaff, mill, pellets, moisture content, bulkdensity, fractional composition.INTRODUCTION

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39-48 J. Frorip, E. Kokin, J. Praks, V. Poikalainen, A. Ruus, I. Veermäe, L.Lepasalu, W. Schäfer, H. Mikkola, J. Ahokas
Energy consumption in animal production – case farm study
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Energy consumption in animal production – case farm study

J. Frorip¹, E. Kokin¹, J. Praks¹, V. Poikalainen¹, A. Ruus¹, I. Veermäe¹, L.Lepasalu¹, W. Schäfer², H. Mikkola³, J. Ahokas³

¹Estonian University of Life Sciences, Kreutzwaldi 1, EE51014, Tartu, Estonia;
e-mail: juri@monte.ee
²MTT Agrifood Research Finland, Agricultural Engineering Research
(MTT/VAKOLA), Vakolantie 55, FI-03400 Vihti, Uusimaa, Finland;
e-mail: winfried.schafer@mtt.fi
³Department of Agrotechnology, University of Helsinki, P.O. Box 28 (Koetilantie 3),
FI-00014 Helsinki, Finland;
e-mail: Jukka.ahokas@helsinki.fi; hannu.j.mikkola@helsinki.fi

Abstract:

The objective of this study was to analyse the energy use by the dairy case-farm with un-insulated cowsheds in Estonia for the period of 2009-2010. The energy balance calculation includes the direct energy input of fuel, lubricants and electricity and the indirect input of forage, cereals, concentrates for young stock, dairy cattle and buildings. Energy outputs are milk, meat, and manure. The energy values were calculated multiplying the quantities of inputs and outputs by their energy conversion factors. The quantitative parameters of the inputs and outputs are based on book-keeping data, the energy conversion factors of feed were measured. The energy output-input ratio of the case-farm was 1.88 in 2009 and 1.85 in 2010. Energy input of milk was 5.4 and 5.3 per MJ kg-1, respectively. Our study indicated that the case farm energy consumption is generally higher than that of comparable European dairy farms. The further research is needed to find the reason of mentioned differences.

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85-95 T. Jokiniemi, H. Mikkola, H. Rossner, L. Talgre, E. Lauringson, M. Hovi and J. Ahokas
Energy savings in plant production
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Energy savings in plant production

T. Jokiniemi¹, H. Mikkola¹, H. Rossner², L. Talgre², E. Lauringson², M. Hovi³ and J. Ahokas¹

¹Department of Agrotechnology, University of Helsinki, P.O. Box 28, 00014 Helsinki,
Finland; e-mail: tapani.jokiniemi@helsinki.fi; hannu.j.mikkola@helsinki.fi;
jukka.ahokas@helsinki.fi
²Institute of Agricultural and Environmental Sciences, Estonian University of Life
Science, Kreutzwaldi 1, EE51014 Tartu, Estonia; e-mail: helis.rossner@emu.ee;
liina.talgre@emu.ee; enn.lauringson@emu.ee
³Institute of Technology, Estonian University of Life Science, Kreutzwaldi 56,
EE51014 Tartu, Estonia; e-mail: mart.hovi@emu.ee

Abstract:

At the moment energy costs in agriculture are relatively low compared to other costs. In 2010 energy costs were 10% of the total agricultural costs in Finland. However, energy costs are expected to grow. The EU has made a directive on Energy End-Use Efficiency and Energy Services, which claims that agriculture must save 9% of their average energy consumption of the period 2001–2005. The highest energy consumptions in plant production originate from agro-chemicals (fertilizers, lime and pesticides). However, regarding energy statistics, energy consumption for agrochemicals is allocated to the industrial sector. Chemicals are for this reason seen as indirect energy in agriculture. Direct energy input in agriculture consists of fuels and electricity. The most dominating direct energy input in plant production is diesel and heating oil. Energy consumption can be easily decreased in plant production by some 10–30%. For instance, 10–20% of energy can be saved in grain drying by heat insulation. In machine operations the dominating factor in energy consumption is the driver. With properly implemented maintenance and adjustment and efficient driving habits, 10–30% savings can be achieved

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141-148 J. Lepa, V. Palge, K. Jürjenson, K. Toom, M. Pennar and A. Annuk
Wind Power in Heat Energy Systems
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Wind Power in Heat Energy Systems

J. Lepa, V. Palge, K. Jürjenson, K. Toom, M. Pennar and A. Annuk

Department of Energy Application, Institute of Technology,
Estonian University of Life Sciences, 56 Kreutzwaldi Str., EE51014 Tartu, Estonia
e-mail: jaan.lepa@emu.ee

Abstract:

The article discusses opportunities for the use of wind power plants in order to supply heat to coastal settlements. The possibilities of meeting the needs of heat consumption in the city of Paldiski in Estonia using general data from wind power output serves as an example in the present paper. Monthly electricity and heat consumption graphs and schedules of the Republic of Estonia together with production charts of wind power plants were used as initial data for the research. The investigation of wind energy production charts shows that, due to stochastic peculiarities of the wind, it is especially complicated to match the latter and the electricity consumption charts. There have even been cases, where the dispatcher has been forced to limit wind energy production maxima so that it would not interfere with the work of generators at large power plants. However, satisfactory correlation was revealed between the monthly graphs of both electricity and heat energy overall annual consumption, and wind power production charts. Nevertheless, there are still high deviations, and therefore, in order to use wind energy for heating purposes, powerful storage devices or additional feeding units are necessary to level the fluctuations of electric power produced by wind plants.
The problems related to the production usage of wind power plants in heat and power engineering are to a certain extent less complicated due to the fact that heating systems can be supplemented with additional heat energy storages. Considering the above mentioned issues, the authors suggest a more extensive usage of wind power plants for heating towns and settlements, particularly in cases when production peaks interfere with the work of power systems.
Due to new capacity installations, the overall production of the wind power plants is constantly increasing. Thus, the authors recommend that the maximum power usage coefficient of an operating wind power plant, not their overall production data should be used for analyzing the efficiency of the present power plants and for designing new ones. This will be more correlated with power and heat consumer load curves.

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165-176 H. Mikkola and J. Ahokas
Energy Management of Future Farms
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Energy Management of Future Farms

H. Mikkola and J. Ahokas

University of Helsinki, Department of Agrotechnology
POB 28, 00014 University of Helsinki; e-mail: Jukka.Ahokas@helsinki.fi

Abstract:

Energy management in agriculture will be of current interest in the near future. Modern agriculture is run by fossil energy and it is unclear how this energy input will be replaced with renewable energy. The year 2008 gave some foretaste how rapidly and how much energy price can rise. Energy saving and exploiting farm’s own energy resources are ways to reduce dependency on oil. Nitrogen fertilizer is the most significant energy input in plant production because ammonia manufacturing is very energy intensive. Crop rotations including legumes, green fertilization, and better manure management are measures to replace synthetic nitrogen. Traditional work chains can be replaced with more energy efficient operations. Direct drilling and grain preservation methods other than drying are good examples. Animal housing requirements for inside temperature and air quality define the demand for heating and ventilation. Along with milking and milk cooling, they are the most significant energy inputs in animal production. Animal welfare has to be respected always; however, by means of heat recovery and biogas production it is possible to save energy and exploit energy from manure. Energy should not be considered as a separate question; on the contrary, a farm has to be considered as a whole and as a part of the rest of the society. Better energy management and plant nutrient recycling are combined issues and require more comprehensive approach than it has been the case.

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