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2011 Zöld A., Csoknyai T., Kalmár F., Szalay Zs., Talamon A. Requirements of nearly zero energy demand buildings with renewable energy sources

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Pollack Periodica
Authors: Daniel Buček, Martin Orfánus, Peter Dušička, and Peter Šulek

sources to 20% of total consumption by 2020 [ 3 ]. The dynamic development of the energy market (the emergence of renewable energy sources, in particular hard to predict sources e.g. solar and wind power plants) requires more flexible management of energy

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The paper presents significant aspects regarding the concept and details of constructive solutions used to design and implement an energy efficient school building in Romania. Although the site is in a moderate seismic zone, the structural needs of the building impose specific insulation solutions for making the passive house concept applicable. Renewable energy sources are also applied to optimize the maintenance cost and to reduce the payback period to a feasible level. In order to prove the benefits of the solutions, to justify the higher initial investment, to improve the real-time energy consumption of the building, as well as to keep track of the internal climate parameters, a complex monitoring system was planned and implemented. Details and correlation between specific details and temperature sensors distribution are also presented.

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Production and utilization of renewable energy sources (e.g. biogas) are justified not only by energy-political, but by environmental aspects, too. It can be verified the necessity of the complex ecological aspects by biogas production experiments and its utilization tests in gas engines therefore we created a complex biogas production and utilization system, so that both the energy and the environmental goals can be achieved together. In the interest of an optimal solution it is necessary to analyze the two objective functions (the production and utilization functions) together, considering that the principle of the complex optimization focuses just on the environmental-friendly energy utilization. The centre of this system is the integrated waste-management. Its advantages are the local and global environmental results, energy production independent of external influences, as well as a near optimum solution ecologically.

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Marovölgyi B.: 1998. ”The establishment and utilisation of energy plantations” In: Utilisation of renewable energy sources, Gödöllő Sulyok D. — Megyes A. — Dobos A. — Nagy J.: 2005. ”The possibilities of energetic utilisation of

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st Century: Renewables 2011, Global Status Report. [3]. Hungary's Renewable Energy Utilisation Action Plan on trends in the use of renewable energy sources until

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The Triassic karstic aquifer is the system with the greatest potential for the utilization of thermal waters in Serbia. As an integral part of the Dinaric tectonic unit, the Triassic aquifer extends widely over the western part of the Serbian territory and is characterized by cold waters. In contrast, the same but confined type of aquifer overlain by thick Tertiary sediments in the Pannonian Basin has significant geothermal potential. The major potential for tapping geothermal flow is in the southern and southwestern parts of the Pannonian Basin (Srem) and in the adjacent areas of Mačva and Semberija in the Sava tectonic graben. In these areas the Triassic karstic aquifer has been tapped by several boreholes with depths ranging from 400 m to 2400 m. The temperature of the hottest water exceeds 75 °C, while maximal discharge is 40 l/s.

Although the prospect of wider utilization of geothermal energy undoubtedly exists, some Serbian national plans count on a limited contribution of geothermal energy in renewable energy sources of only 4%. This is probably due to the low level of current utilization, and the inefficient use of even some highly productive wells with a high water temperature, such as those drilled in the most prosperous Mačva region.

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Abstract

A net zero-energy building (NZEB) is considered as a resident or commercial building where the energy needs are covered by using locally available renewable energy sources and technologies. Various types of heat pumps are widely used energy conversion systems for NZEB strategies implementation. This paper is focused on the development of a novel LabView-based model for an air-source heat pump system that absorbs heat from outside air and releases it inside the building as domestic hot water supply or room's space heating by using hot water-filled fan-coils. In the first research steps the mathematical background of the considered heat pump system has been developed. Then the LabView-based software implementation of the air-source heat pump and entire heating circuit model is unfolded and presented. The result is a versatile and powerful graphical software toolkit, suitable to simulate the complex heating, ventilation and air-conditioning processes in net-zero energy buildings and to perform energy balance performance evaluations. Beside the elaborated mathematical models, a concrete software implementation example and measurement data is provided in the paper. Last but not least, the proposed original model offers a feasible solution for future developments and research in NZEB applications modeling and simulation purposes.

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A megújuló energiahordozók közül Magyarországon a biomassza nyújtja az egyik legígéretesebb lehetőséget a fosszilis energiaforrások részleges kiváltására. Jelen tanulmányban az elméleti gazdaságtan, a statisztika és a társadalomtudományok eszköztárával elemezzük a biomassza munkaerőpiacát. A munkaerő-piaci kereslet nem minden esetben egyezik meg a kínálattal. A szűkülő lehetőségek következtében a biomassza népességmegtartó képessége sem érvényesül minden esetben. A magyar piacon szakemberhiány van, így a kvalifikált alkalmazottak naponta ingáznak otthonuk és munkahelyük között. Ennek oka elsősorban abban rejlik, hogy az oktatási rendszer nem képes kellő arányban kinevelni magasan képzett, ökoenergetikai ismeretekkel rendelkező szakembereket. A lokális munkaerőt igénylő szántóföldi munka a képzetlen munkaerő számára jelenthet egyfajta kitörési lehetőséget. A munkaerő-piaci diszkrimináció – amely a kék-, valamint a fehérgalléros alkalmazottakat egyaránt érinti – és az oktatási rendszer hiányosságai egyértelműen a paradigmaváltás szükségességét irányozzák elő. A 2011–2012-es reformok ez idáig nem hoztak számottevő változást az ökoenergetika számára, így kiemelkedően fontos lenne a megújuló energiaforrások hasznosításával foglalkozó szakok arányának növelése. Amennyiben az intézmények átszervezésén kívül nem történik lényegi, gondolkodásmódbeli változás, feltehetően a biomassza-alapú energiatermelés sem fogja elérni a kívánt szintet. A biomasszapiac nem érvényesülhet szárnyaló mezőgazdasági ágazat nélkül.

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