1,720,964 research outputs found
Impact of wind speed forecast errors on the financial profit of an existing wind park project in Hungary
Get PDFThe target of this master thesis is to establish a model of calculating the economic impact of wind speed forecast and real data differences on a projected wind park in the area of Mosonmagyaróvár in Hungary. The Hungarian law prescribes to producers of REN energy a supply forecast, which has to be sent regularly to the grid operator. Based on the forecasted energy delivery and the real delivery a penalty system is applied which leads to certain losses for the owner of the wind park.Based on forecast data from the Hungarian Meteorological Service a model is established which calculates an energy delivery forecast. The real energy production also needs to be simulated but with the wind speed data from the tower. Based on the differences of forecasted and ?real? energy delivery the respective fine is calculated and introduced into the economic model of the wind park. As economic model the structure of a net present value calculation over the projects life-time is applied. The technical and financial data are from an existing project of Energiepark Bruck an der Leitha. The paper will show that the direct usage of the received forecast data is resulting to a high power prediction error and therefore also a high fine to be paid. The impact of this fine to the economics of the wind park is rather significant. It is therefore proposed to further fine tune the received forecast data locally before establishing a power forecast to the grid operator
Energy audit and option analysis for renewable energy potential at a Hungarian sawmill
Get PDFThe major starting point of any renewable energy-based project is an accurate theoretical assessment of available renewable energy sources and analysis of an economically optimal location. The northeastern part of Hungary is an economically disadvantaged region with a high unemployment rate; for these reasons, it is important to find ways to reduce the region's energy dependence. The Nyírség microregion within this zone was chosen as the focus of this master thesis in order to augment general knowledge and investigate one specific site's ability to generate feasible future investments. This master thesis evaluates the renewable energy potential and examines energy use at a typical industrial site within the Nyírség region. The research identifies and evaluates the renewable options for this site and suggests an implementation plan for reducing conventional energy consumption. At this given site, solar energy utilization presented the most viable option, so a solar energy-based investment is assessed which could work in parallel with the plant's existing heating system. The final step was to provide an economic assessment to determine the financial viability of moving towards renewables. The master thesis concludes that a financial break-even point for the proposed system is already in the range of the end of life span of such installations, where it is questionable whether they are fully paid off at all. With a 50% investment subsidy, the break-even point was calculated to be within 17 years of implementation. This means that currently, funding is not only important for accelerating the implementation speed, but highly necessary for any implementation at all
Utilization of shallow geothermal energy in Slovakia focused on ground source heat pump domestic installations
Get PDFGeological setting of the Slovak Republic is favorable for occurrence of geothermal energy resources, especially low enthalpy geothermal resources (temperature in the range 20°C - 100°C). The total amount of thermal-energy potential of geothermal waters in prospective areas (proven, predicted and probable) represents 5 538 MWt. Up to now, the geothermal water is used only for recreation (swimming pools, spa), agriculture (greenhouses heating, fishery) and district heating. The low-enthalpy aquifers suitable for district heating system are limited and available only in regions with specific geological structure. Nevertheless, shallow geothermal resources up to the depth of 400 m are suitable for heat extraction and utilization virtually everywhere. The most geographically extensive use of geothermal energy in the world and the most individual use is ground source heat pump (GSHP) technology which can access the moderate temperatures just beneath the earth's surface. Energy of surrounding accumulated an immense amount of energy in the air, ground or water and represent energy sources which are almost inexhaustible and absolutely free. The heat pump technology required to extract heat accumulated in the air, earth and water has been known for more than a hundred years. The most common heat pump systems, determined by the kind of cooled and heated medium, are: air-to-water, water -to-water, ground-to-water. Due to the fact that shallow ground temperatures are relatively constant, GSHP can be effectively used almost anywhere. The field of application of GSHP commonly comprises the space and domestic water heating to a wide range of building types and sizes. GSHP are particularly suitable for new buildings as well as for older existing buildings, especially in conjunction with reduction of heat demand. The most significant direct benefits of appropriately designed GSHP systems are the reduced energy requirement and the use of a sustainable energy source. In addition, indirect benefits of GSHP systems include low environmental impact with a significant reduction of emissions of COB2B and other pollutants. Slovakia's geological and hydrogeological conditions are very favorable for the installation of GHP water-to-water and earth-to-water systems. This is due to the high average heat flow (78 mW/mP2) compared to the central European average heat flow - the energy yield is in the range of 50 W/m. So far, the number of heat pump installations does not reflect these conditions. It is estimated that at present only app. 100 units of heat pumps are in operation and Slovak GSHP market is still very flat. Barriers to growth in the geothermal heat pump market in Slovakia can be overcome. By far, the most significant one is the high installation cost of GSHP systems. Well-designed incentives could help to overcome the higher installation cost of a GSHP and reduce the payback time to a period comparable with other available RES heating systems. The breakeven point can typically be accelerated by favorable government and utility energy incentives. The most important market barriers to GSHP implementation in Slovakia are definitely limited public awareness and low familiarity with technology on the part of practitioners. Generally, there are a number of misconceptions and myths about GSHP technology mainly due to the unprogressive approach of the authorities. Wider general education would improve the reputation of GSHP and enable misconceptions to be challenged. The presented case study, installation of GSHP system in historical building represent promotion of shallow geothermal technology and challenge social and public opinion that heat pump utilization is predominately applicable only to new and low-energy buildings. The successful implementation of the proposed GSHP system could provide further evidence of the reliability and practicality of utilizing shallow geothermal energy with GSHP despite complicated regional geology, and the official restrictions placed on reconstruction. In combination with building renovation, the implementation of a GSHP system is also feasible for older buildings. Reduction of specific heat demand and the most up to date high efficiency GSHP permits the application of GSHP in bivalent mode with an additional energy source even in historical buildings. This argument is supported by the numerous heat pump installations completed in existing older houses and historical buildings
Utilization of shallow geothermal energy in Kosovo focusing on ground source heat pump domestic installation
Get PDFThe territory of Kosovo has a low potential of geothermal energy resource, including high enthalpy and intermediate enthalpy, but some areas as the Municipality of Peja have a low potential enthalpy of geothermal resource with temperature range of 50-100C. There are many places in Kosovo which are easy to found with the temperature range of 20- 70C, but up to now the geothermal energy has been used only for recreation and healing purposes (Report on The State of Water, 2015). During the last 5 years, Kosovos government has made small investment for prefeasibility and feasibility studies about some regions related to opportunities of using geothermal energy with low enthalpy, but until today there has not been any published results. This kind of investigations are made in order to find the possibility of building district heating for small municipalities or areas, but in order to build the district heating, some barriers are encountered because Kosovo has laws on Public Private Partnership (PPP) but unfortunately are not very functional. High potential of development for using low enthalpy geothermal energy comes from private sector by using ground/water or water/water systems in their own homes or companies but actually there is not any support scheme from government for private sector investments. The heat pump market is growing very fast, not only in Kosovo or region but all over EU countries. The efficency of heat pump is much higher compared to previous years because of inverter technology and also the price of heat pumps has dropped compared to 10 years ago. Additionally, the market is growing for air/water heat pump but the same does not apply for ground/water or water/water. In the center region of Kosovo, there are lots of possibilities to use water/water system with a low investment because the ground water is only 1.5 m under the Earths surface. The implementation of project with renewable energy depends on the heat loss of building; the buildings must have a good insulation and windows with doors must have the lowest coefficient of transmission. If the heat loss of buildings is more than 80 W/m2, the investment is not profitable. The heat pump used as a source ground, water and air. The first highest efficiency heat pump is the type of water/water system because the source has constant and high temperature. The second is ground/water system where the temperature is constant but is lower. The third is air/water system where the temperature variation is between -25C to 40C and the source is variable. Based on the respond test, it has been concluded that in location of Prishtina/Hajvali, in the depth of 130 m with borehole heat exchanger with type double U - the average value of heat flux is around 45 W/m. For more information, in Kosovo there are more than 300 units of heat pumps with range from 8 kW up to 3 MW. In contrast, more than 1000 pcs with unit of heat pump by using air as a source have been installed. Heat pump that uses water as a source has very low number of installations because of low water quanitity. Taking into consideration that Kosovo is not able to have network access for natural gas, there is small possibility to use other sources. An important fact is that society in Kosovo has various information and is familiar with heat pumps as a part of renewable energy. They are highly interested to save money in their investment thereby choosing to invest in renewable energy for their homes or companies. However, there are many barriers for making big investments in renewable energy since Kosovos government is working so slow in the field of using it. On the other hand, it is worth mentioning that there are some grants from EBARDEuropean Bank which reduces 15% from the total value of investment, if investor takes a loan in bank for installation of renewable energy for its home or business
A coupled impact of different management and soil moisture on yield of winter wheat (Triticum aestivum L.) in dry conditions at locality Mezőföld, Hungary
No full textVariable rate technology (VRT) in nutrient management has been developed in order to apply crop inputs according to the required amount of fertilizers. Meteorological conditions rarely differ within one field; however, differences in soil conditions responding to precipitation or evaporation results within field variations. These variations in soil properties such as moisture content, evapotranspiration ability, etc. requires site-specific treatments for the produced crops. There is an ongoing debate among experts on how to define management zones as well as how to define the required amount of fertilizers for phosphorus and nitrogen replenishment for winter wheat (Triticum aestivum L.) production. For management zone delineation, vegetation based or soil based data collection is applied, where various sensor technology or remote sensing is in help for the farmers. The objective of the study reported in this paper was to investigate the effect of soil moisture data derived from Sentinel-2 satellite images moisture index and variable rate phosphorus and nitrogen fertilizer by means of variable rate application (VRA) in winter wheat in Mezőföld, Hungary. Satellite based moisture index variance at the time of sowing has been derived, calculated and later used for data comparison. Data for selected points showed strong correlation (R2 = 0.8056; n = 6) between moisture index and yield, however generally for the whole field correlation does not appear. Vegetation monitoring has been carried out by means of NDVI data calculation. On the field level, as indicated earlier neither moisture index values at sowing nor vegetation index data was sufficient to determine yield. Winter wheat production based on VRA treatment resulted significant increase in harvested crop: 5.07 t/h in 2013 compared to 8.9 t/ha in 2018. Uniformly managed (control) areas provided similar yield as VRA treated areas (8.82 and 8.9 t/ha, respectively); however, the input fertilizer was reduced by 108 kg/ha N and increased by 37 kg/ha P
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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