Attila Kerényi

Biogas utilization and its environmental benefits in Hungary

Abstract The aim of our report is to refer on the actual state of small biogas power plants in Hungary summarising the increase in their number and capacity and their effects on climatic change. The above is based on the CO2 emission of the energetic utilization of biogas and the calculation of its ecological footprint that were compared to the environmental effects of natural gas energetic utilization. The aim of this paper does not include the complete life cycle analysis therefore the environmental benefits of the energetic utilization of biogas produced from various raw material are presented via only the direct CO2 emission of the production process.

The environmental and economic aspects of a biogas power plant

In the present study the authors examined the carbon footprint of a biogas power plant in eastern Hungary, and the economic aspects of its operation. About 65% of the raw materials are transported from within a 12 km radius of the surrounding area; however, the remaining 35% arrives from distances greater than 90 km. In 2013 – taking into consideration the complete life cycle of the power plant – the GHG (greenhouse gases) emission linked to each operational phase was 208,173 kg CO₂ equivalent, which is only 6.3% of the emission accompanying the production of the same quantity of energy in the Hungarian energy structure; therefore, from an environmental perspective, the energetic utilization of biogas is quite favorable. It became clear during an investigation into the economic aspects of the power plant’s operation that in the current conditions its operation is on the margins of sustainability. The acquisition of raw materials must be rethought and rationalized. This can be achieved by (1) the replacement of the relatively expensive self-produced feedstock by easily fermentable (bio) waste materials, and (2) the radical reduction of transportation distances. Moreover, it is imperative to find possible ways to utilize the surplus thermal energy and the sale of the fermented manure (biomanure) produced.

Preliminary results on the determination of solar energy potential using LiDAR technology

According to the challenge of the reduction of greenhouse gases, the structure of energy production should be revised and the increase of the ratio of alternative energy sources can be a possible solution. Redistribution of the energy production to the private houses is an alternative of large power stations at least in a partial manner. Especially, the utilization of solar energy represents a real possibility to exploit the natural resources in a sustainable way. In this study we attempted to survey the roofs of the buildings with an automatic method as the potential surfaces of placing solar panels. A LiDAR survey was carried out with 12 points/m2 density as the most up-to-date method of surveys and automatic data collection techniques. Our primary goal was to extract the buildings with special regard to the roofs in a 1 km2 study area, in Debrecen. The 3D point cloud generated by the LiDAR was processed with MicroStation TerraScan software, using semi-automatic algorithms. Slopes, aspects and annual so...

Loess Features on Tokaj Hill

A variety of landforms have developed on the 5–30 m thick loess which mantles Tokaj Hill, a solitary elevation (516 m) of volcanic rock in Northeast-Hungary, on the right bank of the Tisza River. Following a brief history of loess research in Hungary, the chapter presents specifically the findings of investigations into the loess cover at Tokaj. Major erosional features on the loess mantle of Tokaj Hill include sunken lanes, gullies, pipes and subsidence hollows. Based on measurements carried out on a slope with cultivation terraces, the relationships between superficial and subsurface loess erosion are presented in detail. The role of human activities in the removal of the loess mantle is also considerable on the hill, which gave its name to the best-known historical wine-producing area of Hungary.

Utilization of solar energy potential on roofs: building extraction from the LiDAR database in a Hungarian sample area

According to the Horizon 2020 climate and energy package, legislation has to meet the 20-20-20 target. That means that EU member countries have to reduce the amount of greenhouse gases by 20% to increase the proportion of renewable energy to 20% and to improve the energy efficiency by 20%. Our study is connected to renewable energy issues, the goal was to assess the extent of solar radiation exploitation potential of roofs in a typical Hungarian residential area. Our sample area (~1 km 2 ) was in Debrecen, the second largest city in Hungary. An aerial Light Detection and Ranging (LiDAR) survey was conducted with the density of 10 points/m 2 . We extracted the buildings with the MicroStation TerraScan software and tested the geometry of them. The classification and vectorization of buildings were based on Terrascan semi-automatic algorithms in a Microstation environment. Primarily the roofs were important for us as these surfaces are the possible spaces for thermal and photovoltaic equipment. We determined the slope and aspect for each roof element and summarized the whole possible surface using the detected roof parts. Our research shows that the LiDAR

Annual pattern of the coefficient of performance considering several heat pump types and its environmental consequences

Heating with the use of ambient energy by heat pumps is a very effective way to reduce CO2 emission. However, efficiency, economic and environmental advantages depend on the type of the heat pump and the temperature of the source, the latter usually changes during the heating season. The aim of the paper is to give the annual pattern of the COP and emission as a function of the typical source temperature pattern, moreover yearly summarized energetic and emission values are also added in the case of air source, water source and ground source heat pump systems, compared to some conventional heating mode.

Human Impact in a Systems Approach

All the material and energy flows evolved independently from and having existed prior to human presence are considered to be natural in origin. The cycles which are the least influenced by humankind and, therefore, in a ‘quasi-natural’ state are also in a dynamic equilibrium. The general model of material and energy flows is a result of a generalisation to the greatest extent and reflects the most relevant features of the so-called global geochemical cycles. Geographical factors relevant in geomorphologic processes can be recognised and interpreted in this model. Human society, over its history of approximately 10,000 years, has been intervening into natural processes more and more actively and effectively. Society can influence any of the exogenic geomorphic processes and human impacts can be present at any stage of such processes. There is not a single element of the natural system that would not be influenced by human intervention sooner or later. The degree of changes depends on the intensity of human intervention as well as on the susceptibility of the physical system. Anthropogenic activities without a direct impact on geomorphologic processes can also have consequences on the surface. In their investigation, a system-approach analysis can be of help.