Nóra Hegedűsné Baranyai

Energiabefektetés-energiahozam arány: a megújuló és fosszilis energiaforrások hatékonyságának és fenntarthatóságának összehasonlítása • Energy Return on Investment: A Comparison of the Efficiency and Sustainability of Renewable Sources of Energy and Fossil Fuels

In Hungary, there is a lack of information on the pig production technologies in place in the base year of 2005 and changes since then, as well as a lack of information on the number of pigs kept in different age and production categories, which makes it difficult to calculate ammonia emissions and reductions in the national inventories. Our research team conducted a representative survey of pig farms to assess housing and manure management technologies in the Hungarian pig sector in 2005 and 2015. Novel expert-based calculation methods were developed to convert farm data on pig populations into daily average numbers (DAN) of animals in different statistical categories and feeding phases. The survey resulted in a representative database of housing, manure handling, storage and manure application practices in Hungarian pig production. The data and methodology from the survey helped to develop an ammonia emission calculator and knowledge transfer tool (AGEM-S) for use by farmers.

The increasing global penetration of photovoltaic (PV) technology creates not only enormous opportunities for clean energy production but also poses challenges that put energy systems to the test. Although there are many ways of dealing with the rising share of PV energy, most of these solutions require substantial funding, time, and effort to implement, which highlights the importance of solving some of the issues at their source, i.e., through the direct use of the electricity generated at PV power plants, many of which are owned and operated by households. In recent decades, PV technology has experienced an unprecedented growth in Europe due to a range of reasons, including the nations’ policies and supporting schemes. The goal of the present research was to determine the annual consumption of electricity per capita in the households of certain European countries and how much of this can be covered by the direct use of PV energy in the case of an on-grid PV system and to show what the annual potential of the direct use of PV energy is compared to the annual energy production of the PV systems. The significance and novelty of this research is justified by the lack of comparative scientific studies related to the annual potential of the direct household use of PV energy, which could alleviate some of the problems facing electricity networks with high shares of PV energy. The novel practical benefit of the study was determining, for the examined European countries, the extent to which direct household PV energy use could lower annual electricity consumption from the grid, in the case of on-grid PV systems of different capacities. In addition, these findings also provide information related to the grid’s macro-energy systems in terms of local network load effects related to given investment sizes.

In the context of the ever-growing demand for energy, especially electric energy, from renewable sources, there has been great interest in photovoltaic energy generation. The speed at which the penetration of photovoltaic technology can grow, however, does not simply depend on supply and demand but also on the various policies and schemes adopted by countries around the world. These, in turn, play decisive roles in investment decisions and determine how projects are approached. Investors in photovoltaic (PV) systems need to be aware of the country-specific risk factors for investments and the regulatory environment. The aim of this research was to explore which managerial, economic and technical aspects should be considered in a causal approach when designing PV power plants with over 50 kW of capacity in the Hungarian regulatory environment for the success of the project. The innovative significance of the study is that it presents a validated, practically usable model for the realization of PV power plant projects in Hungary, which provides an in-depth description of the causal steps of their planning and establishment, based on real-life experience. The novel, practical benefit of the research is that it updates and clarifies the steps necessary for the design of PV power plants, since nowadays there are no current scientific works that provide knowledge of a sufficient depth regarding such projects, so these characteristics need to be investigated.

Despite the rapid spread of the use of wind energy to generate electricity, harnessing this energy source remains a great challenge due to its stochastic nature. One way of dealing with this is to prepare accurate wind power forecasts. This paper explored the accuracy of day-ahead and intraday scheduling of energy generation of the onshore and offshore wind farms of the member countries of the European Network of Transmission System Operators (ENTSO-E) in the period from 2013 to 2021. The precision of the scheduling activities showed a varying picture: the onshore wind farms of Germany, Spain, France, and Sweden produced more precise forecasts than others, with annual downward and upward regulatory needs between 0.8% and 14.4%, and from 0.8% to 6.5%, of the yearly energy generation, respectively. In certain countries, however, the forecasts were less accurate, with discrepancies exceeding 41% for downward and 132% for upward regulation. As for offshore wind farms, the annual downward and upward regulatory needs ranged between 0.9% and 61.7%, and from 1.3% to 44.1%, respectively, with Germany and Denmark producing the most accurate schedules. The innovative novelty and practical contributions of this study are that it determines and presents information related to the accuracy of the day-ahead and intraday wind power generation forecasting of the ENTSO-E countries, which is of practical relevance to the transmission system operators (TSOs), the main actors in the energy market and the decision-makers, too. This information may also help investors who invest in onshore and offshore wind farms with the economic aspects, and it may also greatly contribute to the market-related development of the management systems of energy storage solutions related to these technologies.