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Global climate and ecological crisis urge to decarbonazation of EU through sustainable low carbon alternatives to achieve carbon neutrality by 2050. Within this context, Power-to-Hydrogen-to-Power (P2H2P) technologies are playing an essential role in the energy transitions boosting the energy system flexibility, facilitating the integration of renewable energy sources and providing a promising pathway for long-term energy storage and clean fuel supply. Driving forces behind this research are the imperative raise t...

The article presents directions for improving diamond drill bits designed for drilling in hard abrasive rocks. The first direction involves the development of multilayer tools in which impregnated diamond layers are separated by soft, non-diamond interlayers of the same configuration. Additionally, ring-shaped bits have been developed with diamond-bearing layers placed on the concave surface of the matrix. This design enables the use of a weakened rock zone beneath the working elements, enhancing rock-breaking eff...

This paper presents the modeling and simulation of an electrical energy management system that integrates a 300 V, 8 Ah lithium-ion battery, a DC shunt machine, and a variable DC load using NEPLAN simulation software. The main purpose of this work is to investigate the performance and control behavior of a hybrid electrical system where the power flow is automatically regulated according to the State of Charge (SOC) of the battery. The DC machine alternates between motor and generator modes depending on the SOC le...

This study presents a multicriteria evaluation for the integration and development of the Limberg Pumped Storage Hydropower Plant (PSHP) in Austria. The research aims to identify the most sustainable and efficient solution to enhance energy storage capacity and operational flexibility within the national energy system. Three development scenarios were analyzed using a Multicriteria Decision Analysis (MCDA) based on the Analytic Network Process (ANP) implemented in Super Decisions (SD) software. Scenario 1 involves...

One of the directions towards a green energy transition is the spread of electric vehicles in the transportation sector. This necessitated the installation of electric charging stations, but as their number increases, so do the problems with their management and the increasing consumption of electricity. In this regard, there is a need to search for intelligent management solutions in the transition to alternative energy sources. This research is related to the development of a project to build a smart system for ...

Complex energy systems, in the current period of transition to a climate-neutral society, comprise two fully functional subsystems, that of fossil fuel-based production and that of production from renewable energy sources. The functional coexistence of these subsystems is achieved due to the capture of the CO2 component from flue gases through the energy vector represented by green H2. This takes on both the role of energy accumulation and the role of transforming the CO2 component, captured during the combustion ...

In the last century human society has registered huge development in all human-related fields, fact that has been possible without doubt by designing technological applications with the usage of diverse natural resources, especially energy ones. Anyway, recorded progress, especially in technological fields, was feasible because of using fossil fuels for electric and thermal energy supply, which resulted besides positive impacts in undesired environmental pollution. Currently most debated effect by CO2 emissions is...

Industrial Control Systems (ICS) are foundational to critical national infrastructure, operating vital processes in sectors such as water treatment, power generation, oil and gas, and manufacturing. As these systems become increasingly integrated with information technology through the Industrial Internet of Things (IIoT), they face growing risks from cyber threats. As Bulgaria accelerates the integration of renewable energy infrastructure, particularly solar, wind, and gas-to-power systems, the cybersecurity of t...

In these article, we discusses the analysis of the profitability of investments in energy storage batteries, in the context of injection policies in the grid in Romania. The study compares the compensation and energy sale regimes for prosumers and producers depending on the installed capacity, thus showing the impact of market prices and tax regulations on the return of investment (ROI). The case study has three scenarios, each with specific formulas for calculating ROI depending on the price of the stored energy ...

All nuclear power plants in Slovakia can effectively prevent emergencies caused by technical or human error. Before commissioning, they must demonstrate to the Nuclear Supervisory Authority that the plant can respond to even extremely unlikely events. The design of the plant has safety systems that will prevent damage to nuclear fuel and the release of radioactive substances so as not to endanger human health and the environment. The maximum design accident for a WWER-440 reactor is a rupture of the main circulati...

Achieving efficient energy systems has become a challenge for researchers, as many engineering applications combine convective heat transfer in fluid saturated porous media, such as nuclear reactors, hydrogen production and storage, underground disposal of waste, food processing and storage, solar power collectors or geothermal systems. For this purpose, it is essential to calculate energy losses and identify methods that involve minimal costs. The paper presents a problem of free convection for a fluid flow throu...

The significant growth of the global population that has happened in the last years strains even more the present fragile balance between the produced and consumed resources, if the current rate of development is to be maintained without change the harmful and the negative effects caused by the global warming will only amplify.The increase of the water level, the desertification of fertile lands and the greenhouse gas effects are only a few of the problems we already need to resolve, because of this the transition...

The transition to renewable energy sources is a key strategy for reducing carbon emissions and ensuring energy sustainability. This study explores the integration of photovoltaic (PV) systems for hydrogen production and storage in Constan?a County, Romania. The region benefits from high solar potential, making it an optimal location for implementing solar energy solutions. The proposed system converts solar energy into electricity through photovoltaic panels, which is then used to power an electrolyzer for hydroge...

As the offshore oil and gas industry faces mounting pressure to reduce its carbon footprint, Floating Production, Storage and Offloading (FPSO) units are emerging as critical platforms for implementing clean energy innovations. This paper explores the potential for integrating renewable energy sources such as offshore wind, solar photovoltaic, and wave energy with advanced energy storage technologies, including lithium-ion batteries and hydrogen-based systems, within FPSO operations. The hybridization of power gen...

The maritime industry represents a significant contributor to global greenhouse gas emissions, primarily through the combustion of fossil fuels used by ship engines. As international regulations tighten and environmental awareness grows, reducing global greenhouse gas emissions from ships has become an important objective. This study explores the potential for emission reduction on passenger ships through the implementation of a hybrid propulsion system. The study methodology involves solving the following aspects...

During the process of adapting renewable energy and ensuring national energy security in the current geopolitical context, technological progress in the field of green energy has received increased attention. This has led to the development of updated policies on investment in onshore renewable energy (which uses wind and solar energy through wind turbines and photovoltaic parks) and offshore renewable energy (which uses tidal, wave, solar, and wind energy through floating photovoltaic parks and wind turbines that...

In this paper, we present some practical considerations regarding the design of power voltage stabilizer equipment. Nowadays, technologies for raising and/or lowering the voltage to a level required by the power line or a consumer are increasingly used (in wind or solar power generation systems, or in energy conversion systems with a direct current intermediate circuit). Our study refers to a conversion solution consisting of two converter stages. The first stage consists of two boost converters operating in antip...

Mannitol is an important raw material in the production of resins, lubricants, coatings, surfactants, explosives, cosmetics and drugs. One of the promising ways to obtain it is the catalytic conversion of inulin, a natural polyfructosan found in large quantities in some agricultural crops. In this study a Ru-containing magnetic catalyst was proposed for the process of hydrolytic hydrogenation of inulin to mannitol. Under optimal reaction conditions a high mannitol selectivity of 44.3 % was obtained 100 % conversio...

Wind power is a source of renewable energy produced by harnessing the kinetic energy of the wind. Wind energy is converted into electricity using wind generators or wind turbines installed in wind farms. It is linked to the kinetic energy of the wind, which is produced when air moves. The energy can be used to create mechanical motion, such as the rotation of the rotors of a wind turbine. To harness wind energy, wind turbines or generators are installed to convert the kinetic energy of the wind into electricity. A...

Georgia's positioning in the context of the European Union's foreign energy policy has become the subject of discussion in the context of the threats coming from the current Russia-Ukraine war. At the same time, determining the effectiveness of the country's energy policy is related to the seventh Sustainable Development Goal - affordable and safe energy. In 2016, Georgia signed the protocol of joining the Energy Community, which determines the conditions for the introduction of EU energy legislation in Georgia in...

The present research explores the integration of a photovoltaic system for an educational building through a comparative analysis using the PVsyst and Simulink platforms. The building, intended for university education, is located in Cluj-Napoca, Romania. Considering the building-s location and specific climate, the feasibility of installing a photovoltaic system was analyzed with the aim of reducing electricity consumption from the electrical grid. The study began with a PVsyst simulation, which indicated that a ...

In light of the pressing need to achieve climate neutrality in the energy sector, the European Union seeks to identify strategies that will enhance and diversify its green energy supplies. As a renewable energy source, green hydrogen promises to offer a viable alternative to fossil fuels where green electricity may be insufficient or inaccessible. This is why the production and supply of this innovative energy carrier is becoming a significant focus in EU politics and research. This article examines and compares p...

Hydrogen-based energy production involves the use of fuel cells or the direct combustion of hydrogen (a particular case being hydrogen combustion in internal combustion engines). Direct hydrogen combustion is still in the testing phase, with challenges arising from its energetic properties, which continue to be a difficult factor. For instance, hydrogen has a low calorific value (about three times lower than methane) in its gaseous phase, which is the phase where combustion occurs, a very high combustion speed (ab...

Biomass is the first form of energy used by man at the same time with the discovery of fire, means all the products of animal and vegetable origin used in present in the production of energy. Actually, the biomass approximately half (44-65 %) of the total renewable energy sources used in the EU, and occupies a third place as a primary energy source in the world, after coal and oil. At the same time represents a sustainable alternative to reduce carbon emissions. The experimental territory is located in the middle ...

Based on the principles of prevention, the employer must seek to eliminate risk at source and, in order of priority, to replace hazards through non-dangers, to separate or isolate areas where there are hazards, ensuring adequate collective and individual protection. However, workers from high and very high voltage power substations continue to be exposed to occupational hazards, suffering accidents at work and occupational diseases with significant repercussions on their health, on colleagues or National Power Sys...

Hybrid electricity storage systems are becoming essential for efficiently managing renewable energy sources and enhancing the stability of power grids. As the adoption of renewables expands, these systems are crucial for balancing supply and demand, mitigating intermittency issues, and ensuring grid reliability. This paper offers an in-depth review of different system configurations used in hybrid storage systems, emphasizing the significance of understanding and optimizing their intricate designs. Recent technolo...

The SWOT analysis of the energy resources of hydrocarbons comes in the context in which the possibility of a black-out is very likely, and the lack of energy resources can cause major damage through enormous financial losses, which through the domino effect can spread economic and national insecurity. In this context, the SWOT analysis energy resources become an essential issue of national security and makes this paper of real interest. The authors consider that the security supply with energy resources of hydroca...

Coverage of Slovakia's energy needs depends primarily on collecting energy from abroad (mostly from the Russian Federation). Therefore, the state is inclined to making substantial use of renewable energy sources, which are also environmentally less aggressive. Slovakia has a significant potential in geothermal energy. The systematic investigation of geothermal energy sources using geothermal wells started in 1971 in Slovakia. There are 120 registered geotherm al wells in Slovakia, which proved about 1787 l.s -1 of...

Experiences from various countries show that without initial state support it is not possible to build basis for applying of t echnologies using renewable energy sources. Presented contribution is orientated to the various mechanisms that are using for support of renewable energy sources. That means st ate regulation in this area generally and basic types of state donation policy in th e frame of European Union and their consequences on the market with renewable energy sources.

Urgent task of energy policy in the near term, in addition to diversification will encourage vigorous national economy, reducing dependence on natural gas and both demand-side measures (in the energy supply of buildings are mainly to improve the thermal protection) by measures on the production, transmi ssion and distribution (increasing efficiency of energy transforma tion and increasing the share of renewable energy at the expense of natural gas).Natural gas can be easily replaced in the supply heat buildings, a...

Some renewable energy sources, such as biomass, hydro, geothermal and tidal energy, produce reliable electricity, which can be distributed to remote locations. Other sources, like solar and wind depend on the weather, but it is predictable and so their usefulness may be suitably amended with permanent renewable energy sources. The vast majority of renewable energy in add ition to their advantages in terms of their source inexhaustibility also has significant drawbacks which significantly limit their expansion. For...

On global scale the nickel coa tings obtaining is realised with electrolytes that have the toxically composition that working at the temperature range 40 - 800C. In this paper was proposed an ecological solution to obtaining the nickel layers and composite coatings with nickel matrix and silicon. The energy consume is reduced be cause the working is passed on ambient temperature. The addition of silicon particles into nickel plating bath leads to significantly changes for the surface morphology and for the roughne...

Here we try to find a compromise way of controlling a continuous variable power system by adopting a hybrid architecture in which the renewable energy sources are coupled with the classic power grid. In such an architecture, a big issue is the control algorithm for management of the energy sources, which had to be designed in such a way that the final consumer remain powered on at all times. We proposed a control algorithm which compares the input and output powers, if the input power is lower than the output, the...

Widespread use of renewable energies is a global priority that must not be ignored. Optimal production and use of renewable energy sources is a necessity. In the current context, characterized by alarming incr ease in pollution caused by energy production from combustion of fossil fuels, is becoming increasingly important to reduce dependency on these fuels. Energy recovery and conservation aim at solutions for a substantial reduction in fuel consumption. In this context we can mention hydrostatic regenerative hyb...

Nor green business, however, designed precisely to reduce the amount of waste that modern society and its technologies generate, is not entirely trouble-free in relation to waste. This problem also applies to photovo ltaic. The issue of life cycle and the final disposal of modules and materials is more or less long a major role for industry. Total amount of photovoltaic waste in Europe is still relatively small and moves around 3800 tons in 2020, this number will grow to 35 000 tones. Sooner or later it will be ne...

Lead-free solutions for protective coatings as an alternative for ecological galvanized steel sheets obtaining were studied in this paper. The lead from zincing baths was eliminated and replaced with bismuth as non hazardous elements. Also other alloying elements (nickel, tin, and aluminium) in zinc melts were added. The making technology of these galvanizing free-lead alloys wa s established in accordance with alloying elements properties. The tec hnological conditions for obtai ning zinc-bismuth coatings with va...

Nowadays, when the amount of exhaustible energy resources in the world are reducing and their prices are increasing proportionately , mankind tries to find alternative sources of energy. Use of solar radiation has huge potential in th e future. Already today, the sunlight is transformed into heat or electric energy. For the conversion of solar energy into electricity we are using photovoltic cells. The Slovak Republic is in the use of photovoltaic systems on the tail in the Euro pean Union. Electricity produced by...

Structure of the mathematical model of underground coal gasification process in terms of material and energy (heat) balance is presented in this paper. Base inputs of gasification process are coal (coal model) and oxidant (a mixture of oxygen and air), which appropriate combination has to ensure the best possible conditions for the gasification process. The expected energy output from coal gasification process is a synthetic gas - syngas. Components such as ash, tar and unburned coal are side outputs of the proces...

The using of low-emission - renewable sour ce of energy (wind, solar and photovoltaic energy, geothermal energy and energy from biomass and biofuels) undoubtedly contributes to the retardation of climate changes. The energy is the essential part for the world function. Today is the achievement of reasonable energy consumption one of the fundamental roles. It has 80% of all greenhouse gas emissions in the world, which are the main cause of the climate change and stronger air pollution. Therefore it is needed to red...

The contribution deals by the suggestion of new manufacturing technology for hand- made screw blade for wind-power plant. A wind turbine is a device that converts kinetic energy from the wind into electricity for distribution. Wind turbine blades are most often fabricated by hand using multiple layers of fi breglass cloth. The traditional method is for the sheets to be cut to shap e, laid down in a mould by hand, sprayed or rolled with resins, and finally cured. The automation of the manufacturing of hand-made pro...

Well organized ventilation systems and air distributions of the school buildings in many countries still appear to be a t opical issue. A lot of various investigations indicated that IAQ problems appear not only because of low ventilation ra tes, but also in cases when the location of exhausted and mainly supply jets is not appropriate. The main motivation is the select of most efficiency air ve ntilation systems and di stribution schemes to improve IAQ for school buildings. The model of university classroom for p...

The work deals with reconstruction of family house on the part of energy for heating need. The essence has been to comparise individual alternatives, which are possible to realise in judge house. In the first part of work is the attention devoted to object describing and to heat loses values before and after the measurements. Than are particularly characterized alternatives of heating, their annual costs for heat production and for amount of fuel, invested costs and the portion of invested and overall costs. In th...

VSB – Technical University of Ostrava has a possibility to investigate changes in the rock massive during operation of heat pumps. Our new University Hall is heated up by the heat pumps. This object is the biggest building in the Czech Republic and in the Central Europe which uses this type of the system. Monitoring boreholes are situated in the area of heat pumps boreholes. They are equipped with heat sensors which monitor temperature changes in rock massive during the heat pumps operati on. This locality is ca...

The contribution shows the problems of unde rground coal gasification. Currently, this topic is timely, seeing that many coal deposits can not mine through traditional mining methods. Through underground gasification can be obtained from these deposits so- called synthetic gas - syngas, which can be conve rted into electricity or used in industry and households as fuel. Underground gasification technology has been verified in laboratory conditions for several experiments. Experiments differed fr om one by ways of ...

Iran is a country with an area of 1,648,198 Km 2 in the Middle East. When it comes to sun, there are 300 days of pure high UV sunshine in 95% of the country. There is a triangular great desert from center to the East of Iran, which due to its position receives a large amount of solar energy. Because this area is enclosed by the high ridge Alburz Mountains in the North, the Zagros Mountains in the West and the Makran Mountains in the East, there is no climate variability and also its geographi cal and environmental...

Slovakia falls behind the aims that were appointed in the field of the scrap economy. In our paper, we are concentrated on the valuatio n of the interest of Slovak citizens in the separated collection of the communal scrap in Slovak Republic, that is very low when talking about the mass. On the basis of th e questionnaire research we evaluate the interest in the separated co llection of communal scrap of citizens of the cities and villages acoording to the fact they live in habitable blocks, or in family houses . ...

As traditional organic fuel resources are being depleted in the modern world, energy crisis and environmental situation aggravate and the attention of the mankind is increasingly drawn towards untraditional, renewable sources of energy and opportunities of their efficient use. Georgia has significant geothermal resources concentrated in numerous thermal springs and basins. There are two main basins of thermal waters in Georgia. The water in the Kolkheti basin is distinguished for its low mineralization, it is over...

The Low Resource Consumption Buildings and Construction by Use of Life-Cycle Assessment in Design and Decision Making (LoRe-LCA) project aims to coordinate activities regarding the application of life-cycle assessment (LCA) in the European construction sector, focusing on comparing and improving the functional units used for LCA for whole buildings, improving the possibilities to compare results for different alternatives during design stage, and for comparison of results for different buildings. The project focus...

The paper treats aspects of revitalization and reconstruction of existing facilities – schools and kindergartens, in the context of sustainable development. The analysis of architectural opportunities is based on researching fund-building in Serbia, at first in Nis. Having in mind that existing facilities spend a great amount of energy in the phase of exploitation, the paper research the possibilities of rehabilitation schools and kindergartens in order to improve energy efficiency.