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Number of results: 17
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Abstract

The paper presents an analysis of the influence of the energy generated from renewable sources on an improvement in the energy efficiency of public utility building and households. It also presents the current state of the technologies for the production of electricity from renewable sources, as well as their share in the national power supply system. The conducted analysis concerns both micro, as well as large systems generating electricity. Systems generating power from renewable sources are gaining in popularity. With an increasing awareness in the society of the beneficial influence that renewable power generating systems have on the environment, as well as the support in form of various programs offering subsidies for the construction of new systems, power generation from renewable sources is becoming increasingly popular and common. Although the renewable energy systems are still not widely considered to be a profitable solution, systems using renewable sources of energy are positively perceived and treated as a new trend in the construction of multi or single-family residential buildings. The increasing share of the renewable energy in the national power supply system significantly reduces the demand for energy produced from conventional sources. This obviously translates into a reduced consumption of primary energy, for example, fossil fuels, and, in turn, leads to the reduced exploitation of natural resources, thus contributing to the protection of the natural environment. A reduced consumption of fossil fuels also means a significant reduction in environmental pollution during their processing into electricity or heat. Actions aiming at improving energy efficiency and reducing final energy consumption are being undertaken by many countries all over the world, and by the European Union. In 2012, the European Parliament and the Council issued Directive 2012/27/EU obliging the Member States to initiate actions aiming at a reduction in the consumption of final energy by 1.5% a year. The paper presents the current status of generation of energy from renewable sources during the last 13 years. The ways for using energy from the renewable sources to improve the energy efficiency of facilities were also discussed.
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Abstract

The article presents selected issues from the Polish Energy Policy draft until 2040. From many issues, the authors chose the ones they considered the most revolutionary. Firstly, the National Power System should be restructured to meet the challenges of a changing environment, be adapted to the growing demand for electricity, and at the same time have the least impact on the natural environment. These goals can be achieved through reforms to reduce the importance of coal in the energy mix and the development of renewable energy sources, especially offshore wind energy. The next tasks are the development of electromobility, enabling the reduction of pollution caused by transport, and, in the longer term, after 2030, the development of nuclear energy in place of the withdrawn coal power.
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Abstract

The energy efficiency of photovoltaic modules is one of the most important aspects in energetic and economic aspects of the project related to system installations. The efficiency of modules and the electricity produced by photovoltaic conversion in solar modules is affected by many factors, both internal, related to the module structure itself and its technical and external factors related to the energy infrastructure, which includes: cabling, inverters, climate conditions prevailing at the micro-installation location and the orientation and angle of inclination of the solar modules. The installation of photovoltaic modules should be preceded by an energy efficiency analysis, which will help to indicate the optimal solution adapted to the given conditions. The article presents a comparative analysis of the amount of energy produced under real and simulated conditions. Analyzes were made on the basis of research carried out in the Wind and Solar Energy Laboratory located at the AGH University of Science and Technology, data from solar irradiation data-bases and computer software for estimating energy resources. The study examined the correlation of the solar irradiation on the modules and the amount of electricity generated in the photovoltaic module. The electricity produced by the module was compared under real conditions and simulated based on two sources of data. The comparison and analysis of the amount of energy of the module were also made, taking simulated different angles of the module’s inclination into account.
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Abstract

Pollution, climate change and energy security are significant problems. Climate-disrupting fossil fuels are being replaced by clean and non-depletable sources of energy. It requires major changes to energy infrastructures and strong support for promotion of the use of energy from renewable sources. Renewable energy is emerging as a driver of inclusive economic growth and reinforcing energy security. Public entities have to promote renewable energy development by implementing cost-effective national support schemes. By acting at national-level, several barriers to public and private investments could be tackled, addressing the lack of coordination between various authorising bodies at national level and stimulatng the administrative capacity to implement energy projects. It should be effective in promoting transparency for investors and others economic operators. In Poland there is a lack of regulatory policies creating incentives for decentralised energy. Market-based support schemes are still needed for small-scale self-consumption system. Currently operating solutions have been shown in the contrast of the ones applied abroad. The development of clean energy technologies depends on many factors. The author identified few most important ones, mainly financial, regulatory issues, social, environmental and characterized them in this work. The article presents the recommendations of regulatory framework and some proposals for energy cluster based policy’s tools, the introduction of which would significantly facilitate the wider renewable energy uses in Poland.
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Abstract

The implementation of micro scale combined heat and power systems is one of the ways to improve the energy security of consumers. In fact, there are many available large and medium scale cogeneration units, which operate according to the Rankine Cycle. Due to European Union demands in the field of using renewable energy sources and increasing energy efficiency result in the importance of additionally developing systems dedicated for use in residential buildings, farms, schools and other facilities. This paper shows the concept of introducing thermoelectric generators into typical wood stoves: steel plate wood stoves and accumulative wood stoves. Electricity generated in thermoelectric generators (there were studies on both three market available units and a prototypical unit developed by the authors) may be firstly consumed by the system (to power controller, actuators, fans, pumps, etc.). Additional power (if available) may be stored in batteries and then used to power home appliances (light, small electronics and others). It should be noted that commercially available thermoelectric generators are not matched for domestic heating devices – the main problems are connected with an insufficient heat flux transmitted from the stove to the hot side of the generator (caused e.g. by the non -homogeneous temperature distribution of the surface and bad contact between the stove and the generator) and inefficient cooling. To ensure the high efficiency of micro cogeneration systems, developing a dedicated construction both of the generator and the heat source is necessary.
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Abstract

Hybrid Renewable Energy Systems connected to the traditional power suppliers are an interesting technological solution in the field of energy engineering and the integration of renewable systems with other energy systems can significantly increase in energy reliability. In this paper, an analysis and optimization of the hybrid energy system, which uses photovoltaic modules and wind turbines components connected to the grid, is presented. The system components are optimized using two objectives criteria: economic and environmental. The optimization has been performed based on the experimental data acquired for the whole year. Results showed the optimal configuration for the hybrid system based on economical objective, that presents the best compromise between the number of components and total efficiency. This achieved the lowest cost of energy but with relatively high CO2 emissions, while environmental objective results with lower CO2 emissions and higher cost of energy and presents the best compromise between the number of components and system net present cost. It has been shown that a hybrid system can be optimized in such a way that CO2 emission is maximally reduced and – separately – in terms of reducing the cost. However, the study shows that these two criteria cannot be optimized at the same time. Reducing the system cost increase CO2 emission and enhancing ecological effect makes the system cost larger. However, depends on strategies, a balance between different optimization criteria can be found. Regardless of the strategy used economic criteria – which also indirect takes environmental aspects as a cost of penalties – should be considered as a major criterion of optimization while the other objectives including environmental objectives are less important.
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Abstract

The large variability and unpredictability of energy production from photovoltaic power microinstallations results from the dependence on the current weather conditions. These conditions depend on a number of factors and are variable over the time. Despite this specificity, photovoltaic micro-installations are becoming more and more popular in the world and in Poland. This is mainly due to the fact that the generation of energy from renewable sources has numerous advantages, the energy is free, renewable in time and ecological, and its production on its own gives partial independence from energy supplies from the power grid. In addition, the observed significant prices decrease of solar modules has further accelerated the development of the use of this energy source. Concern for this method of energy production among households has increased significantly in Poland after introducing the prosumer in the legal framework and the use of administrative and financial support. The implemented prosumer mechanisms allowed, for example, the net balancing of the energy consumed and produced by the micro-installation through storage in the power grid. The article describes the problem of balancing sources using solar energy, based on micro-installation used in the household (the so-called prosumer installation). The conducted analyses compared the load profile of a typical household and the energy generation profile from a photovoltaic installation, determining the real balancing formation level of such a system.
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Abstract

The Polish energy sector is, to a large extent, based on fossil fuels used in conventional energy, which is not entirely consistent with the current energy policy of the European Union. Therefore, it is necessary to increase the use of renewable energy sources that guarantee the preservation of the value of the natural environment in rural areas. It should be emphasized that in addition to the economic effect, the environmental effect is very important, understood as the impact of renewable energy on the natural environment and the quality of life of rural residents. The intensive development of RES raises a lot of controversy among politicians, as well as among rural residents, who are also associated with the myths regarding renewable energy as harmful to the natural environment. Rural development should be connected with the socio-economic situation, and even more so with the socio-cultural situation of its inhabitants, because it assumes that the development of rural areas in Poland is associated not only with agriculture, but also with historical and natural values and their durability. The aim of this work is to determine the attitudes of the inhabitants of rural areas of the Podkarpackie Province on the impact of renewable energy sources on the natural environment. The work assumes that the durability of rural areas is largely connected with the ability to preserve their natural values, as well as ensuring a satisfactory quality of life for residents. The basic source of data was surveys carried out in 2017 among 282 inhabitants of the Podkarpackie Province .
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Abstract

The article discusses the importance of small hydro power plants in the Polish power system and defines the legal conditions for the operation of small hydro power plants. The phenomena occurring in the hydrological system of small hydro power plants and their impact on the natural environment were analyzed. An analysis of phenomena occurring in the hydrological system and the activity of small hydro power plants that are operating on the Radunia River helped us identify relations between different types of power plants working in cascades and possibilities of power generation control in period of several days. The above-mentioned analysis has been used in the development of a mathematical model of a hydroelectric plant and cascades of hydroelectric plants. The numerical simulations carried out concerned both the self-operating power plant and a cascade of two identical objects of this type. There is a possibility for small hydro power plant to run as a base load power plant and during periods of high demand as well (peak demand or unexpected loss of generation in the power system). A single hydroelectric power plant can deal with varying peak load demands while adding a second stage increase those abilities. A cascade of reservoir hydropower plants has a much greater ability to store energy and give it back in time. In addition, the existence of a second power plant equipped with a surge reservoir allows for a significant reduction in the amplitude of flows in the river below the cascade, which will reduce the negative impact of the cascade on the environment.
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Abstract

Using renewable energy sources for electricity production is based on the processing of primary energy occurring in the form of sun, wind etc., into electrical energy. Economic viability using those sources in small power plants strongly depends on the support system, based mainly on financial instruments. Micro-installations, by using special instruments dedicated to the prosumer market may become more and more interesting not only in terms of environmental energy, but also financial independence. In the paper, the term hybrid power plant is understood to mean a production unit generating electricity or electricity and heat in the process of energy production, in which two or more renewable energy sources or energy sources other than renewable sources are used. The combination of the two energy sources is to their mutual complementarity, to ensure the continuity of the electricity supply. The ideal situation would be if both sources of energy included in the hybrid power plant continuously covered the total demand for energy consumers. Unfortunately, due to the short-term and long-term variability of weather conditions, such a balance is unattainable. The paper assesses the possibility of balancing the hybrid power plant in daily and monthly periods. Basic types of power plants and hybrid components and system support micro-installations were characterized. The support system is based particularly on a system of feed-in tariffs and the possibility of obtaining a preferential loan with a subsidy (redemption of part of the loan size). Then, an analysis of energy and economic efficiency for a standard set of hybrid micro-installations consisting of a wind turbine and photovoltaic panels with a total power of 5 kW, were presented. Fourteen variants of financing, economic efficiency compared with the use of the method of the simple payback period were assumed.
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Abstract

The article describes selected issues falling within the scope of the technical analysis of a detached building’s heating system with a direct evaporation ground source heat pump installation. This paper covers the characteristics of modernized facility as well as calculations to determine the heat demand. What is more, the article describes the manner in which heat pumps shall be selected, its installation components as well as the receiving installation.
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Abstract

The paper presents the idea of a prosumer energy cloud as a new service dedicated to electricity prosumers. The implementation of the cloud should generate a number of benefits in the following areas: settlements between prosumer and electricity supplier, the development of distributed energy sources in microprocessors and the development of e-mobility. From the prosumer point of view, the proposed idea of a prosumer cloud of energy is dedicated to the virtual storage of energy excess generated in the micro-installation. Physical energy storage in the cloud means recording the volume of electricity introduced into the electricity system from the prosumer’s microprocessors. It is assumed that the energy equivalent to the volume registered in the prosumer cloud can be used at any time at any point in the network infrastructure of the National Power System. Any point of network infrastructure shall be understood as any locally located point of connection of an electricity consumer provided with access authorization. From the point of view of the power grid operators, the idea of a prosumer energy cloud is a conceptual proposition of a service dedicated to the new model of the power system functioning, taking future conditions concerning the significant development of prosumer energy and e-mobility into account. In this concept, electricity would be treated as a commodity only to partial physical storage and above all to trade. In this model a key aspect would be virtual energy storage, that is, the commercial provision by the cloud operator (trading company) of any use of the electricity portfolio by its suppliers. It should be stressed, however, that in the prosumer’s energy cloud functioning, a significant factor would be the cost of guarantees of the use of energy by prosumers at any time and point of connection to the network. This results in the need of taking the presence of certain market risks, both volumetric and cost incurred by clouds operator, which can be minimized by passing a portion of the accumulated volume of generated energy to the cloud operator into account. It should be emphasized that this article presents the first phase of the development of the concept of prosumer energy cloud. However, it is planned to be expanded by the following stages, which include the possibility of controlling and supervising the operation of prosumer installations such as: sources, receivers and physical energy stores, e.g. home energy storage or batteries installed in electric vehicles. Ultimately, it is assumed that the proposed prosumer energy cloud will be outside of the storage of energy (virtual and partly physical) and that aggregation of prosumer resources will create new possibilities for their use to provide a variety of regulatory services, including system ones.
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Abstract

The optimal energy management (OEM) in a stand-alone microgrid (SMG) is a challenging job because of uncertain and intermittent behavior of clean energy sources (CESs) such as a photovoltaic (PV), wind turbine (WT). This paper presents the effective role of battery energy storage (BES) in optimal scheduling of generation sources to fulfill the load demand in an SMG under the intermittency of theWT and PV power. The OEM is performed by minimizing the operational cost of the SMG for the chosen moderate weather profile using an artificial bee colony algorithm (ABC) in four different cases, i.e. without the BES and with the BES having a various level of initial capacity. The results show the efficient role of the BES in keeping the reliability of the SMG with the reduction in carbon-emissions and uncertainty of the CES power. Also, prove that the ABC provides better cost values compared to particle swarm optimization (PSO) and a genetic algorithm (GA). Further, the robustness of system reliability using the BES is tested for the mean data of the considered weather profile.
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Abstract

This paper presents the optimal sizing of PV/Wind/Fuel Cell/Battery Hybrid Energy System for energizing a Small Scale Industrial Application or a village domestic load of 200 kW. HOMER software is used for simulation of the complete system. The solar radiation data and wind speed data used in this paper are for the place of Coimbatore, Tamil Nadu, India which is located 11.0183° N longitude and 76.9725° E latitude. The optimized sizes of components of Hybrid Power System (HPS) are found based on Levelised Cost of Energy (LCE) and total Net Present Cost (NPC). The results are presented and compared for five different combinations of HPS components. Suggestions are also presented to choose the low cost system which produces energy at low LCE.
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