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Open access

G. Zaleskis

Abstract

Integration of renewable energy sources and the improvement of the technological base may not only reduce the consumption of fossil fuel and environmental load, but also ensure the power supply in regions with difficult fuel delivery or power failures. The main goal of the research is to develop the methodology of evaluation of the wind turbine economic efficiency. The research has demonstrated that the electricity produced from renewable sources may be much more expensive than the electricity purchased from the conventional grid.

Open access

G. Zaleskis and I. Rankis

Abstract

According to the strategical objectives of the use of the renewable energy sources, it is important to minimise energy consumption of conventional power grid by effective use of the renewable energy sources and provi-ding stable operation of the consumers. The main aim of research is to develop technical solutions that can provide effective operation of the wind generators in the small power DC microgrids, which also means wind energy conversion at as wider generator speed range as possible.

Open access

A. Sokolovs, L. Grigans, E. Kamolins and J. Voitkans

Abstract

The authors present a small-scale wind turbine emulator based on the AC drive system and discuss the methods for power coefficient calculation. In the work, the experimental set-up consisting of an AC induction motor, a frequency converter, a synchronous permanent magnet generator, a DC-DC boost converter and DC load was simulated and tested using real-life equipment. The experimentally obtained wind turbine power and torque diagrams using the emulator are in a good agreement with the theoretical ones.

Open access

Maria Alexandra Nichifor

Abstract

Renewable energy has become a crucial element for the business environment as the need for new energy resources and the degree of climate change are increasing. As developed economies strive towards greater progress, sustainable business models are of the essence in order to maintain a balance between the triple bottom line: people, planet and profit. In recent years, European Union countries have installed important capacities of renewable energy, especially wind and solar energy to achieve this purpose. The objective of this article is to make a comparative study between the current sustainable business models implemented in companies that are active in the wind and solar energy sector in Romania. Both sectors underwent tremendous changes in the last two years due to changing support schemes which have had a significant influence on the mechanism of the renewable energy market, as well as on its development. Using the classical Delphi method, based on questionnaires and interviews with experts in the fields of wind and solar energy, this paper offers an overview of the sustainable business models of wind and solar energy companies, both sectors opting for the alternative of selling electricity to trading companies as a main source of revenue until 2013 and as the main future trend until 2020. Furthermore, the participating wind energy companies noted a pessimistic outlook of future investments due to legal instability that made them to reduce their projects in comparison to PV investments, which are expected to continue. The subject of the article is of interest to scientific literature because sustainable business models in wind and photovoltaic energy have been scarcely researched in previous articles and are essential in understanding the activity of the companies in these two fields of renewable energy.

Open access

Leszek Dawid

Abstract

European energy system is undergoing a deep transition to low-emission energy sources, mainly wind farms. This transition is caused mostly by energy politics of European Union (EU) and its goals in the topic of renewable energy. European wind energy is dominated by Germany that produces half of total wind energy in EU. The aim of this article is to present support systems for wind farms existing in Germany in the context of introducing in Poland the Act of 20 May 2016 on Wind Energy Investments limiting onshore wind farms localization and Act of 22 June 2016 introducing changes to the Act on Renewable Energy Sources (RES) and some other acts. It is postulated to make amendments of acts regulating RES while considering German solutions.

Open access

Leszek Dawid

Abstract

At the end of 2016 there were 84 wind farms under construction in 11 European countries. Investments in this sector are enormous. The average cost of a wind farm construction amounts to approx. 4 mln EUR per 1 MW of installed power. Offshore wind energy production also plays a significant role in the process of ensuring energy security in Europe, and in reduction of greenhouse gases. The objective of this paper is to present prospects of offshore wind energy farms development in the leading member states of the European Union as regards this problem. In this paper offshore wind farms in Germany and Denmark have been studied. In the paper the power of wind farms, the support systems as well as criteria related to location of wind farm offshore have been analysed. German and Danish sectors of offshore wind energy are strongly supported by respective governments. Both countries aim at yearly increase of wind energy share in total energy production. The research has been conducted based on the analysis of acts, regulations, the subject’s literature and information from websites.

Open access

Maria Alexandra Nichifor

Abstract

Wind energy experienced an exponential development in the past two decades, forming a main source of energy today, but also a frequently encountered issue of debate due to the increased proximity of wind turbines to citizens’ residence, especially in the case of the Western part of the European Union. Although the benefits of renewable sources of energy represent a compulsory effort towards ensuring sustainable energy strategies for the future, due to the increased pressure of balancing climate change, limitation of traditional energy resources and economic competition, the expansion of wind parks has caused strong reactions of local communities in many regions leading to the reorganization of public exposure strategies of many companies in the field. This research intends to offer a sample of public perceptions of wind turbines depending on several influence factors, based on the answers of 64 Dutch citizens and 40 Romanian respondents. Through the implementation of the Delphi method based on questionnaires and interviews, an overview of perceptions towards placement of wind turbines in the two analyzed countries has been offered, providing significant answers to the influence factors of public reactions for or against wind turbines. The main results of the research revealed the importance of financial benefits in increasing public acceptance of wind farms, as well as several subjective factors, such as the visual impact of wind turbines and onshore or offshore placement, that contribute to a positive or negative behavior of citizens towards it.

Open access

A. Mutule and O. Kochukov

Abstract

An approach is proposed to the modelling of wind farms in the electric power system long-term planning. It allows a specialist to perform calculations based on scanty information and offers a set of ready-to-use data for easy, fast, and precise modelling. The authors exemplify the calculations of wind speed probability density and power curves and give an idea for relevant corrections. They also show how to pass from a single wind turbine model to the unified model of multiple wind turbines which would meet the requirements of long-term planning tasks. The paper presents the data on wind farms that are operating in UK and Oceania

Open access

S. Aniskevich, V. Bezrukovs, U. Zandovskis and D. Bezrukovs

Abstract

The paper studies spatial wind energy flow distribution in Latvia based on wind speed measurements carried out at an altitude of 10 m over a period of two years, from 2015 to 2016. The measurements, with 1 min increments, were carried out using certified measuring instruments installed at 22 observation stations of the Latvian National Hydrometeorological and Climatological Service of the Latvian Environment, Geology and Meteorology Centre (LEGMC). The models of the spatial distribution of averaged wind speed and wind energy density were developed using the method of spatial interpolation based on the historical measurement results and presented in the form of colour contour maps with a 1×1 km resolution. The paper also provides the results of wind speed spatial distribution modelling using a climatological reanalysis ERA5 at the altitudes of 10, 54, 100 and 136 m with a 31×31 km resolution. The analysis includes the comparison of actual wind speed measurement results with the outcomes of ERA5 modelling for meteorological observation stations in Ainazi, Daugavpils, Priekuli, Saldus and Ventspils.

Open access

Jakub Edward Zaleski

Abstract

This article is focused on analysing the present state of renewable electricity production and consumption coverage in Germany, concentrating on the intermittence of wind and solar energy production and considering the significance of the wind silence phenomenon. The development and promotion of renewable energy is a major goal set out by politicians of which one example is the German plan “Energiewende”.

The author examines wind and solar energy complementarity and attempts assessing the possibility of basing Germanys’ electricity production on renewable energy sources, without significant advancements in technology and changes in consumer behaviour. Using the analysis based on hourly data of consumption and production by source of electricity in Germany in 2016, the research addresses the issues of renewable energy source effectiveness, intermittence and points to the critical matter of periodical unavailability of wind and solar energy.