|
Latest Issue
 |
Login
- Category: Articles
Based on a real case study, this article addresses the issues that can be encountered during project planning when a wind resource assessment programme (WRAP) is not adequately designed. The study highlights the uncertainty induced by vertical and horizontal extrapolation of the wind resource. The impact of these parameters on energy production is demonstrated based on simulations using commercial wind resource models. The resulting conclusions highlight the importance of well-designed WRAPs. The experience, results, benefits and challenges of sodar (sound detection and ranging) use are briefly reviewed in the context of the complex terrain and operating conditions of Canada. Limitations encountered by numerical models (steady state wind flow model, CFD model) are also examined in a comparative case study.By Bouaziz Ait-Driss, Francis Pelletier, Milena Dimitrijevic and Christophe Sibuet-Watters, Helimax Energy, Canada
- Category: Articles
By Marian Klobasa, Fraunhofer Institute for Systems and Innovation Research, Germany
- Category: Articles
Reconciling a conflict between wind turbines and radio systems
Renewable energy is at the heart of government policy in most western countries as global warming and its causes rise to the top of political and public agendas.? At the same time, the public demand for further growth in communications and more mobility seems as insatiable as increased demand for energy.? But within these public aspirations lies a dilemma: wind turbines, the major source of growth in renewable energy, cause interference to radio communications upon which many telecommunication services depend.? Can these conflicts be resolved?? Radio engineers, recognising the importance of both renewable energy and radio communications are seeking ways to reconcile this conflict.By Adrian Grilli, the Joint Radio Company Ltd, UK
.- Category: Articles
At the present time 65% of Sri Lanka's electricity is generated by fossil fuels. In this situation, utilisation of renewable energy for electricity generation is very important to mitigate economic and environmental impacts. Wind energy has been identified as one of the more promising renewable energy sources that could generate electricity in Sri Lanka. However, it will be necessary to improve the quality and accessibility of renewable energy resource data before large-scale wind energy technologies can be developed locally. At present, ground wind measurements are not sufficient to accomplish a comprehensive wind resource assessment in Sri Lanka. For this reason, a high-resolution wind map has been developed by the US National Renewable Energy Laboratory. In this article, cost of wind power generation in various parts of Sri Lanka is discussed and compared to the existing power purchasing tariff system in the country.By Mahinsasa Narayana, National Engineering Research & Development Centre, Sri Lanka
.- Category: Articles
A Vision for Creating a More Powerful Europe
Airtricity is proposing the development of the Supergrid. This project consists of a series of interconnected offshore wind farms throughout the seas of Europe. It would be commonly owned by all European states, with the wind farms dispersed across a wide geographic area, ranging from the Baltic Sea to the Mediterranean and Atlantic. This broad arrangement could smooth out any intermittency of supply by capturing the wind and transmitting power from one end of the grid to the other to feed into national grids. In the event of the wind not blowing, it would also allow for the movement of brown (non-renewable) power, putting in place an infrastructure for an energy trading system. Supergrid would be implemented in stages, the first being an offshore wind farm in the North Sea called the 10GW Foundation Project. It would demonstrate the project’s feasibility by interconnecting the markets of the UK, the Netherlands and Germany and create economies of scale.
By Dr Eddie O’Connor, CEO and founder of Airtricity, Ireland
- Category: Articles
A multi-scheme ensemble prediction system has been successfully applied to the forecasting of wind energy in the Republic of Ireland. An accurate forecasting ability is critical for the safe, efficient and economical operation of the power system. Accurate forecasting has become particularly important because of the rapidly increasing proportion of wind-generated power in the small, synchronous Irish system and also because of the ?impending Single Electricity Market for the Republic and Northern Ireland. Results are presented here for forecasting the total wind generation of the power system. Geographical dispersion of wind farms and the use of ensemble prediction techniques – which allow? the forecast uncertainty to be quantified – should permit higher penetrations of wind generation on isolated and weakly interconnected power systems.By Steven J. Lang, University College Cork, Ireland
- Category: Articles
What Stock Prices and Wind Loads Have in Common
Extreme loads that occur only once or a few times in the life of a wind turbine play an important role in the design process. The time series of loads typically look like a mixture of oscillations and random fluctuations, the latter caused by the turbulent wind. From the fluctuating time series we need to be able to determine reliable loads equipped with probabilistic properties like ‘exceeded on average once within 50 years’. For a long time the methods used to determine ultimate loads for wind turbines have been relatively simplistic. However, nowadays, because of increasing turbine size and value, more sophisticated methods are recommended. In this article we give an introduction to extreme value theory that provides the tools to determine ultimate loads and also introduce our computer program GumbelWind as a tool for the practical application of the theory.
By M. Hänler and U. Ritschel, Windrad Engineering GmbH, Germany
