The threatening impacts of climate change are driving a global revolution towards cleaner sources of energy. In South Africa, strategies for energy security and emissions reduction are focusing on renewables, wind energy being one of the most promising ones. The construction of wind energy projects has attached limitations in the identification of suitable areas that respect the environment and are technically feasible. Herein, site selection criteria has been grouped into the Site Identification group (SIG), and the Resource & Energy Generation group (R&E). The SIG incorporates technical, environmental and restricted criteria within a spatial frame; while R&E accounts for the wind resource, estimated energy generation and fitting to energy demand profiles under a spatial-temporal frame. The average wind resource is usually found to be analysed together within the technical factors to determine the feasibility of a site; however for this study, a different and independent treatment of the wind resource and its energy generation profile was undertaken. It consists of evaluating the unique hourly wind power profile of each site against the energy consumption profile for the same period. The need is for selecting places with the smallest variation between the electricity produced and the electricity demanded. The Production to Demand Difference (PDD) has been chosen as the indicator of such variations. Therefore, the new purpose is to identify spots where the combination of the PDD and the results from the SIG become smaller with time. The Mean Difference (MD) is also taken into account to obtain further information regarding the trends of the differences. Geoprocessing, overlays and mathematical combinations of datasets are all performed under a GIS environment. / Dissertation (MEng)--University of Pretoria, 2015. / tm2015 / Chemical Engineering / MEng / Unrestricted

Turkey wants to encourage renewable electricity generation to reduce dependence on imported natural gas and meet its highly growing power demand. The government’s objective is to increase the share of renewable resources in electricity generation to at least 30 percent by 2023, and the specific target for the installed wind energy capacity is 20 GW by that date. Fortunately, Turkey has an enormous wind energy potential to exploit for electricity generation. When from “good” to “outstanding” wind clusters are taken into account, the overall technical wind power generation capacity in Turkey is calculated to be nearly 48 GW. In this context, this thesis investigates whether policy instruments in the Turkish regulatory frame contribute to economic viability for wind power projects or not. The financial results point out that an electricity price of 7.3 USD cent/kWh, which is the guaranteed price for wind power generation by current regulations, does not make a typical onshore wind power plant located in a “good” windy resource economically viable. However, when locally produced wing blades and turbine towers are used in the project, the purchase price increases to 8.7 USD cent/kWh, and the project becomes economically viable. As a result, the local content element introduced in recent regulations promotes wind energy investments and helps government to reach its renewable target for 2023. / text

Saudi Arabia has been trying to change its long tradition of relying on fossil fuels and seek renewable energy sources such as wind power. In this thesis, I firstly provide a comprehensive assessment of wind energy resources and associated spatio-temporal patterns over Saudi Arabia in both current and future climate conditions, based on a Regional Climate Model output. A high wind energy potential exists and is likely to persist at least until 2050 over a vast area ofWestern Saudi Arabia, particularly in the region between Medina and the Red Sea coast and during Summer months. Since an accurate assessment of wind extremes is crucial for risk management purposes, I then present the first high-resolution risk assessment of wind extremes over Saudi Arabia. Under the Bayesian framework, I measure the uncertainty of return levels and produce risk maps of wind extremes, which show that locations in the South of Saudi Arabia and near the Red Sea and the Persian Gulf are at very high risk of disruption of wind turbine operations. In order to perform spatial predictions of the bivariate wind random field for efficient turbine control, I propose parametric variogram matrix (function) models for cokriging, which have the advantage of allowing for a smooth transition between a joint second-order and intrinsically stationary vector random field. Under Gaussianity, the covariance function is central to spatio-temporal modeling, which is useful to understand the dynamics of winds in space and time. I review the various space-time covariance structures and models, some of which are visualized with animations, and associated tests. I also discuss inference issues and a case study based on a high-resolution wind-speed dataset. The Gaussian assumption commonly made in statistics needs to be validated, and I show that tests for independently and identically distributed data cannot be used directly for spatial data. I then propose a new multivariate test for spatial data by accounting for the spatial dependence. The new test is easy to compute, has a chi-square null distribution, and has a good control of the type I error and a high empirical power.

nÃo hà / The main objective of this work is to present a site evaluation study for the Power performance generator of small scale wind turbines (AEPP). The Brazilian norm ABNT NBR IEC 61400-12-1 and its annexes A (obstacle valuation) and B (terrain assessment) were used as reference. Two source codes were written in the R language in order to automate the evaluation process. Both source codes were validated through direct comparison between the results of the developed R codes and the results obtained by DNV GL, which has ISO17025 international laboratory certification for power performance measurements of wind turbines according to the IEC standard. The validated code was then used to evaluate possible positions for the AEPP power performance measurement in UFC. The topographic map was downloaded from the free database SRTM and the characteristic obstacles were determined by satellite images and photos of the area. Altogether, three areas and their respective pairs AEPP â anemometric tower were analyzed regarding their available measurement sector and the necessity or not to perform site calibration. / Este trabalho tem o objetivo de apresentar o estudo de avaliaÃÃo do local para mediÃÃo de curva de potÃncia de aerogeradores de pequeno porte (AEPP). Foi utilizada como referÃncia a norma brasileira ABNT NBR IEC61400-12-1 e seus anexos A (avaliaÃÃo de obstÃculos) e B (avaliaÃÃo do terreno). Foram escritos dois cÃdigos-fonte na linguagem R para automatizar o processo de avaliaÃÃo. Os cÃdigos-fonte foram validados por comparaÃÃo direta entre os resultados obtidos pelos cÃdigos desenvolvidos em R e os resultados obtidos pela empresa DNV GL, que possui certificaÃÃo internacional de laboratÃrio ISO17025 para mediÃÃo de curva de potÃncia de aerogeradores segundo a norma IEC. O cÃdigo validado foi entÃo utilizado para avaliar possÃveis locais para mediÃÃo de curva de potÃncia de AEPP na prÃpria UFC. O mapa topogrÃfico do local foi adquirido da base de dados gratuita SRTM e os obstÃculos do local foram caracterizados por imagens de satÃlite e fotos da regiÃo. No total, trÃs Ãreas e os respectivos pares AEPP â torre anemomÃtrica foram analisados em relaÃÃo ao setor de mediÃÃo disponÃvel e a necessidade ou nÃo de calibraÃÃo do local.

Diplomová práce pojednává o výrobě elektrické energie větrnými elektrárnami a jejím vlivu na napěťovou stabilitu v synchronně propojené elektrizační soustavě kontinentální Evropy. Úvod práce je obecně zaměřen na problematiku větrné energetiky se zaměřením na nejčastěji používané generátory pro větrné turbíny. V další části práce je proveden rozbor instalované kapacity větrných elektráren v zemích synchronně propojené elektrizační soustavy kontinentální Evropy a jsou představeny scénáře růstu větrné energetiky do budoucna. V rámci těchto zemí je také zařazen přehled potenciálu větrné energie na pevnině a na moři. Dále je práce zaměřená na napěťovou stabilitu, kde je pojednáno o kompenzačních prostředcích a možnostech regulace napětí. Závěr teoretické části je věnován možnostem předpovědi počasí a dopadu změn počasí na výrobu elektrické energie. V praktické části diplomové práce byla provedena simulace plánované větrné farmy a sledování jejího vlivu na napěťovou stabilitu v konkrétní části přenosové soustavy.