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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

BULK SYSTEM ADEQUACY ASSESSMENT INCORPORATING WIND AND SOLAR ENERGY

2016 March 1900 (has links)
Renewable energy sources have received increasing attention in electric power systems around the world due to growing environmental concerns. Wind and solar are among the most promising alternatives to conventional energy generation. There has been a rapid growth of wind and solar energy integration in power systems in the last decade, and is expected to grow further in the years to come. The main concern with wind and solar energy sources is the uncertainty and the intermittency of power generation, which leads to problems in maintaining the overall system reliability. The impacts of these sources on bulk system reliability depend on a large number of factors. The strength of the wind or solar resource at the installation site, the existing renewable power penetration level in the system, the points of connection of these sources to the power grid, the correlation in resource availability between multiple installation sites, and the correlation between the load and the renewable power are key factors that are analyzed in this thesis. These factors are considered in evaluating the bulk system reliability and reliability benefits of wind and solar power sources, and the reliability worth to the electricity customers from the addition of these energy sources. The IEEE-RTS test system is utilized throughout the thesis to evaluate the effects of these factors on bulk system adequacy. Swift Current and Saskatoon wind resources are modeled and utilized in this thesis. The Swift Current area has a strong wind resource and provides better reliability benefit and reliability worth than the Saskatoon wind resource. The benefits from wind and solar power integration, however, also depend significantly on the location where it is connected to the grid network. Wind farms that are diversified in multiple regions with independent wind speed profiles provide superior reliability benefits and worth than wind farms located in one region. The incremental benefits of adding wind or solar power decreases as the renewable power penetration is increased in the power system. Wind power at practical locations provides higher reliability benefits than photovoltaics. However, the daytime contribution of photovoltaics to system reliability is relatively high. The reliability benefits and reliability worth of solar power are significantly different for different seasons. A comparison study on reliability benefit and worth between a wind integrated bulk system and a solar integrated bulk system is also done in this thesis in order to identify the best option for bulk system reliability.
12

Comparison of optimization for non linear and linear wind resource grids

Dragoi, Ion January 2013 (has links)
The aim of this thesis is to assess how the configuration of linear and non-linearwind resource grids impacts the optimization.Three different software tools are used for this study: WAsP (linear model) includedin WindPRO, and WindSim (a non-linear model) - a CFD tool, and WindPRO forthe optimization. With the same configuration for wind resources, WAsP andWindSim will run to calculate the wind resource grids, .rsf or .wrg format, whichwill be compared in the post processing tab of WindPRO (from CFD interface).Using different optimization algorithms, the results from two software will becompared. The test site is flat terrain in the sea with no complexity (0,0002roughness and no orography or obstacle), and the chosen turbine here is Enercon40.3 (55m hub height, with the rated power at 14 m/s), and the wind is coming fromone direction, in our case North, which means sector 0.After comparison of the resource files from linear and non-linear wind resourcegrids, the optimization and comparison is ran for the two wind resource grids (linearand non-linear). The results of the optimization are also compared with optimizationresults of Eftun Yilmaz’s thesis (Eftun Yilmaz, 2013). We can see from the resultsthat WindSim gives almost 40% bigger values for the production. The results arecomparable with findings of Eftun Yilmaz thesis.
13

APPLICATION AND VALIDATION OF THE NEW EUROPEAN WIND ATLAS: WIND RESOURCE ASSESSMENT OF NÄSUDDEN AND RYNINGSNÄS, SWEDEN

Cho, Heeyeon January 2020 (has links)
The New European Wind Atlas (NEWA) was developed with an aim to provide high accuracy wind climate data for the region of EU and Turkey. Wind industry always seek for solid performance in wind resource assessment, and it is highly affected by the quality of modelled data. The aim of this study is to validate the newly developed wind atlas for two onshore sites in Sweden. Wind resource assessment is conducted using NEWA mesoscale data as wind condition of the sites. AEP estimation is performed using two different simulation tools, and the results of estimation are compared to the actual SCADA data for the validation of NEWA. During the process of simulation, downscaling is executed for the mesoscale data to reflect micro terrain effects. The result of the current study showed that NEWA mesoscale data represents wind climate very well for the onshore site with simple terrain. On the other hand, NEWA provided overestimated wind speeds for the relatively complex onshore site with forested areas. The overestimation of wind speed led to predict AEP significantly higher than the measurements. The result of downscaling showed only little difference to the original data, which can be explained by the sites’ low orographic complexity. This study contributes to a deeper understanding of NEWA and provides insights into its validity for onshore sites. It is beyond the scope of this study to investigate whole region covered by NEWA. A further study focusing on sites with higher orographic complexity or with cold climate is recommended to achieve further understanding of NEWA.
14

THE WIND OF CHANGE – SENSITIVITY OF THREE PARAMETERS ON WIND POWER ENERGY CALCULATIONS USING WINDPRO SOFTWARE

Skuja, Nina January 2023 (has links)
Many parameters used for Wind Resource Assessment (WRA) have uncertainty and variability, yet are input into the process as single values. The extent of the uncertainty or variance may not be known, and may or may not be significant enough to affect output. This Thesis focused on the energy calculation element of WRA, to assess the affect that errors (uncertainty) in three key user inputs had on the energy results. A parameter was chosen from each of the main groups influencing the energy calculation: wind speed (atmosphere), surface roughness (site conditions), and power curve (turbine technology). Reasonable variation due to uncertainty for wind speed and power curve were taken from other studies and their application simplified. Roughness change was assessed over the 5 classes (Class 0 (water) to 4 (dense forest/city)). WindPRO software was used to calculate the Annual Energy Production (AEP) and applied to three different wind turbine generators at the same coordinate. A sensitivity analysis was done on the AEP results using a hybrid One-At-a-Time Local Sensitivity Analysis by determining percentage changes from baselines and an overall rate of change for those key input parameters. The results showed that roughness class change effect was not linear. Changing from Class 0 to 1, AEP was on average -8±1%. Class 1 to 2 change was on average ‑12±1%. Class 2 to 3 change was on average -20±2%. Class 3 to 4 change was on average -29±2%. The wind speed change effect was found to be roughly linear. If mean wind speed has an error of ±10%, the AEP could be expected to be out by approximately +18/‑17% with a standard deviation of +4/-3%. The power curve change effect was also roughly linear. A PC±9% error leads to an approximate +6/-7% AEP error with a standard deviation of ±1%. Roughness class change was the most sensitive parameter to AEP with a 14.5 average rate of change, followed by wind speed at 1.8, then power curve with a 0.8 rate. Results compared reasonably well with other relevant studies.
15

INVESTIGATION OF POTENTIAL REASONS TO ACCOUNT FOR THE UNDERPERFORMANCE OF AN OPERATIONAL WIND FARM

Tücer, Renas January 2016 (has links)
Wind farms are costly projects and prior to the construction, comprehensive wind resource assessment processes are carried out in order to predict the future energy yield with a reliable accuracy. These estimations are made to constitute a basis for the financial assessment of the project. However, predicting the future always accommodates some uncertainties and sometimes these assessments might overestimate the production. Many different factors might account for a discrepancy between the pre-construction wind resource assessment and the operational production data. This thesis investigates an underperforming wind farm in order to ascertain the reasons of a discrepancy case. To investigate the case, the relevant data and information along with the actual production data of three years are shared with the author. Prior to the construction, a wind resource assessment was carried out by an independent wind consultancy company and the work overestimated the annual energy production (AEP) by 19.1% based on the average production value of available three years. An extensive literature review is performed to identify the possible contributing causes of the discrepancy. The data provided is investigated and a new wind resource assessment is carried out. The underestimation of the wind farm losses are studied extensively as a potential reason of the underperformance. For the AEP estimations, WAsP in WindPro interface and WindSim are employed. The use of WindSim led to about 2-2.5% less AEP estimations compared to the results of WAsP. In order to evaluate the influence of long term correlations on the AEP estimations, the climatology datasets are created using the two different reanalysis datasets (MERRA and CFSR-E) as long term references. WindSim results based on the climatology data obtained using the MERRA and CFSR-E datasets as long term references overestimated the results by 10.9% and 8.2% respectively.
16

Evaluation of the wind patterns over the Yucatán Peninsula in México

Soler-Bientz, Rolando January 2010 (has links)
Wind power is seen as one of the most effective means available to combat the twin crises of global climate change and energy security. The annual market growth has established wind power as the leading renewable energy technology. Due to the availability of sparsely populated and flat open terrain, the Yucatán Peninsula located in eastern México is a promising region from the perspective of wind energy development but no comprehensive assessment of wind resource has been previously published. A basic requirement when developing wind power projects is to study the main characteristic parameters of wind in relation to its geographical and temporal distribution. The analysis of diurnal and seasonal wind patterns are an important stage in the move towards commercial exploitation of wind power. The research developed during the PhD has comprehensively assessed the wind behaviour over the Yucatán Peninsula region covering long term patterns at three sites, a spatial study using short term data for nine sites, a vertical profile study on one inland site and an offshore study made on a pier at 6.65km from the North shore. Monthly trends, directional behaviours and frequency distributions were identified and discussed. The characteristics of the wind speed variation reflected their proximity to the coast and whether they were influenced by wind coming predominantly from over the land or predominantly from over the sea. The atmospheric stability over the eastern seas was also analysed to assess thermal effects for different wind directions. Diurnal wind speed variations are shown to be affected in particular by the differing wind conditions associated with fetches over two distinct offshore regions. Seasonal behaviour suggests some departure from the oscillations expected from temperature variation. The offshore wind is thermally driven suggesting largely unstable conditions and the potential development of a shallow Stable Internal Boundary Layer.
17

Wind Power Potential in Palestine/Israel : An investigation study for the potential of wind power in Palestine/Israel, with emphasis on the political obstacles

Odeh, Yousre January 2011 (has links)
Wind resource assessment studies have been conducted in the Israeli side and the Palestinian side before; however, the previous studies were restricted with the political border either Palestinian or Israeli except one of them that was based on measurements dated to 1940-1983 (R. Shabbaneh & A. Hasan, 1997). Moreover, the studies were performed years ago, with simple techniques and based on old data (R. Shabbaneh & A. Hasan, 1997). Hence, the needs for a new study that is based on updated data, and using updated model is highly demanded. This study is intended to perform wind resource assessment in Palestine/Israel; the study has used two stages of assessment, primary one based on reference station data on both sides, Israeli and Palestinian. The second stage of wind resource assessment is based on WindPRO software. The wind resource assessment ends up with identifying sites with higher potential that are situated in four selected sites, North of Palestine/Israel, North of West-bank, Jerusalem, and Eilat, the higher potential was in Eilat area bearing mean wind speed of 9.88m/s at 100 m hub height.Moreover, the study recognized the importance of political situation assessment due to the Israeli-Palestinian conflict. Based on conducted survey, the political situation assessment concluded that international non-governmental organizations seem to be most capable of starting up wind power project in Palestine/Israel. Furthermore, the study concluded that supportive policies from both the Israeli and Palestinian governments are crucial to promote wind power projects in the region.
18

A influência da duração da campanha de medição anemométrica na avaliação de recursos eólicos com base na aplicação de métodos MCP / The influence of the wind measurement campaigns span on a MCP-based wind resource assessment.

Miguel, José Vítor Pereira 10 November 2016 (has links)
Impulsionado pela mecânica de leilões de energia, o aproveitamento energético de recursos eólicos no Brasil atravessa um momento de expansão em participação na matriz de energia elétrica nacional. Não obstante, o desempenho da geração dos parques eólicos que estão em operação foi monitorado e apresentou, em média, resultados aquém daquilo que fora confiado ao Sistema Interligado Nacional, revelando que as estimativas de geração projetadas e declaradas por alguns dos projetos vencedores dos processos licitatórios podem ter sido supervalorizadas. Tal cenário provocou a exigência de medidas mais conservadoras para participação nos leilões de energia, como a já vigente adoção do P90 no cálculo da Garantia Física e o aumento da duração da campanha de medição anemométrica, a entrar em rigor a partir de 2017. Sendo o vento uma variável estocástica, existem incertezas intrínsecas à Avaliação de Recursos Eólicos que influenciam no processo de estimação da geração por um parque eólico e que devem, desta forma, ser identificadas, quantificadas e reduzidas, na medida do possível. Nesse sentido, este trabalho estuda a influência da duração da campanha de medição anemométrica na Avaliação de Recursos Eólicos com base na aplicação do método MCP ferramenta imprescindível no processo de caracterização do regime eólico no longo prazo com vistas para aprimorar a exatidão das previsões de geração pela fonte eólica. Para tanto, foram utilizadas quatro bases de dados contendo séries temporais de velocidade e direção do vento referentes a uma região de interesse. Inicialmente, nove diferentes métodos MCP foram testados e comparados, sendo que o método Vertical Slice aplicado com auxílio do software Windographer destacou-se dos demais e mostrou-se mais aderente aos dados utilizados conforme as métricas de Erro Absoluto Médio e Raiz Quadrada do Erro Quadrático Médio. Posteriormente, as bases de dados foram configuradas para simular campanhas de medição anemométricas com durações que variavam de 2 a 6 anos, de modo a avaliar o comportamento da incerteza relativa à caracterização histórica de recursos eólicos e analisar em que medida esta incerteza impacta no cálculo da estimativa de geração de eletricidade por um conjunto de aerogeradores hipoteticamente dispostos naquele local de interesse. Foi possível verificar que, para os dados e casos analisados, à medida que se aumentou a duração da campanha de medição anemométrica, a incerteza da caracterização histórica de recursos eólicos sofreu queda significativa; determinando, por conseguinte, redução da incerteza total que permeia a geração eólica. Ademais, a quantidade de energia estimada para o parque eólico hipotético exemplificado também decresceu, permitindo melhora na acurácia da previsão de geração e beneficiando a confiabilidade da fonte eólica no sistema elétrico brasileiro. / Driven by the energy auctions system, the energetic harnessing of wind resource in Brazil is now going through a phase of expansion in participation in the national electric energy mix. Nevertheless, the performance of power generation of in-operation wind farms was monitored and the results proved to be, on average, below what was initially entrusted to the National Grid System, indicating that the energy production estimations projected by some energy auctions winners could have been overestimated. This scenario has caused the requirements for participating in the energy auctions to be more conservative, with measures such as the adoption of the P90 on the calculation of the physical guarantee and the increase of the wind measurement campaigns time span the latter to be enforced as of 2017. The wind is a stochastic resource, hence there are uncertainties intrinsic to the Wind Resource Assessment that influence a wind farms power generation estimation and that need to be properly identified, quantified and reduced, as far as possible. In this respect, the influence of a wind measurement campaigns time span on the Wind Resource Assessment based on MCP methods an important tool in the process of characterizing the long-term wind regime was studied in order to detect the potential of enhancing the accuracy of wind power generation forecasts. For this purpose, four databases containing time series of wind speed and direction belonging to a target site were used. Firstly, nine different MCP methods were tested and compared, of which the Vertical Slice method implemented on the software Windographer outperformed all the others according to the Mean Absolute Error and Root Mean Square Error metrics. Subsequently, the databases were set to simulate campaigns with time spans varying from 2 to 6 years, in such a way to evaluate the behavior of the uncertainty in the long-term wind speed and to analyze how this uncertainty impacts the calculation of the energy production estimation of an array of wind turbines hypothetically placed on that target site. From the analyzed data and cases, it was verified that, as the wind measurement campaigns time span was increased, the uncertainty in the long-term wind speed was significantly diminished, thereby reducing the overall uncertainty that pervades the wind power harnessing. Furthermore, the energy production estimation of the exemplified hypothetical wind farm also decreased, allowing an improvement on the accuracy of the energy generation prediction and benefiting the reliability of wind power in the Brazilian electric system.
19

Wind resource assessment for posibel wind farm development in Dekemhare and Assab, Eritrea

Negash, Teklebrhan January 2018 (has links)
Recently wind resource assessment studies have become an important research tool to identify the possible wind farm locations.  In this thesis work technical analysis was carried out to determine the wind resource potential of two candidate sites in Eritrea with help of suitable software tools. The first site is located along the Red Sea cost which is well known for its wind resource potential, whereas the second site is located in the central highlands of Eritrea with significant wind resource potential. Detailed wind resource assessment, for one year hourly weather data including wind speed and wind direction, was performed for the two candidate sites using MS Excel and MATLAB. The measured wind data at Assab wind site showed that the mean wind speed and power density was 7.54 m/s and 402.57 W/m2 , whereas the mean wind speed and mean power density from Weibull distribution was 7.51 m/s and 423.71 W/m2 respectively at 80m height. Similarly, the measured mean wind speed and mean power density at Dekemahre wind site was obtained to be 5.498 m/s and 141.45 W/m2, whereas the mean wind speed and mean power density from Weibull distribution was 5.4859m/s and 141.057W/m2 respectively. Based on the analysis results Assab wind site classified as wind class-III and Dekemhare as wind class-I.  Wind farm modeling and Annual Energy Production (AEP) estimation was performed for E-82 & E-53 model turbines from Enercon Company with the help of MATLAB and Windpro software. The analysis revealed that Assab wind farm was an ideal site for wind energy production with capacity factor (CF) 53.4% and 55% for E-82 and E-53 turbines respectively. The gross and net AEP for turbine E-82 at Assab wind farm was 469.5 GWh and 446.025 GWh respectively with 95% park efficiency. Similarly, the analysis showed that the CF in Dekemhare site was very low with typical value 14.2% and 15.26% for E-82 and E-53 turbines respectively. The gross and net AEP of that site for model turbine E-53 was 53.5 GWh and 50.825 GWh respectively with 5% wake loss. Finally, a simplified economic analysis was carried out to determine the economic feasibility of possible wind power projects in both sites by assuming investment cost 1600 €/kW for E-82 turbine and 2000 €/kW for E-53 turbine. The total wind farm investment cost was found to be 215.85 and 107.93 Million Euro for E-82 and E-53 model turbines respectively. The levelized cost of energy at Assab and Dekemhare wind farm for E-82 model turbine was 0.0307 €/kWh and 0.5526 €/kWh respectively. The analysis result show that the levelized cost of energy in Dekemhare wind fasrm was much higher than that of Assab wind farm.
20

A influência da duração da campanha de medição anemométrica na avaliação de recursos eólicos com base na aplicação de métodos MCP / The influence of the wind measurement campaigns span on a MCP-based wind resource assessment.

José Vítor Pereira Miguel 10 November 2016 (has links)
Impulsionado pela mecânica de leilões de energia, o aproveitamento energético de recursos eólicos no Brasil atravessa um momento de expansão em participação na matriz de energia elétrica nacional. Não obstante, o desempenho da geração dos parques eólicos que estão em operação foi monitorado e apresentou, em média, resultados aquém daquilo que fora confiado ao Sistema Interligado Nacional, revelando que as estimativas de geração projetadas e declaradas por alguns dos projetos vencedores dos processos licitatórios podem ter sido supervalorizadas. Tal cenário provocou a exigência de medidas mais conservadoras para participação nos leilões de energia, como a já vigente adoção do P90 no cálculo da Garantia Física e o aumento da duração da campanha de medição anemométrica, a entrar em rigor a partir de 2017. Sendo o vento uma variável estocástica, existem incertezas intrínsecas à Avaliação de Recursos Eólicos que influenciam no processo de estimação da geração por um parque eólico e que devem, desta forma, ser identificadas, quantificadas e reduzidas, na medida do possível. Nesse sentido, este trabalho estuda a influência da duração da campanha de medição anemométrica na Avaliação de Recursos Eólicos com base na aplicação do método MCP ferramenta imprescindível no processo de caracterização do regime eólico no longo prazo com vistas para aprimorar a exatidão das previsões de geração pela fonte eólica. Para tanto, foram utilizadas quatro bases de dados contendo séries temporais de velocidade e direção do vento referentes a uma região de interesse. Inicialmente, nove diferentes métodos MCP foram testados e comparados, sendo que o método Vertical Slice aplicado com auxílio do software Windographer destacou-se dos demais e mostrou-se mais aderente aos dados utilizados conforme as métricas de Erro Absoluto Médio e Raiz Quadrada do Erro Quadrático Médio. Posteriormente, as bases de dados foram configuradas para simular campanhas de medição anemométricas com durações que variavam de 2 a 6 anos, de modo a avaliar o comportamento da incerteza relativa à caracterização histórica de recursos eólicos e analisar em que medida esta incerteza impacta no cálculo da estimativa de geração de eletricidade por um conjunto de aerogeradores hipoteticamente dispostos naquele local de interesse. Foi possível verificar que, para os dados e casos analisados, à medida que se aumentou a duração da campanha de medição anemométrica, a incerteza da caracterização histórica de recursos eólicos sofreu queda significativa; determinando, por conseguinte, redução da incerteza total que permeia a geração eólica. Ademais, a quantidade de energia estimada para o parque eólico hipotético exemplificado também decresceu, permitindo melhora na acurácia da previsão de geração e beneficiando a confiabilidade da fonte eólica no sistema elétrico brasileiro. / Driven by the energy auctions system, the energetic harnessing of wind resource in Brazil is now going through a phase of expansion in participation in the national electric energy mix. Nevertheless, the performance of power generation of in-operation wind farms was monitored and the results proved to be, on average, below what was initially entrusted to the National Grid System, indicating that the energy production estimations projected by some energy auctions winners could have been overestimated. This scenario has caused the requirements for participating in the energy auctions to be more conservative, with measures such as the adoption of the P90 on the calculation of the physical guarantee and the increase of the wind measurement campaigns time span the latter to be enforced as of 2017. The wind is a stochastic resource, hence there are uncertainties intrinsic to the Wind Resource Assessment that influence a wind farms power generation estimation and that need to be properly identified, quantified and reduced, as far as possible. In this respect, the influence of a wind measurement campaigns time span on the Wind Resource Assessment based on MCP methods an important tool in the process of characterizing the long-term wind regime was studied in order to detect the potential of enhancing the accuracy of wind power generation forecasts. For this purpose, four databases containing time series of wind speed and direction belonging to a target site were used. Firstly, nine different MCP methods were tested and compared, of which the Vertical Slice method implemented on the software Windographer outperformed all the others according to the Mean Absolute Error and Root Mean Square Error metrics. Subsequently, the databases were set to simulate campaigns with time spans varying from 2 to 6 years, in such a way to evaluate the behavior of the uncertainty in the long-term wind speed and to analyze how this uncertainty impacts the calculation of the energy production estimation of an array of wind turbines hypothetically placed on that target site. From the analyzed data and cases, it was verified that, as the wind measurement campaigns time span was increased, the uncertainty in the long-term wind speed was significantly diminished, thereby reducing the overall uncertainty that pervades the wind power harnessing. Furthermore, the energy production estimation of the exemplified hypothetical wind farm also decreased, allowing an improvement on the accuracy of the energy generation prediction and benefiting the reliability of wind power in the Brazilian electric system.

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