Roberto Fernando da Fonseca Lyra

Análise dos padrões de vento no Estado de Alagoas

Aiming to evaluate areas with good prospects for harnessing wind power, the patterns of wind speed and direction measured at anemometric towers within the Atlas Eolico e Disseminacao da Tecnologia Eolica no Estado de Alagoas project were compared for the period from 12/2007 to 11/2008, at Alagoas State. We analyzed three distinct regions: Coast, Agreste and Sertao. The patterns with higher average wind speeds were in the Agreste regions (7.1 ± 1.2 ms-1 monthly) followed by Sertao (6.8 ± 0.9 ms- 1 monthly) and by Coast (5.3 ± 0.8 ms-1 monthly). The regularity of the wind speed and the low variability of wind direction make Alagoas be a great option for the installation of wind turbines.

Previsão do vento utilizando o modelo atmosférico WRF para o estado de Alagoas

This paper aim to analyses wind prediction over the Alagoas State (Brazil) using the WRF model. A 1-yr (August/2007 to July/2008) anemometer collected data is used to analyze wind pattern and the model predictions were statistically validated using stations located in the three State mesoregions: Backlands (Sertao), Rural (Agreste) and Coast (Litoral). The results showed that quality of WRF model prediction proved to be quite satisfactory especially in the interior of the State during the dry season. The wind predictions in the rainy season for coastal zones showed bias of 1.77 ms-1 and RMSE of 3.61 m.s-1, while in the dry season these ratios were 0.98 m.s-1 and 2.99 m.s-1, respectively. In the interior of the State, these indicators reached bias of -0.2 m.s-1 and RMSE of 2.75 m.s-1 for dry months, and bias of -0.1 m.s-1 and RMSE of 2.63 m.s-1 for rainy season. Some aspects of the WRF model must be further tested and analyzed to improve the prediction during the rainy period, especially the parameterizations of cumulus and clouds microphysics. The obtained statistical indexes were equivalent or better, in some cases, if compared to other similar studies, indicating that the WRF is a good tool for wind forecasting.

Evidência observacional das brisas do lago de Balbina (Amazonas) e seus efeitos sobre a concentração do ozônio

Local wind systems, such as sea or lake breezes, strongly affect the transport and dispersion of atmospheric trace gases. Based on its size and location, the artificial lake of Balbina in the Amazon - can be expected to give rise to a lake/forest breeze regime. During the period 2 to 28 July 2002, within the LBA/CLAIRE-2001 experiment, we have continually measured the ozone concentrations (O3) and the wind directions close to the Balbina dam. We found that there is indeed a well established breeze system, with lake breezes prevailing during mid-day (10 to 14 LT) while forest breezes prevail from the afternoon to early morning (16 to 8 LT). During the latter period radioactive cooling in the forest creates a strong local thermal contrast. The average daily ozone concentration was 8.7 ppbv, with an average of 10.6 ppbv during the day, and 3.5 ppbv at night. When local winds came from the lake, even at night, ozone concentrations were greater compared to breezes coming from the forest.

Confiabilidade nas estimativas do regime do vento fornecidas pelo brams no estado de Alagoas: influência do aninhamento e da resolução horizontal de grades

Os resultados do estudo comparativo entre os dados observados em duas torres anemometricas instaladas no estado de Alagoas, com estimativas de vento produzidas em simulacoes numericas realizadas com o modelo de mesoescala BRAMS, sao apresentados e discutidos com o intuito de investigar a influencia do refinamento da resolucao horizontal e do aninhamento de grades na confiabilidade das estimativas de vento. As torres estavam instaladas em regioes de caracteristicas distintas do ponto de vista ambiental e climatologico. Analises estatisticas foram realizadas para avaliar o desempenho do modelo no que se refere a capacidade de fornecer estimativas de vento que reproduzam a evolucao temporal, o ciclo medio diario e a distribuicao de frequencia do vento observado nas duas localidades. O estudo foi realizado para as duas estacoes sazonais caracteristicas da regiao: estacao chuvosa (Maio/2008) e seca (Novembro/2008). Os resultados mostraram que houve um aumento na confiabilidade das estimativas da velocidade do vento quando a resolucao horizontal passou de 8 km para 2 km. O ganho em confiabilidade foi mais significativo em Girau do Ponciano (GRP) localizada no interior do estado e que sofre menor influencia do fenomeno de brisa maritima. O aumento da resolucao horizontal para valores abaixo de 2 km nao produziu reducao importante dos desvios observados na estimativa da velocidade do vento pelo modelo na configuracao adotada neste estudo. Os resultados demonstram a importância da aquisicao de dados de campo para a investigacao da confiabilidade, e ajuste das configuracoes e parametrizacoes inseridas em modelos numericos, utilizados para estimar ou preReliability evaluation of wind regime estimates provided by the brams model for alagoas state (brazilian northeastern region): influence of nesting and horizontal resolution gridsver a disponibilidade de energia eolica em uma regiao especifica.

Wind Power in Girau do Ponciano, Alagoas, Brazil Using Anemometric Data and Microscale Modeling

The wind potential in the Agreste region of Northeastern Brazil has important features for energy exploration, but, stills unexplored. This work analyzes 3.1 yrs anemometer tower measurements in the Girau do Ponciano, Alagoas state. The observational data was recorded from October 2007 to October 2010. Three periods were defined to constrain the seasonal wind patterns: Annual, Dry (October-January) and Wet (May-August). Hourly and monthly series showed the average wind speed was higher than 7 m s, reaching 8.5 m s during the dry season. Further, the wind direction was also favorable with less variability, concentrated between NE and SE. During nighttime the wind speed 10 m s were more frequent. The Weibull fit is more distributed (concentrated) during the dry (wet) season close to 8 m s (7 m s). The AEP (Cf) parameter estimated by the WAsP model varied between 3 to 10 GWh (35% to 65%). Nevertheless, Girau do Ponciano domain was positioned nearby two highways and close to an electrical substation in the Arapiraca city. Other geographic conditions (topography inclination < 15°, the absence of obstacles, and low vegetation) are also favorable to future wind farm installation in this area.

STUDY OF THE WIND ENERGY PRODUCTION WITH MEASUREMENTS WIND SPEED AND DIRECTION FROM CRAÍBAS/AL STATION AND SIMULATION WITH WASP MODEL

Wind energy is seen as one of the promising generation of electricity, as a source of cheap and renewable, is benefit to reduce the environmental impacts of the dam. Along with the hydroelectric networks, the energy produced by the wind will help to increase power generation capacity in the country. That from speed data and direction municipality Wind Craibas in the corresponding period 2014 - 2015, estimated the wind potential of the region. The tool used in the treatment of the collected data was the Wasp, making simulations of three different levels of measurement, producing a fictitious wind farm with powerful wind turbine. With the model, WASP helps estimate the probability distribution of Weibull and scale parameters A and K. he predominant wind direction is southeast and the best wind power and intensity density levels took place in 70m and 100m high , with about 201 W / m² and 243 W / m² respectively. But when evalua ted the inclusion of fictitious wind farm, the best use happened at 100m tall with production around 73.039 GWh , which can be attributed this improvement to increased efficiency of the wind turbine used in the simulation.

PROGNOSIS OF THE WIND FOR ALAGOAS STATE USING WRF MODEL: STUDY OF THE UPDATE TOPOGRAPHY, LAND USE AND FRICTION VELOCITY

This paper aims to make an evaluative study of the updates topography, land use and friction velocity performed in the atmospheric WRF model, and prove its efficiency in simulating the wind speed and direction patterns using measurements of anemometric station Maragogi/AL, during the period from August/2007 to July/2008, focusing to May/2008 showed low correlation coefficient indices. The changes resulted in improvements made in the correlation coefficient for the wind speed of 0.15 to 0.61, however it is not perceived improvement to the wind direction. Highlighted the fact that the topography and friction velocity were the variables that most influenced the simulations, however there was little difference between the default condition the update condition for land use. The average speed for the city of Maragogi/AL was 5,27m/s predominant direction of South East wind. Generally noticed an improvement in the simulations when implemented updates in the model.

WIND VELOCITY FORECAST USING WRF MODEL ON THE CENTRAL REGION OF ALAGOAS STATE (BRAZIL)

The PVPN project (Previsao do Vento em Parques Eolicos no Nordeste Brasileiro “Wind forecast for wind farms in the Brazilian Northeast”) has been made aiming to developing a methodology for the prediction of short and medium-term wind energy in wind farms, proper Brazilian Northeast. This paper presents results from an intensive campaign, which, wind velocity and micrometeorological measurements including turbulence are made. Estimates made by the WRF model for the wind velocity were compared with friction velocity and the fluxes (sensible heat and latent heat). The results showed that the model represented well the daily cycles of the four variables with correlation coefficients between 0.79 and 0.94. The estimation of the wind velocity were very good with a difference of only 10.55%. The estimate of the remaining variables was bad to reasonable.

ANÁLISE DO POTENCIAL EÓLICO NA REGIÃO METROPOLITANA DE NATAL – RN

This work aimed to make a wind potential analysis in the metropolitan region of Natal in the State of Rio Grande do Norte, thus obtaining the characteristic of wind power and wind power generation using the weibull distribution.

CASOS DE BRISAS VALE/MONTANHA NO INTERIOR ALAGOANO NA ESTAÇÃO DO VERÃO

O objetivo foi avaliar os casos de brisas Vale/ montanha entre 2 regioes distintas, agreste e sertao alagoano. A serie de medidas anemometricas utilizada foi dos meses de Janeiro, fevereiro e Desembro de 2008. Verificou-se um maior numero de caso de brisa em Palmeira dos Indios (agreste), com intensidade do vento maior que em Agua Branca (sertao). As brisas sao frequentes de madrugada e no horario de transicao da (00:00 a 11:50).