The impacts of global climate changes on the wind power density in Brazil Enio B. Pereira * , Fernando R. Martins, Marcelo P. Pes, Eliude I. da Cruz Segundo, André de A. Lyra National Institute for Space Science e Earth System Science Centre, P.O. Box 515,12227-010 São José dos Campos SP, Brazil article info Article history: Available online 18 February 2012 Keywords: Wind potential Wind energy Climate changes Wind scenarios abstract Brazil’s wind energy production has escalated up recently. However, the long-term wind projects do not include the yet unknown impacts of climate changes on wind power. This work is an assessment of these impacts by applying forecasts of a climate model and trend analysis over climatological time series from selected ground sites. Findings indicate a favourable scenario for wind power exploitation in Brazil on the long run. Ó 2012 Elsevier Ltd. All rights reserved. 1. Introduction Brazil’s wind energy production has escalated up from 22 MW in 2003 to 602 MW in 2009 thanks to the Proinfa (Program for Incen- tive of Alternative Electric Energy Sources), which is a government program to encourage the use of wind power, biomass, and small hydroelectric power. An additional 256.4 MW is now under construction. Recently 71 additional projects have been approved as a result of the first wind-only bidding round for energy supply in Brazil of December 2009. The contracts, totalling 1800 MW, will start up in July 2012 with a supply period of for 20 years. Developing wind power in Brazil will help the country to meet its strategic objectives of enhancing energy security, creating more jobs and, at the same time, reducing the country’s energy-related greenhouse gas emis- sions. The potential inland wind power resources in Brazil could reach more than 145,000 MW. In spite of this, the long-term growth of the national wind capacity depends not only on a more compet- itive price for this energy (today at US$ 84.8 MWh) but also on the sustainable domestic development of this technology. Furthermore, since wind contracts are long term, the yet unknown impacts of climate changes on the wind power may possibly cast doubts and uncertainties on the revenues of investments in this area. Eichelbergr et al., 2008 [1] analysed the surface wind fields from a 14-member ensemble of GCM simulations to evaluate the impact of global climate change on near-surface wind speeds using the A1 and B2 scenarios from the IPCC. The models revealed globally the regions with the percentage of models showing increased annual-mean wind speed values in 2050. For North America, most models predicted increases in annual mean wind speed of up to 0.2 m/s on a broad North-South strip along the Eastern part of the continent, including the Yucatan peninsula for the same period. The rest of the continent will see very little change, or very small decreases. According to these authors, the forecasted wind speed differences are large enough to affect the prof- itability of existing and future wind projects in this region. A study for the US [2] has pointed out that the effect of climate change will handicap the nascent wind industry in the US by slowing the winds. Pryor et al., 2009 [3], presented signs of overwhelming dominance of trends toward declining values of the 50th and 90th percentile and annual mean wind speeds based on two observational data sets, which is also the case for simulations conducted using MM5 with NCEP-2 boundary conditions. For the case of Brazil, a previous work [4] indi- cate that the wind potential in Brazil will be benefited by the expected climate changes of the next century as a result to of GCM models outputs using the IPCC A2 and B2 scenarios. Their results indicate increasing wind speed of up to 20% up to the year of 2100, particularly in the north and coastal northeast part of the country, and a strong decline in wind speeds in a large area located in the western Amazonian region. This work intent to go deeper into this issue by refining the analysis of the impacts of the global climatic changes in the wind energy potentials in Brazil. 2. Methodology As part of this study, we employed observational data time series from selected national weather stations between 1960 and 2007 to investigate for trends in wind speed. Two target areas were selected on basis of their greater wind energy potential in Brazil and their largest number of wind projects, the Northeast and the South. We first applied a quality-control data screening process to available sites. Only 15 out of the 41 available ground sites were selected based on the continuity of the data acquisition and data quality control. Then we applied the Kendall trend test at 95% confidence level on the selected ground data. * Corresponding author. E-mail address: enio.pereira@inpe.br (E.B. Pereira). Contents lists available at SciVerse ScienceDirect Renewable Energy journal homepage: www.elsevier.com/locate/renene 0960-1481/$ e see front matter Ó 2012 Elsevier Ltd. All rights reserved. doi:10.1016/j.renene.2012.01.053 Renewable Energy 49 (2013) 107e110