 |
|
|
|
|
|
» Eolian Energy
Aeolian energy is currently used throughout the world on a large scale. In the past decade, its evolution shows its acceptance as a source of generation, with expressive growth trends in the energy matrices in the countries where this source is used. The world's installed capacity is above 30,000 MW. Most of the projects are in Germany, Denmark, Spain, and in the United States.
In Denmark, eolian energy contributes with 12% of the total electric energy generated in the country; in northern Germany, in the Schleswig Holstein region, it is above 16%; and the European Union's goal is to capture 10% of all of its electricity from the wind by 2030.
Brazil has a high eolian potential: some 140 gigawatts, according to the Brazilian Aeolian Atlas published by CEPEL (Eletrobrás' Electric Research Center), concentrated mainly in the Northeastern coastal regions.
Eolian energy is renewable and has very low environmental impact. To generate it, there are no gas emissions, no effluent refuse, and no other natural resources, such as water, are consumed. To have an idea of soil occupation, the equipment occupies 1% of the eolian power plant’s area, while the remaining portion can be used for crops or pasture, and no trouble is caused for animals or plants. People can live as close as 400 meters to eolian plants without being disturbed by their noise. In fact, in Denmark, farmers have aerogenerators installed right next to their homes.
A major impulse for eolian energy will be the redemption of the carbon equivalent credits resulting from the production of clean energy compared to the same amount of energy produced using fossil fuels. With the ratification of the Kyoto protocol, power generation using the eolian source may be greatly benefited with the emission of carbon certificates, the values of which may be expressive, and this will contribute to improving the eolian projects' economic yield.
In January 2004, Petrobras inaugurated, at the Macau/RN oil production unit, its first eolian park with an installed power capacity of 1.8 MW (3 aerogenerators of 600 kW each). The company is developing the project for its second eolian park, which will be located in the Rio Grande region, in the state of Rio Grande do Sul, with a 4.5-MW capacity. Furthermore, it has more than 20 eolian potential measurement points in Brazil, and is undertaking studies to install other units and partnerships in PROINFA (Incentive Program for Alternative Energy) project.
The PROINFA, instituted by Law No. 10.438, dated April 26 2002 and reviewed by Law No. 10.762, dated November 11 2003, aims at diversifying the Brazilian power matrix and at searching for regional solutions using renewable power sources. The program will promote the deployment of 3,300 MW of capacity, 1,100 MW coming from eolian energy, 1,100 MW from biomass, and 1,100 MW from SHP (small hydroelectric plants).
In the past decade, aerogenerators were devices that reached a power of 250 to 500 kW, their rotors had a diameter of 50 m and their towers reached a height of 50 m. Nowadays, they are produced in industrial scale and reach 3,000 kW, with rotor diameters of 100 m and tower heights of 100 m.
The market already works with 4,500-kW prototypes, devices that are 100 m in diameter and have 120-m towers. When these machines become commercially viable, a single turbine will be able to supply some 21,000 residential consumers, equivalent to a 4,200-home district.
The quality of the energy depends basically on the type of generator that is used (asynchronous or synchronous) and on how it is adjusted. If the power grid the eolian plant is connected to is considered strong, the influence of the voltage variation caused by the aerogenerator due to wind speed variation is not greatly noticeable. On the other hand, if the grid is weak, this variation may cause great voltage fluctuations in it.
Brazil's Eolian Potential
The maps show Brazil's eolian potential in 4 different periods of the year.
The following comparative advantages take the highlight:
- Large amount of energy generated per unit;
- The area occupied by each turbine, including the access roads, is only 1% of the total area reserved for each unit, which is considered the minimum recommendable spacing. The other 99% of the area can be used for other purposes, such as planting grass, vegetables, and pasture;
- The current energy generated by a 600-kW turbine avoids, on average, the emission of 1,200 tons of CO2 per year, if the same amount of energy were generated by a diesel plant;
- The energy produced by an eolian turbine during its useful life (20 years) is eight times more than the amount of energy used to build, maintain, operate, disassemble, and fully recover it. In only three months of operation, the turbine produces an amount of energy that is equivalent to the energy used to build and operate it.
|
|
|
|
|
