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The power of the wind

Brazil's wind power potential drives research about the development of small generators

GABRIEL AMARALIn Osório, Rio Grande do Sul, a set of three wind farms produces 150 megawattsGABRIEL AMARAL

Windmills some 110 meters high transform into power the trade winds that blow constantly, the year round, on the coastal and inner-state areas in Brazil’s northeast, guaranteeing productivity far greater than the global average at the region’s wind farms. “The wind farms in Pernambuco, Ceará and Rio Grande do Norte produce far more than those of Europe, China or the United States”, says the aeronautical engineer Odilon Camargo, one of the owners of the firm Camargo Schubert, headquartered in Curitiba, Paraná state. This company produced the atlas of Brazil’s wind power potential, released in 2001 by the Ministry of Mining and Energy and the company Eletrobrás. The atlas estimated Brazil’s wind power potential at 143 gigawatts or 10 times the capacity of the Itaipu hydroelectric power station. “The estimated potential back then was already greater than anything that we now have in terms of power generation, which is of the order of 100 gigawatts”, says Camargo, who before turning into an entrepreneur was a researcher at CTA, the Aerospace Technology Centera at ITA, the Aeronautics Technology Institute, in the city of São José dos Campos, in inner-state São Paulo.

These exceptional winds, coupled with large-scale projects in areas with a low population and the global credit crises of 2009, which caused the supply of machines to exceed demand, led domestic firms and some multinationals to invest in the promising Brazilian market. The result is that the average price of wind power dropped considerably in the two renewable power auctions held by ANEEL, the National Electric Energy Agency, in December 2009 and August 2010, making this energy highly competitive. In December of last year, when 1,808 megawatts (MW) were put under contract for delivery by July 2012, a megawatt-hour cost R$148.30. By August, with 70 new mills on order, totaling 2,047 MW for delivery in October of 2013 (a capacity equaling one and a half times that of the Angra 2 nuclear power station), the megawatt-hour fell to R$130.86, a far lower price than that of the power stations that burn sugarcane bagasse (R$144.20) and of the small hydroelectric power stations (R$141.93).

Alternative power
An article in the Business section of the daily O Estado de São Paulo published on October 25 explains that the sector’s effervescence is a recent phenomenon. “It has been going on for just over a year. Previously, the price of wind-generated power wasn’t practicable in relation to the Brazilian reality. However, the winds have changed and the projects are no longer just part of the ideology of environmentalists, having turned instead into one of the country’s power supply alternatives”. This change brought in its wake companies from all over the world, such as the Argentine firm Impsa and the American enterprise General Electric, which are already producing. The competition for the Brazilian market also includes the Spanish firm Gamesa, the Indian firm Suzlon, the Danish firm Vestas and the German firm Siemens, besides Alstom, a French concern. Wobben, headquartered in the city of Sorocaba, is a pioneer in Brazil. Using the technology of the German enterprise Enercon, it continues to be among the leaders in our market.

016_Eolica_177-01Though Brazil has the largest complex of wind farms in Latin America and its current installed capacity of 835 MW increased 15-fold in the last 10 years, wind power still accounts for less than 1 percent of the power produced in the country. In the ranking of wind power producing countries, the United States holds first place, with 35 gigawatts (GW), or 35 thousand MW, of installed capacity. Then China, with 26 GW, and Germany, with 25.8 GW, according to WWEA (the World Wind Energy Association). Whereas multinationals control the supply of equipment for the projects that have won the bids and account for the greatest investment in the country, Brazilian universities and research centers are focusing on developing wind generators (pieces of equipment that form a wind turbine comprising blades normally made out of fiberglass plus an electric generator) that are small and suitable for isolated communities, farms or areas lacking access to conventional energy. They are following in the footsteps of the aeronautical engineer Bento Koike, from the firm Tecsis, in the city of Sorocaba, inner-state São Paulo, who also used to work for CTA. When he left, he started developing his own technology for making wind generator blades, and they have become a market success. His company has made to order as much as 7 thousand blades per year, ranging from 40 to 50 meters in length, and it has supply contracts with GE and other important manufacturers in the global wind generator market.

Small players in the market
One of the projects conducted by small companies and initiated in 2003 by Eletrovento, which at the time was headquartered at the Incubator of Technology Companies at the State University of Campinas (Unicamp) resulted in two low-power wind generators, one of 0.5 kW and the other of 2 kW. Both are ready for marketing. Wind generators, the machines that transform the kinetic energy of winds into electric energy, have sensors that identify the direction and strength of the wind, then adjust themselves to get the most out of each moment.

The most popular models are the horizontal ones with three blades, because they are more energy efficient, thanks to the better distribution of the tensions in relation to wind direction changes. The power obtained can be transferred directly to the conventional power grid or it can be used in isolated systems. Coordinated by the electronic engineer Cassiano Nucci Paes Cruz, the project supported by FAPESP via its Pipe system (Innovative Research in Small Companies) aimed first at developing a wind generator with an installed capacity of 5 kW.

RENATO DE AGUIARFormosa beach, in Camocim, in CearáRENATO DE AGUIAR

“Designed with efficiency to spare, it has become a 7kW commercial wind generator, enough to meet the power needs of seven average homes”, says Cruz. During the course of the project, the two other models, that provide 0.5 kW and 2 kW, we developed. They will be the first to be sold by Eletrovento – which, as of February of this year, came under the control of the firm Everest, from the town of Mairinque, inner-state São Paulo – along with the technology that Cruz developed jointly with the engineer Rubens Luciano. “The technology ranges from building the fiberglass blades to the electronic control that adjusts the machine, which can adapt not only to the huge wind variations but also to the electricity charge”, says the researcher.

The amount of power generated depends on the wind currents at the installation site. “Given an average wind, with a speed of 6 meters per second or 22 kilometers an hour, the 0.5 kilowatt wind generator can produce about 60 kWh a month”, says Carlos Pascoal Fernandes, the operating director of Eletrovento. The generated energy can power a refrigerator, TV set, parabolic antenna, a few lamps and a computer. In other words, it is enough for a small house with only a few people living in it. For comparison purposes, the average Brazilian household consumes 100 to 150 kWh a month. “However, with the 2 kilowatts generator and the same amount of wind one can produce 250 kWh a month”. This results in savings in the order of R$290.00 a month in one’s energy bill. The sales price for the 0.5 kW equipment, including the tower, battery and generator, without transportation and installation costs, is around R$17 thousand and, for the 2 kW model, R$30 thousand.

Similar systems
Another company established in São Paulo state, Dynamis, is also working on the development of a medium-sized wind generator, of about 100 kW, with the support of FAPESP via its Pipe program and of CNPq, the National Council for Scientific and Technological Development. “In 2003, we carried out prior studies along with ITA for the development of wind generators”, says the aeronautical engineer Luciano Tanz who worked for Embraer prior to becoming an entrepreneur. The studies formed the basis of a project that the company started in 2006. “The wind generator that we’re developing is about 22 meters in diameter, enough to keep a small industry, a large farm or even a village going”, says Tanz. The company expects to have a prototype in operation by 2012. The choice of 100 kW generation is strategic, according to the researcher. “The wind generators with less than 50kW power cannot compete with the cost of the energy that’s available in the market”, says Tanz. “The 100 kW kind have more room in which to compete”. For the development of the wind generator, the company turned to the experience gained making a free-fall simulator, a wind tunnel that generates a high-speed flow that can balance the weight of some people, a project initiated in 2002 with Pipe aid. “The two technologies employ similar systems”, says Tanz.

“The global market for small wind generators has been expanding and posted a 53 percent growth rate relative to 2007 and a 40 megawatts generation capacity in 2008”, says professor Jorge Villar Alé, coordinator of the Wind Power Center (CE-Eolica) of the Pontifical Catholic University of Rio Grande do Sul (PUC-RS). The 220 manufacturers spread throughout the world sold about 19 thousand units in 2008. “One of the main things standing in the way of the aid that our center can offer to small wind generator producers is that the resources of such firms are insufficient to invest in conducting the trials that the international market standards require”, says Alé. “When companies start getting government incentives to make their wind generators, they’ll be able to increase their research investments in order to develop products of the best possible quality”. As an example, the professor mentions Spain’s Minieolica project, which received – 13 million from the government for wind generator R&D. “The project involves 30 institutions, including public and private organizations, research centers and universities, which are dedicated to increasing the national use of small wind generators linked to the main grid or as isolated systems”, says Alé.

EDUARDO CESARSmall wind generator made by EletroventoEDUARDO CESAR

Cyclical trials
Wind assessments are among the projects currently developed by CE-Eolica, including taking measurements with meteorological towers, statistical treatment of the data obtained, determining the wind potential, and the best applications for it. One of the projects, which will take five years, is being conducted jointly by the Federal University of Pernambuco and the Polytechnic School of the University of São Paulo. It involves anemometry (the science of measuring wind speed) studies and small wind generators. In another study, a special set-up was developed to conduct cyclical tests with generator blades as much as 3 meters long, corresponding to 5 kW of power. The center entered into a partnering agreement with the company Enersud, headquartered in Rio de Janeiro, to evaluate the first blades made by this enterprise.

Besides blades, Enersud has developed electronic equipment that allows one to install wind turbines in the network directly, with no batteries, this being the outcome of an agreement entered into by the company, the Federal University of Ceará, and Finep (the Studies and Projects Finance Agency). The Federal University of Santa Catarina (UFSC), along with the Santa Catarina firms Milano, from the town of Criciúma, and Weg, from the town of Jaraguá do Sul, developed a 15 kW wind generator for small communities that was named Ventus. A prototype of the wind tower has been installed in a site of the Rincão resort area, in the Santa Catarina state municipality of Içara, since 2009. It can supply power for up to 30 homes with average consumption of 70kWh a month. CE-Eólica is also studying wind generator models with a vertical axis, which, as a result of their architecture, can be used in urban areas, on the top of buildings. “We have made and tested several vertical axis prototypes”, says Alé.

At present, there are 46 wind farms in operation – 38 in the Northeast and 8 in the South. Their installed capacity totals 835 MW. The greatest individual producer, the Formosa beach wind farm in the town of Camocim, in Ceará state, accounts for 104 MW. In the area of Osório, 100 kilometers away from Porto Alegre, in Rio Grande do Sul state, the winds farms of Osório, Índios and Sangradouro have a total installed capacity of 150 MW. The power generated jointly by these three would be enough to meet half the power consumption needs of the city of Porto Alegre, which in 2009 had almost 1.5 million inhabitants.

Today, we know that the potential estimated in the Atlas eólico [Wind Atlas] of 2001 is far greater than the forecast 143 GW. This is the case because, to work out this figure, the only areas taken into account were those with winds stronger than 7 meters per second at a height of 50 meters – parameters that at that time were regarded as the minimum necessary for a project to be technically attractive. “Of all the mapped areas, only 20 percent were considered usable, because of environmental, land ownership or topographic problems”, says Camargo. Fifty meters were then the average height of the wind power generators. Today, they are as much as 80, 100 or 110 meters high. “When the height increases, the potential also rises, because there’s more wind”. According to the criteria employed before, just the South of Brazil might generate 22.8 GW. “But the states of Rio Grande do Sul and Santa Catarina, in terms of area, are greater than Germany, which already has virtually 26 GW installed and is still growing”, says Camargo. As both have similar winds, we know that the potential of the South of Brazil is far greater than initially forecast. Inner-state Bahia, near the São Francisco river region, as well as other parts of the Northeast of the country are also promising for wind power enterprises. However, there is usable potential throughout Brazil.

Germany now has wind power from installed capacity equal to twice the Itaipu hydroelectric power station. “There, the interest in this source of energy arose after the general panic caused by the Chernobyl nuclear accident in the 1980s”, says Camargo. In Brazil, as a result of power rationing in 2001 due to the small amount of water at the hydroelectric power stations, the government created in 2002 the Alternative Energy Incentive Program (Proinfa), which drives the development of the use of biomass for power generation, small hydroelectric power stations and wind power. The first time the government bought a substantial volume of power via Proinfa was in 2005 (1,453 MW). After this, via the Finep Subvention Program, the federal government released two public bids that also involved projects in the energy area. The first of these bids, released in 2007, drew only two wind power projects. By 2009, this figure had increased to 16, with proposals ranging from the development of electrical and electronic equipment connected with producing wind power, presented by Weg, from Santa Catarina state, to the development of towers by Seccional Brasil, a firm headquartered in Paraná state, and the production of small wind generators, by Clamper, from Minas Gerais state.

SIEMENS PRESSEBILDTurbines installed on the high seas in DenmarkSIEMENS PRESSEBILD

Complementary energy
As Brazil’s new water reservoirs are far from the main consumer markets, experts regard wind generators as a complement to the hydroelectric power stations. “The two hydroelectric power stations, Santo Antonio and Girau, which are being built on the Madeira river, will jointly produce 6,600 MW of power, but as they have virtually no reservoir, the power generated at the times when the river is flooding or when it is ebbing will be vastly different”, says Pedro Pirelli, the executive director of Abeeólica, the Brazilian Wind Power Association, which congregates 70 companies in the generating chain. “The rain regime in the Amazon Region, which is the source of full rivers, and the wind system of the Northeast are complementary”. This is so because during droughts, when the reservoirs of the power stations are at their lowest, the winds in the Northeast are at their peak in terms of incidence and strength.

016_Eolica_177-02In an article published in Proceedings of the National Academy of Sciences (PNAS) in 2009, Harvard researchers estimated that the wind generation potential was 40 times greater than the current global production of electricity. “The research indicates that Brazil has wind power potential equal to 25 times its current generation capacity”, says Alé. This calculation, however, disregards any social, economic or environmental impact. This is a point that must be taken into account before a wind farm is set up, to avoid what happened in Ceará in 2009, when the Federal Public Prosecution Service denounced several social and environmental problems, such as the devastation of dunes, the filling of lagoons, the impact on aquifers, the destruction of homes, and  conflicts with fishing communities. “All possible environmental effects must be studied before the wind farms are erected”, says Alé. Colliding birds and the death of bats, the effect of the noise of the machines and the effect of their shadows and possible electromagnetic interference have been widely studied by wind power experts.

“One of the problems in Germany and other places, where there are wind farms near residential areas, is the shadow of the rotating blades, which generates a glare effect on some of the windows of the homes, bothering inhabitants”, says Camargo. The solution pointed out by the engineer is using a sensor that switches the machine off at times of the day when this phenomenon is more likely to occur. “The problem is easy to solve”, he says. As for collisions with birds, Camargo says that previously the machines were small, which allowed them to turn very fast, which in turn got in the way of the birds. Today, even at their top speed, the blades are quite visible. “There was a great reduction of the angular speed and the machines are at least 40 meters above the ground”.

Low impact
The Global Wind Energy Council (GWEC) and Greenpeace have released a joint survey showing that wind power should fulfill about 12 percent of global demand for power in 2020, reaching some 22 percent by 2030. According to this study, this source will be strategic for cutting down the emissions of greenhouse gases going forward. There is so much interest in this low-impact, renewable type of energy that Google, the giant Internet search engine, announced in October that it planned to invest in a US$5 billion project for installing a 563 km power transmission line. This will link the wind farms built along the east coast of the United States. Transmission lines are also one of the Brazilian concerns, even in relation to the wind farms built on dry ground or near the coast. So much so that Abeeólica plans to deliver to the federal government, by the end of this year, a study proposing the construction of a major transmission line, almost 1,000 kilometers long, solely for wind power. “This line would start at Pau Ferro, in Pernambuco state, run through the states of Paraíba, Rio Grande do Norte and Ceará and end in São Luís, in Maranhão state”, says Pirelli. Building this line will require some R$800 million. “It will complement the conventional grid and create substations in places that are currently overloaded”. The mega-line, as it is being nicknamed, would also reduce the cost of power, by reducing the distance between the generating areas and the transmission lines.

The projects
Development of a national 5 kW wind generator (nº 2002/08008-6 ); Type Program for Technological Innovation in Small Companies; Coordinator Cassiano Nucci Paes Cruz – Eletrovento; Investment R$ 79,681.00 (FAPESP)
2. Medium sized wind generation with continuously variable transmission (nº 2005/04435-5); Type Program for Technological Innovation in Small Companies; Coordinators Luciano Tanz – Dynamis; Investment R$181,596.05 (FAPESP)

Scientific article
LU, X. et al. Global potencial for wind-generated electricity. PNAS. v. 106, n. 27, p. 10.933-38. 22 jun. 2009.