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The force of the current

Hydraulic turbine takes electricity to isolated riverine communities

MIGUEL BOYAYANHydrokinetic turbine, above, installed and at work in the Corrente river, in Bahia MIGUEL BOYAYAN

A turbine of small proportions, capable of transforming the water of the rivers that cut through the riverside communities in electricity is at work in an isolated village in the municipality of Correntina, in Bahia. This mini-power station has the capacity to generate up to 1 kilowatt (kW), at alternating currents between 110 and 220 volts, enough to supply a house with a few household appliances and a water pump. It may not seem much. But for localities distant from the transmission lines and that cannot count on dams and reservoirs for the generation of electricity, this makes the difference, because it makes it possible to light up schools, medical posts and small groups of houses.The proposal for implementing alternative solutions for the efficient use of electricity in regions where this is a scarce or nonexistent boon is the objective of Hidrocinética Engenharia, of Brasilia, the federal capital, the company responsible for the turbine. Installed on the campus of the University of Brasilia (UnB), the company is part of the Company Incubating Program of the Technological Development Center (CDT-UnB).

Hidrocinética was created six months ago, but its founding partners, engineers Rudi Henri van Els and Clóvis de Oliveira Campos, have been researching an innovative model for generating electricity since 1995, with the support of the university’s Mechanical Engineering Department. Rudi and Clóvis used to be researchers and substitute professors at the UnB.The idea of building a model of a turbine driven by the force of river currents came up the beginning of the 1990s, when physician Edgard van den Beusch, a former UnB professor, asked the university’s Mechanical Engineering Department (DEM) for a solution for supplying electricity to a health post located in a village on the banks of the Corrente river, in the municipality of Correntina.

Social demand
The request resulted in the Hydrokinetic Turbine Project, supported by engineers from the hydraulic, mechanical and electrical areas. The author of the first calculations that made the equipment viable was Professor Lúcio Salomon, of the DEM.”The origin of the project is actually in a social demand. The machine is more than an invention, it is a social technology”, Rudi explains. The first prototype of the hydraulic turbine became ready in 1995. As soon as it was installed, the health post coordinated by Beusch started to be able to rely on enough electricity to work the water pumps, the lighting and domestic appliances.

The quantity of electricity generated from the turbine is connected with the speed of the waters and the depth of the river. For the equipment to work, the speed of the current must be at least 1.5 meters a second (m/s) and the depth of the river has to be at least 1 meter. With these prerequisites, it is possible to get 400 kilowatts hour (kW/h) per month, but, under better conditions, the engineers point out that it is possible to achieve a production of electricity in the order of 3,000 kW/h per month, which means the average consumption of ten modest houses.Before installing the equipment in a locality, the researchers carry out studies that involve topographical data, mapping by satellite of the areas that have hydraulic potential, and identifying the profile of the users. The geographical conditions of the banks of the river indicate the most appropriate place for setting up the machine’s support. Depending on the hydrographic specifications, the model of the turbine can be adapted.

Just as important as the identification of the local hydrography and geography is the field survey carried out of the population that will be served. The visit to the community makes it possible to diagnose the social privations and needs of the region. “Following a democratic process of participative management, the community meets to define where it wants to apply the output of electricity for the common good, because the turbine does not manage to generate sufficient energy to attend to all the houses of a village”, explains Alexandre Maduro, who is a member of the team. After the installation of the equipment, the researchers teach the inhabitants how to carry out the maintenance and operation of the equipment.

The first public and official recognition of the invention dates back to 1997. That was when researchers from the DEM at the UnB were given the Young Scientist Award by the Science and Technology Institute of the government of the Federal District. In 2000, after almost ten years of work carried out with their own resources, they arrived at a more improved version of the turbine, both as far as the architecture and the engineering of the machine are concerned, and in the reduction of production costs. The second prototype was also installed in the municipality Correntina, on the banks of the Meio river.

Interdisciplinary nucleus
With the sanction of the model of the hydrokinetic turbine and the crisis in the electricity sector in Brazil, better known as the “blackout crisis”, in 2001, the researchers managed to raise funds and support, which made it possible for the experiments to evolve. In the following year, Rudi and Clóvis received subsidies from funding agencies to improve the process for producing the turbine, and they set up the company. Amongst these entities are the National Science and Technology Development Fund (FNDCT/CT-Energ) and the Financier of Studies and Projects (Finep). The project also enjoys technical advice from the Scientific and Technological Enterprises Foundation (Finatec) of the UnB and the CDT.The original group, made up only of engineers, was expanded and turned into an interdisciplinary nucleus, which also includes administrators and geographers, whose principal mission is to perfect the original model of the turbine.At the moment, a third version of the machine is being constructed, at the request of the National Institute for Amazonian Research (Inpa), in Manaus in the state of Amazonas. Adapted in accordance with the social and hydrographic peculiarities of the region, the turbine should be installed by 2004 in one of the riverside communities of the Amazon river. “The modifications in the machine are necessary to the extent that there are different behaviors in the currents of the rivers and differentiated profiles of the topography of their banks”, Rudi emphasizes.

In the assessment of the company’s partners, the sales price of the hydrokinetic turbine, R$ 10,000, is an obstacle to its acquisition by poor communities. That is why they recognize that the current challenge for the business is not centered on restriction by the market, technological improvement of the equipment, or reduction in production costs.For Rudi and Clóvis, what is fundamental is to stir the third sector (nongovernmental organizations) and, above all, state and municipal governments, to subsidize the access of poor communities to the turbine, because, according to data from the Brazilian Institute of Geography and Statistics (IBGE) of 2000, about 5.2% of Brazilian households do not have electricity. This technology has already shown that it even has potential for boosting economic growth and social development of these populations. Not to mention that putting the force of naturally moving water to good use for generating electricity avoids interference with the environment and radical changes in the way of life of the riverine communities.