Innovative Solution

water-energy harmonization, percolation, innovation, water treatment stations, hydropower plants

technical

Tractebel Energia S.A. has implemented in three of its hydropower plants an innovative solution developed by technicians of the company, which replaces Water Treatment Stations. The use of percolation water – which spills from the rocky massifs of the water intake of plants – for human consumption in the project has proved to be a simple, efficient alternative whose cost is lower than the traditional system and with little environmental impact.

The Water Treatment Stations, with high implementation and operation costs, required the use of chemical products to remove solid agents and other impurities from raw water, and required the proper elimination of solid residues. Furthermore, it was necessary to use a contractor to operate the Stations while there was a constant demand for maintenance because the equipment would deteriorate rapidly due to the intensive use of chemical products such as caustic soda.

During periodical inspections of installations, the technicians of Tractebel Energia started observing the water behavior in percolation galleries, which until then had no use at all. These galleries are excavated during plant construction in the rocky massif that surrounds the engine room and are used to alleviate the flow and drain water from the reservoir that infiltrates in the rock.

During a superficial analysis, the technicians noticed that the water that spilled inside the gallery of plants was clear and abundant. However, some tests and confirmations still needed to be performed so that the new system would be implemented.

In view of the natural quality of percolation water and the simplicity of the system, its implementation cost was only BRL 17 thousand for both Itá and Machadinho Hydropower Plants. By way of comparison, this value corresponds to three months of operation of each Water Treatment Station in said plants.

The solution has been initially implemented in the plants located in the Uruguay River basin – Itá and Machadinho HPPs, on the border between the states of Rio Grande do Sul and Santa Catarina. Later on the solution was replicated to the Salto Osório HPP, in the State of Paraná.

Leading private company of Brazil´s power generation sector, Tractebel Energia S.A. (www.tractebelenergia.com.br) currently operates in 12 Brazilian states with a generating park including 22 power plants comprising hydroelectric, thermo and complementary ones (small hydro power stations, wind farms and biomass plants), thus corresponding to about 7% of the national market supply. Out of the 22 power plants that make up the generation park of Tractebel Energia, 15 are certified according to standards NBR ISO 9001, NBR ISO 1401 and OHSAS 1801.

The concern with the development of its employees, along with an environmental awareness that is part of Tractebel Energia´s corporate culture, produces an environment leading to the development of sustainable and innovative solutions. This is confirmed through this solution, which was conceived by two employees and has already been implemented in three hydroelectric plants operated by the company.

The main goal was achieved in 2009 when the Water Treatment Stations of Itá and Machadinho HPPs had their operations interrupted.

Following the success achieved, a decision was made to appraise the implementation of the solution in other plants operated by Tractebel Energia that could also deactivate Water Treatment Stations. The following one has been Salto Osório HPP, with the deactivation of the Station in January 2011.

General objective

Replace Water Treatment Stations responsible for the production of potable water in the facilities of Itá and Machadinho Hydropower Plants with a system that uses water that percolates from the dams.

Specific objectives:

•  Preserve natural resources
• Deactivate the Water Treatment Stations of Itá and Machadinho HPPs
• Eliminate the production of solid residues resulting from water treatment
• Reduce the use of chemical products in the raw water treatment
• Reduce power consumption of the process
• Reduce costs from this process

• Elimination of chemical products consumption for water treatment since substances such as aluminum sulphate and caustic soda are no longer used
• Prevents the production of solid residues with the elimination of mud coming from the Water Treatment Station, which had high iron, aluminum, manganese and organic matter content
• Eliminates the need for transporting these residues to landfill areas located 75 km and 180 km away

• Low implementation cost – costs elimination totalizing BRL 3.7 million, taking into account their concession terms

The objective is to implement the same solution in other hydropower plants in Brazil using the same technology to reduce costs and environmental impacts in water treatment.

This solution perfectly meets the needs of water for the power plant, for use as drinking water and services water in general. Where possible and feasible the implementation of this system, we recommend its implementation, which will reduce investment costs and operation.

This solution is the result of discussion and suggestions of employees, stimulated by the company to find innovative solutions for day to day problems.

The implementation of this system eliminated or reduced operation and maintenance expenses of Water Treatment Station and the use of chemicals.
The success factor is the simplicity of the system, easy to deploy and operate at lower cost.

Main lesson learnt is to give empowerment and training for employees to be innovative.

This system was implemented in Machadinho and Ita HPPs and then was replicated to Salto Osório HPP.

Nauro Roberto Cornélio – nauro@tractebelenergia.com.br; + 55 49 3458 9009

Elinton Andre Chiaradia – elinton@tractebelenergia.com.br; + 55 49 3458 9100