Allen Gears has scored another major success in the huge and highly competitive hydropower market in Brazil.
Six identical horizontal epicyclic gearboxes will provide the vital link between turbines and generators at four new hydropower sites in Brazil, a country that uses the flow of water to provide more than 90 per cent of its national electricity.?
Significantly, Alstom Brazil's selection of Allen Gears' technology comes in the wake of three outstanding recent hydropower successes, each of which relies on Allen epicyclic gearboxes. The first of these, at Ourinhos, was completed between 2003 and 2005 and provides Alstom Brazil with a clear technical and commercial lead over its competitors.
"This is because our proven epicyclic technology gives better mechanical efficiency compared with other gearing systems," explains David Freeman, Allen Gears USA Sales Manager. "In this case, an efficiency of 99.3% translates directly to increased revenue for the power producer."
All six gearboxes for the latest Brazilian project are rated at 17.5MW and have an input speed of 147rpm and an output speed of 600rpm. The inherent flow rates of low head installations result in the use of a Kaplan type turbine with a typical turbine speed of around 150rpm.? This needs to be geared-up to typically between 600 and 750 rpm to maximise generator efficiency and cost-effectiveness.
''Gearing-up the speed of the turbine enables the size of the generator to be reduced, potentially saving millions of dollars in the cost of the generator and dam construction costs,'' adds David.
"The smaller size and 'footprint' of an epicyclic unit compared with the traditional parallel shaft design can bring very significant savings through reduced civil engineering and much less concrete to pour. By cutting the cost of the generator and of the engineering, projects can become much more financially viable through the use of our epicyclic technology."
The first four gearboxes are set for delivery from January next year to sites at Queluz, Palmeira and Retiro. Delivery of the fifth and six units to the Lavrinhas hydropower project is set for completion in August 2009.
This fourth major order from Brazil since 2002 gives great confidence for further significant hydropower success in this region during the next 12 months.