This excerpt taken from the PBR 6-K filed Nov 19, 2009.
The year-on-year improvement was due to the following factors:
Reduced energy purchase costs due to the reduction in the difference settlement price;
The greater availability of energy for trading, due to the recovery of the peg;
Increased fixed revenue from auctions, as well as higher energy exports; and
A reduction in the natural gas import/transfer cost, accompanying the behavior of international prices.
Other contributory factors included the conclusion of infrastructure projects, which facilitated gas production outflow, thereby avoiding the failure-to-supply penalties incurred in the 9M-2008.
These effects were partially offset by reduced thermal power output due to higher hydroelectric reservoir levels and lower gas sales volume.