Sugarcane stalks contain approximately 14 to 16 percent sucrose and 12 to 14 percent bagasse with other residues (for example, tops and leaves), which are increasingly used as fuel. The sugar contents represent 2.54 gigajoules per ton and 4.65 gigajoules per ton for residues. Based on an average yield of 82.4 tons per hectare in southeast Brazil, this represents 383 gigajoules per hectare. Considering a co-generation efficiency of 69 percent, about 287 gigajoules per hectare are available per ton of sugarcane. With the progressive introduction of more efficient boilers (currently 20 to 100 kilowatt hours and up to 200 kilowatt hours), and of greater amounts of sugarcane processed, huge surpluses of electricity can be generated. A modern sugarcane plantation could generate up to 15 times more energy than it consumes. In addition, current productivity is considered low compared to its agronomic potential of up to 340 tons per hectare.