The use of vegetable waste as fuel for the production of electricity is another of the strategies promoted to reduce the emission of greenhouse gases.

ACCIONA is present in the area of biomass with three installations, totalling 33 MW of power. In 2006 these produced a total of 241 million kilowatt hours.

The largest of the plants is a cereal straw combustion plant constructed in Sangüesa (Navarra), and is unprecedented in the South of Europe in the exploitation of this source of renewable energy. In 2006 it produced more than 200 million kilowatt hours.

ACCIONA also has plants in Talosa and Pinasa, in the provinces of Soria and Cuenca respectively, with 4 MW of power each.

The company plans to significantly promote activity in biomass. In Castilla y León it is developing three plants totalling 55 MW of power and representing a joint investment of 140 million euros. The three installations, located in Almazán (Soria), Valencia de Don Juan (León) and Briviesca (Burgos) have the participation of the Regional Energy Board (EREN) for Castilla y León.

Together, the three plants are expected to generate some 440 million kilowatt hours per annum, equivalent to the consumption of 180,000 homes, provide 300 jobs, directly or indirectly, and prevent the emission 423,000 tonnes of CO2.