Green energy

Waste and biomass can make a significant contribution to clean energy production. Experts calculate that within ten years waste could provide 8% of all energy consumed in Spain.

Capture of biogas generated in landfill sites can make a contribution to reducing methane emissions, a gas that makes a large contribution to the greenhouse effect, and to creating value through the transformation of these emissions into:

  • Electricity through combustion engines.

  • Thermal energy from the same combustion engines or from direct combustion of the captured biogas in boilers; and

  • An energy source for other external production processes.

Since 2004, Cespa has been participating in the Microphilox project (Energy recovery from landfill biogas through microturbines and biological treatment to remove the hydrogen sulphide and siloxanes contained in biogas). In 2005, Cespa installed the first biogas microturbine in Spain. This project, which will end in 2009, has received funding from the European Commission through the LIFE programme. It has the participation, as a partner, of the Austrian Profactor technology centre and the Department of Chemical Engineering of the Institut Quìmic de Sarrià (IQS).

During the year, there was an increase in the quantity of biogas captured in Cespa landfill sites in Spain, which has increased from 30.66% in 2006 to 35% in 2007. This is due to the construction of new wells (Sta. María de Palautordera), the installation of new degasifying plants (La Vega), the sealing of several cells forcing their degasification (Larrabetzu and Alcázar de San Juan) and the opening of a new facility in Toledo. In Portugal, the opposite has occurred. The amount of biogas captured was reduced (from 4.30% in 2006 to 0.13% in 2007) which led to a rise in emissions. The reduction in the quantity of biogas captured is due to the annual availability of the combustion equipment installed being lower.

 Electricity produced by biogas recovery

Biogas capture has avoided 514,090 Teq of CO2 emissions and has reduced methane emissions by 5%. At present, the proportion of torch burned methane recovered as energy with respect to that potentially emitted is 35%.

Cespa has 16 landfill sites with biogas recovery, 12 of which generate energy: 8 produce electricity and 4 thermal energy. During 2007, biogas recovery increased electricity generation by 10.5% to 279,841 GJ of electricity. On the other hand, the generation of thermal energy through biogas recovery was reduced by 7% to 175,134GJ

Hazardous waste incineration has produced electricity by cogeneration of 61,050 GJ, 7.60% less than in 2006.