MEXICO CITY — Energy can be harnessed from the most unexpected places. In Mexico, it now even comes from trash.
Recently, an enormous landfill in the east of Mexico City was sealed over and converted into a retail park, and underneath it, a unique system turns mountains of trash into megawatts of electricity.
Neza Uno was a 350-acre dump overflowing with twenty million tons of garbage, severely contaminating the air and water basins in this part of the city for over thirty years, where today over a million people live. Now transformed, the site is a modern complex bustling with life that houses a mall, hospitals, government offices and sports grounds.
Ciudad Jardín, the Garden City, is the result of a five-year, 200-million dollar collaboration between the local authorities and private developers. From early on, a biogas collection system was envisioned to tap the potential energy latent in the millions of tons of organic garbage. Construction firm GUCAHE, whose founder Heberto Guzman was the visionary behind the project, hired engineer Jorge Sanchez to devise and install the system.
His design involved laying three miles of pipes underground to collect the biogas emitted by the trash - basically carbon dioxide and methane, the two gases responsible for global warming. The gas is fed into the biogas plant where it is currently being incinerated, but in mid-2011, the generators that convert biogas into electricity will be installed, and the cycle of regeneration will be complete.
According to Sanchez’s calculations the site will be able to produce up to three megawatts of electricity for ten years, enough to power the entire park and service parts of the local community, where the power grid is severely lacking. The award-winning project, one of the first of its kind in the world, is already being adopted as a model for landfill regeneration in other parts of Mexico. As Jorge Sanchez says, “the days of simply covering a landfill with earth and abandonning it are over.”