We have become the first auto company in Thailand to receive the ISO 50001 energy efficiency certification. In the process of achieving the certification, we estimate that greenhouse gases have been reduced by more than 4,000 tons at our car and truck assembly facility in Rayong. These savings were the result of nearly $500,000 in energy-saving investments that included upgraded office and external lighting, warehouse skylights, a waste heat recovery system and a more efficient air compressor. In addition to achieving the stringent ISO certification, the team in Rayong also has achieved landfill-free status.
Though our plant in Zaragoza is already home to the world's third-largest rooftop solar installation, employees are committed to achieving even further energy efficiencies. They embrace a belief that any idea, however small or big, is vital to energy reduction. In fact, there is a committee dedicated to confronting energy-saving opportunities that are significant, yet difficult to implement. Their dedication paid off in 2011 with a 14.5 percent reduction in energy consumption. The zest for energy conservation also extends beyond the plant. A local initiative that works against climate change at the household level counts 50 percent of its participants as workers for GM Spain.
The United Nation's World Environment Day this year was centered around the theme of "Green Economy: Does It Include You?" Our plant in Halol took the theme to heart by ensuring that its observances were as inclusive as possible. School and college students were invited to enter poster drawing and speech elocution competitions. Another competition invited employees to submit water conservation and waste reduction ideas. Partnering with a local university, they also held a seminar on the green economy and capped the day off with the planting of 50 trees.
Our powertrain facility participated in an eco-forum on green economy as part of the regional observance of the United Nations' 2012 Environmental International Day. GM representatives shared a presentation on Modern Technologies for Sustainable Development, which focused on technology for wastewater treatment and air emission reduction. During the forum, GM Powertrain Uzbekistan received a certificate for its environmental achievements. In its quest to be landfill-free, the facility shares canteen waste and grass clippings from lawn mowing with local farmers to feed their livestock. In addition, straw is baled for farmers on vacant areas of the site.
GM Mexico has joined the Alianza Verde Automotriz (AVA), a new initiative organized in collaboration with the Commission for Environmental Cooperation to provide automobile manufacturers and their suppliers the opportunity to address new, innovative and voluntary sustainability projects that will improve their environmental performance and provide value through the automotive supply chain. The initiative is modeled after the Suppliers Partnership for Environment in the U.S. At its second gathering, our representative led AVA's Energy Efficiency Work Group discussion and shared strategies, tools and technology that GM Mexico is using to save energy.