The London 2012 Olympic games were probably the most eco-friendly games yet. But Brazil, whose hosting 2016, could have the world's first net-zero energy stadium.

What's net-zero? According to the U.S. Department of Energy, it's one that consumes no energy and emits no carbon on an annual basis. Upgrades to the existing Estádio Nacional de Brasília will help it achieve that goal, but the modifications are in places few visitors will see: the roof.

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A ring of rooftop photovoltaic panels will collect energy to power the stadium. A photocatalytic membrane will collect air pollution and break down the chemicals to remove toxins from the air. These and other upgrades like rainwater collection for landscaping and plumbing will earn the stadium a LEED Platinum status.

The construction will cost over $400 million, but the returns from investing in this kind of renewable energy should even out in about 10 to 12 years. The stadium should be finished by the end of the year, two years ahead of its first major event, the 2014 World Cup.

via CoExist

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