Solar City Tower
Designed specially for the 2016 Olympics in Rio de Janeiro, this stunning energy-generating waterfall display will be located on Cotunduba Island and will serve as a beacon to all those arriving in Rio by sea or air. The Solar City Tower will be the iconic symbol of Rio's efforts to make the 2016 Summer Games the first zero-carbon footprint games in history.
Designed by RAFAA Architecture and Design, the tower's interplay of renewable energies is impressive. It all begins with the power generated by solar panels, which will produce energy for the Olympic village by day, then pump seawater by night. That seawater will then be released to drive turbines. It can also be pumped over the top of the building to create a breathtaking wall of water.
There will supposedly also be a retractable platform equipped for bungee jumping from the top, which isn't so much sustainable as it is cool.