This solar power installation design by RAFAA Architecture and Design with built-in pumped water energy storage is able to regulate its energy capacity by siphoning off excess electricity to pump water into a holding tower. Then, as the sun is set or behind the clouds, the water is released as required to keep the energy flowing into the grid by harnessing the stored energy (mass+force of gravity) with turbines along its fall. It is almost as if Olafur Eliasson had modified his New York City Waterfalls project for a Land Art Generator Initiative design. It is conceived to help power the 2016 Olympic Games in Rio de Janeiro and we really hope that it can get built.
It's not very easy with the resolution of the images that are available online to read the details of how it works. My only question is that it seems that there may not be enough water storage capacity at the top of the waterfall structure to sustain a prolonged deluge as might be required to keep the energy going over long periods without sunlight. It may have been better to use one of Rio's many existing bare-rock cliff faces, which could house a large reservoir at its peak that could potentially be emptied for cloudy days on end. But it's still a great concept as is. The iconic form of it rising above the earth wouldn't be there in my suggested alteration.