Balanced Network describes how the Indigo Tower works here.
During the day the reaction is naturally powered by sunlight acting on the titanium dioxide skin. At night the reaction is maintained by a series of ultraviolet lights that are powered by energy collected from photovoltaic panels during the day.
The tower will be a glowing indigo object at night varying in intensity according to the amount of solar energy collected during the day. The indigo glow will become symbolic of the 24-hour cleansing; counteracting the haze that often dominates more and more cities around the world.
And the connection to greywater you ask?
A series of gardens are located at regular intervals all the way up the tower. They become public gathering spaces as well as marsh lands to collect the water from the chemical reactions of the skin and to filter and process gray water from the towers. The plants also turn the carbon dioxide, created in the chemical reaction of the skin, back into oxygen.
It is paramount to have the plants help maintain the base-level carbon neutrality. A large pool around the base of the tower is the final collection point of the filtered water, which goes to support a large amount of animal and plant life. Water is also pumped back up the towers from the pool to service toilets. Furthermore, the pool at the base acts as a heat sink for the release of the heat generated from a back-up air-conditioning system. Here, the heat is released slowly, thus helps reduce the heat island effect.
Earth to Oregon Sustainability Center - now here is a building design that is truly going to set Oregon apart from those other *Living Buildings* and might turn the heads of those skeptical politicians.