Google's approach with this and other projects is to solve the "people problem" first -- in this case, giving people Internet access throughout the city -- and worry about money later
Perhaps google could require a portion of any CPU's resources to be committed to distributed computing projects in return for free Wifi service.
It could enormously increase progress for all sorts of biotech and physics distributed computing projects, as the resources are loaned to them for a fee. As is done now with supercomputers.