Interesting:
Apple is also looking to decrease its reliance on electricity provided by the city power grid by building its on-site Central Plant.
What are the benefits of having a dedicated power plant I wonder?
In addition to being able to control the fuel source, the main inefficiency in a power plant is wasted heat. If you've got the ability to use the waste heat from a power plant, say to heat water, then you can increase the overall efficiency significantly. "Combined heat and power" or "cogen" installations are not uncommon.
The three reasons that jump out at me would be:
1) Redundancy.
2) Cupertino wants them off their grid.
3) Or they're going to have a unique power footprint that they don't want to share with the world.
They probably want to have backup generators for 100% of their energy needs, anyways. To make such a setup reliable, they need to have personnel on standby operating it, need to do test runs, etc.
Given that and the scale of this thing, they probably think it is cheaper to run those generators permanently. Of course they would still need some extra generators to allow for maintenance and defects, but I guess that's peanuts compared to the startup cost of having the generators for the entire building.
A couple of ideas:
1. They may feel they can generate it more efficiently (aka cheaply) or with fewer disruptions in service
2. Maybe they're looking at alternative energy sources to further control their environmental footprint
The plan is for (1) a big underground parking lot (2) a separate 4-story parking structure. In Jobs' pitch to the city council, the separate aboveground parking structure was a long rectangle on the south side of the property, near the freeway.
