Again, this is averaged out over the year where the home will be drawing or producing a net amount of energy over the year, and that's the whole thing. There are times the house will have to draw more energy than it would produce, and that's the beauty of net-zero energy. You can pull from the grid when you need to or you can send back to the grid when you have to or can. That's essentially where you have periods in the house when people have the plasma TV on, hair dryers, radios, and everything else, and then you'll see a peak.
On May 7th, 2007. See this statement in context.