On Mon, 28 Mar 2011 23:25:41 -0700 (PDT), harry wrote:

My house will be a net exporter of energy.

I very much doubt that with only a 4kW peak PV array. What are you
going to use for space heating in the middle of winter?

The electric base load of this house is about 1kW. To break even one
would need to have a 4kWp PV array producing 50% of it's capacity for
12hrs day. That just ain't going to happen in winter... And that 1kW
base load is just electric, no space heating.

--
Cheers
Dave.