I have a 1 kW system. I've kept an energy audit for the past month (inspired by The Greening of Gavin).

There have been many many cloudy days this month - so the system generated only 15 kW for January.

My question is - if I add another 6 panels (1kW) is it simple maths and that will double my energy generation? Or is it more complicated than that?

I used 10.4 kWh/day on average through January. Sadly there isn't enough room on my roof to fit enough panels to generate enough electricity to cover that. So it's back to the drawing board to work out how to get it down even further. I'm currently looking into those infrared remotely operated power points that allow you to easily turn off appliances that are on standby.