We have a 4kW array made up or 20 of these 200W panels. The system powered on in November 2007 and has been working great, even here in the rainy NW corner of Oregon. You can see the system's performance in near real-time here: http://tinyurl.com/2vxq37

Now, in early April, it is generating power from 8AM till 8PM.

By using these higher efficiency panels, we were able to buy fewer panels, pay less for the install and railings and we still have room on our roof where we hope to add more solar panels soon.