Original Palo Alto site with data is available here
Below you can see the same data, but I hijacked the frame and edited it a bit.
Palo Alto Demonstration Sites
Five sites, located in the City of Palo Alto, demonstrate a variety of photovoltaic products and applications, both in a residential and commercial setting. At each site, performance data is recorded, stored, and then posted to the internet for viewing. By monitoring these 5 sites we aim to learn more about the performance characteristics of photovoltaic systems and apply lessons learned to optimizing future installations.
The PV performance data from each site is available for viewing in tabular or graphic format. Monthly data may also be downloaded in ASCII format.