The PVOutput API allows solar panel owners to plug their data into the PVOutput website so that they and others can track and compare their results. The data also get compiled into regional and international rankings, as the donut graph illustrates below.
The API has a limit of 60 requests per hour for updates (add) and 60/hour for retrieves (get).
As Warwick Johnston noted in the Australian news site REneweconomy, the compiled data from Australia, where PVOutput is based, was clear enough to register the drop in output during the solar eclipse there on November 14. He notes that, "Australian PV system installations reached a cumulative 2GW in October."
PVOutput also looks at energy consumption as well as generation,
"While pvoutput is primarily focused on monitoring energy generation, it also provides equally capabable facilities to upload and monitor energy consumption data from various energy monitoring devices.
Both solar generation and energy consumption data can be combined to provide a 'Net' view of energy being either generated or consumed live."
So far nearly 400 teams from around the world have registered, and site visitors can see the teams, size of the installations, the efficiency as measured in kw/hour, the number of systems the team has, the number of days the installation has been running, and even a measure of the installation's "health." Daily measurements of the weather (cloud cover, temperature), timezone and other data are also incorporated.