How does the Yield Check help with the annual check-up of my solar system? When you would like to know in what shape your PV system is in, the Yield Check gives the fast and easy answer. Every month your system's energy production is assessed by comparing nominal and actual output. In case some unusual behavior is detected, you're being notified. At the end of the year you obtain a final report with a summary of year-long operation. What makes this service unique is that no on-site measurement equipment is needed. The Yield Check is simply carried out online - no tools and no special expertise required. This is made possible by the Yield Check's link with the national weather satellite. You can rely on the satellite as if it were your personal solar sensor.

What can I learn from the PV system survey? The survey assesses the so-called performance ratio of real-world PV systems. It's a measure of overall system quality. Every system owner should know about it since the performance ratio gives you a much needed reality check. The performance ratio, abbreviated as PR, specifies the difference between what you paid for and what you actually get. PV systems are sold in terms of kilowatt peak system size, but their output is always reduced by an additional factor - and this factor is just the performance ratio. Often generic values are used for the performance ratio neglecting the fact that performance varies widely from system to system. An actual system can have a PR as low as 50% or as high as 90%. By taking a look at our PV system survey, you get a better idea how your own solar system compares with others in the directory.