Photovoltaic System Survey - A new Service for the Solar Community!
The PV system survey is currently under development. Starting in spring 2011, the survey will become available here.
What is the PV System Survey?
The PV system survey is a community activity, open to everyone to participate. The service is made possible by people with solar systems like you. Solar system owners get together, check their system's performance and compare the results with others in the community. The survey builds on a unique cooperation between the community of system owners and focus solar. Community members provide the kilowatt-hour numbers of their systems, and focus solar adds solar radiation information from the weather satellite. The weather satellite takes on the role of being the neutral observer looking down on countless solar installations. Effects of location, size, orientation, and local weather influence are accounted for and what remains is a measurement of performance. At its heart, this activity is about product quality. Otherwise we would only talk about the weather. But what good does it do when solar sales people tell us that sunshine is free? That's a no-brainer. Consumers need to have access to relevant consumer information. And we are in the fortunate position, that we as a community, can conduct the most comprehensive survey possible.
What is the need for a PV System Survey? Isn't it enough that modules are certified?
Yes, PV modules are certified, but there's no certificate for the system as a whole. The community survey is aimed at exactly this goal of identifying losses that are system-specific and which are not yet accounted for when looking at modules isolated from the rest of the system. PV modules are certified in the lab under idealized conditions, that have little to do with the real world. Under real operating conditions additional losses occur - typically 10% to 20%. At this level, performance can still be regarded as expected, but some systems have losses as high as 50%. Often their owners are not aware of such deficiencies and losses go unnoticed. Unfortunately, performance still varies widely from system to system. The community survey is here to shed light on the "dark side" of solar energy and create more transparency for consumers in the solar market.
What services will the PV System Survey provide in the future?
Results from the community-based survey will be published in the form of a searchable database. The database lists performance results that have been released by their owners for public usage. The figure of merit applied hereby is the so-called performance ratio, a common measure of performance in the solar industry. You can search this database for ZIP codes, installers, module and inverter brands, and look for the respective performance numbers. Usage will be free of charge and available to everyone. However, when looking at the results, please remember that this is a community effort. The information is as good as the input that was submitted by our users. Even with good data quality screening, erroneous results cannot be excluded with 100% certainty.