IEA PVPS Task 2 supports improved operational and economic performance of new PV systems by providing analysis, and resources that help designers, researchers and others to understand factors governing existing systems’ performance. One of the main outputs of the Task is the Performance Database which consolidates monitored data from over 400 systems in 14 countries.

A summary report presenting graphical analyses covering 395 of the systems constructed before early 2002 has just been published. Using the monthly datasets from the database, the report is an analysis of the equivalent of over 1 200 years of consistent, high quality PV operational data.

The full dataset is dominated by grid-connected plants (total of 339 systems, of which 20 are façade integrated), but useful information on 43 standalone, and 13 stand-alone hybrid systems is also provided. Germany, Japan and Switzerland contribute the majority of reported systems, with 108, 82 and 62 respectively, while Austria, Italy and the Netherlands each contribute between 20 and 30 systems.

Normalized graphs of nominal array power, outages, irradiation, final yield, module temperature, performance ratio, module and inverter efficiency are presented, both as a whole for each system type and again by country for the grid-connected systems. One of the interesting observations from the analysis of the grid-connected subset is that there has been a clear improvement in the average performance ratio (PR) over time. PR is an indication of a system’s actual output compared to the output expected based on its rated capacity and available irradiation. It takes into account losses due to temperature, incomplete utilization of available irradiation, and inefficiencies or failures of system components. For the 132 plants constructed prior to 1995, the average PR was 0,657, while the 207 plants installed from 1996 onwards registered an average PR of 0,702. This is largely mirrored across the reporting countries. An updated version of the PV Performance Database, incorporating new systems’ data as well as additional data for many of the existing systems will be released in June 2005. Both the report and database can be accessed via the PVPS website.

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