Collector performance is influenced by a wide range of parameters. In order for a system’s effective yield to be predicted these parameters must be known with accuracy. As a general rule the required accuracy can only be achieved by using outdoor measurements.

This is why SPF relies on several fully-equipped solar trackers. A solar simulator is also available for given measurements – in particular in the prototyping stage. A brief summary of the parameters developed for each collector (Solar Collector Factsheets) is available on our homepage. These performance indicators are also released in various formats on our SPF Info-CD, together with an exhaustive parameter statement and a collector yield calculator. 

• Efficiency curve: efficiency in relation to collector temperature and solar radiation
• Angle factor: efficiency in relation to radiation angle
• Time constant/thermal capacity: how quickly a collector responds to changes
• Pressure loss: pressure drop through the collector dependent on flow-rate.