The PV industry has grown up: it now requires solid ground for decision-making. We need to deliver the most accurate yield estimates and performance evaluations possible. Good irradiation data is crucial, says Karel De Brabandere, senior PV expert at 3Es research lab and main author of new analysis of irradiation data sources.
Until now, there were typically 3 commonly used sources of irradiation data for a site: standard sensor measurements, pyranometer measurements or satellite data. One source is chosen for yield or performance calculations depending on costs or levels of accuracy / availability required.
The new study by 3Es in-house research team shows that sensor data, although still widely used, is generally not accurate enough to be bankable or reliable enough as a basis for key O&M decisions. Satellite data performs better but is not as accurate as pyranometer measurement data. On the other hand, pyranometers require careful installation and maintenance, which can be costly.
Pyranometers clearly deliver the best data says Elvin Lemmens, PV engineer in 3Es consultancy team But, when inspecting sites, I regularly come across pyranometers that have been neglected, or worse yet, are not installed properly at all. This makes the data less reliable, and sometimes unusable if bankability is at stake. It is very unfortunate.
The Smart Irradiation Service was developed in response to these findings. Even without hardware on site, it delivers data that is 40% more accurate than satellite data on a monthly level, and even more on a yearly level, where it is on par with pyranometer data. The service combines available satellite data with data pooled from a network of quality-controlled ground measurements and delivers yield calculations on a daily basis.
Integrated as an option in SynaptiQ, 3Es PV monitoring and reporting software, it delivers more reliable Performance Ratio (PR) calculations and can therefore be used to target O&M processes or deliver more accurate reporting to investors. 3E is now launching its Smart Irradiation Service and is publishing the results of its analysis of irradiation sources -including the new service- as a white paper, available on www.3E.eu.
To find out more about the accuracy of solar yield calculations, download 3Es white paper: http://www.3e.eu/projects/publications-and-downloads/ For more details on the Smart Irradiation Service, download the service leaflet: www.3E.eu For more information about 3Es services and analyses, please contact claire.grandadam(at)3E(dot)eu
