4% higher energy conversion from BP 7180 modules

BP Solar had previously studied anti-reflective (AR) coated glass from several different manufacturers under extensive accelerated environmental testing and found a 2.4 to 3.0% increase in output power at STC (Standard Test conditions) for both BP Saturn 7-Series (Saturn mono-) and BP Poly 3-Series (multi-) crystalline silicon PV modules.

The AR coating changes the front surface reflection in a manner which is both Angle of Incidence (AOI) and wavelength dependent and thus the outdoor gain will depend on the prevailing meteorological conditions.

Pairs of modules were monitored at ISET, Germany and Homebush, Australia to prove >4% energy gain over a year. Subsequently two 41.5 kWp nominal arrays identical except for the type of glass used were installed in April 2005 in Germany and monitored for 13 months.

At high irradiances near noon the AC power gain of the installed system is around 3%, rising to 5% under diffuse light and >8% on a bright early morning / late afternoon.In total the array with AR coated glass has produced an average of 4% more energy than the array with standard glass over the 13 months of monitoring.

By A. Artigao, D.W. Cunningham, K.Deponte, J.M. Fernandez, A.M. Nguyen, S. J. Ransome, J. Shaner and J.H. Wohlgemuth, BP Solar.