We had solar panels installed by nu energy in 2010..it never crossed our minds that there were different qualities of solar panels. Had no problems til jan this year when I noticed one panel was cracked. Rang up nu energy who said take a piccie and we will replace it. So took the piccie and waited...and waited...and waited!!! Apparently our system is now obselite and the spares were only to be found in china. They were struggling to source them. After 4 months of us being promised it was on its way we spoke to the lady in charge of the whole nu energy replacement fiasco..she was at her wits end!!! She promised she would have one couried to us in a few days!! Yeah right we though..but...it arrived. It then took another 3 months for the guy to come and install. We were promised all along it the broken panel was completely safe...when the guy removed it he said it was a miracle it hadn't caught fire. We have a 20 year warranty on it...I don't hold out much hope!!!