Wrenches, There has been substantial interest and discussion about MTBF. As promised last week, here is the link. http://www.enphaseenergy.com/support/downloads.cfm It is near the bottom of the page and is titled "Reliability of Enphase Micro-Inverters". Comments and questions are welcome. -- See Ya! Marv Enphase Energy 707 763-4784 x7016