Any thoughts on solar panel obsolescence, solar panel upgrades, etc. – i.e. 25-30 year lifetime is great, but do you anticipate material or other advances to provide a justifiable upgrade projection in 7, 10 or 15 years?
The solar industry is still evolving. Solar modules of the format we are currently using (crystalline cells sandwiched between glass sheets and framed by aluminum) are here to stay for at least the next decade if not the next three decades. The performance of the cells has pretty much been maxed out. The real advances now are simply bringing the cost of manufacturing down. So yes, in 7 or 10 years there will be lower cost solar panels, but I strongly doubt they would have sufficiently improved performance to justify a change-out or upgrade.
Our industry does not yet have sufficient standards in place to make solar panels mix and matchable or plug and play commodity items. Each project is still a custom project and the specific panels are matched to the specific inverters. There are about 600 different makes and models of solar panels and they are all different electrically and in their physical dimensions. So swapping one out for a “better” one in the future will likely not be possible.
The most likely upgrade you could expect would be improved inverter controls which would allow your system to keep running during grid troubles. Given the large number of inverters already deployed, I foresee such improvements being made available as retrofits to existing inverters.
Yes, there could be some step changes in performance improvement in the next ten years. But from what I’ve seen repeatedly since 2006 is that the overall economics of the package don’t improve. If the project makes sense to do now, you should just do it. Those customers I know who waited for something better to come along now generally regret that decision. They could have been saving money all along.