The US National Renewable Energy Laboratory examined five-year data to observe the most common system failure points and how to prevent them. Researchers considered residential, commercial and utility scale plants and found interesting results. While failures cannot be avoided completely, a key takeaway was that close monitoring and timely repair can effectively mitigate the financial effects of failures.
NREL has published a paper showing an experimental solar cell, with a unique technique for wiring two separate solar cells into one, that increased the cell’s efficiency by 4%. The document also offers a respectable review of other technologies being developed.