Craig Scarborough has reported new information on this Renault problem on the Pit Stop Radio Show podcast on Monday evening. One can download the show here, also.
@ minute 14:17, after discussing the ES problem briefly, Craig then says the big problem is in the ERS-K system. He said
the ERS-K was apparently bringing its power in too quickly back to the ICE mainshaft, causing failure in the ERS-K, and the crankcase itself. He said there is a fundamental problem with the shaft of the ERS-K. Consequently, they now have a big redesign.
"For the rest of testing, they're going to have to without full ERS power... There is also some debate as to whether this part will be ready for Melbourne as well.
So potentially for some of the first races the Renault engines could be handicapped because of this problem with this motor generator."
http://forums.autosport.com/topic/191766-renault-problems-are-catastrophic/?p=6585453