The naming is all a bit missleading, as KERS is energy that would otherwise be lost through the brakes, so is thermal too.
Basically it sounds like 1/3 of the cars power will come from electricity harvested through a number of ways, and its delivery will be intelligently controlled by computers looking at the current position of the car on track and the application of throttle by the driver. Sounds very impressive, but also applicable to road car tech, which at the end of the day, is what the FIA have to get across.
Hopefully it can create similar situations as the KERS GT3 Porsches or the Le Mans Hybrids and create an increased range vs. increased power balancing act that will mix up strategies. Although with no refuelling, its a bit limited.
I also imagine that a car that goes between ~500bhp and ~700bhp depending on the throttle position and track location will be a bit strange for the drivers to get used to. KERS (or ERS) energy to be used to provide low rev anti lag for the Turbo's is almost guaranteed though, and is definitely something that would work in a road car really well.