Williams technical director Sam Michael says the team could elect to run a flywheel version of KERS during the 2011 season, although such a move is more likely to take place next year.

The team has elected to run with a battery-based KERS system this year despite developing a flywheel version of the system, with the need to tightly package the rear end of the car making it difficult to utilise the flywheel system.

The current KERS system is housed underneath the chassis of the car but Michael insists that the flywheel could be used for 2012 and possibly earlier, although next year is a more realistic target.

"All of our KERS system is contained under the chassis," he said. "We did that mainly for aerodynamic reasons. Previously people have pushed out into the sidepods. But when you do that you effect the undercut. The undercut is where the sidepods scoop in above the floor. If you package the KERS out there you start to push the undercut wider and lose downforce. Immediately we said we wanted to keep everything inside the chassis and if necessary make the chassis longer, which is what we did, because that is not really a penalty. Everything is contained underneath.

"As you know, Williams Hybrid Power, developed a flywheel. We did consider a flywheel for this car. It was very close. But unfortunately the packaging stopped us from doing that to start with. But we haven't discounted introducing a flywheel to this car at some point. It would be very unlikely during 2011. But definitely it will be on the cards for 2012."