Hamilton and McLaren used Kers to good effect at times in 2009
Formula 1 teams are discussing the return of Kers power-boost systems.
Ferrari and Renault are leading a push to bring back energy-storage systems similar to those used in 2009 to give seven seconds of extra power per lap.
But there is disagreement on a number of issues, including timing and whether there should be a single supplier.
McLaren's Martin Whitmarsh, chairman of teams' association Fota, said any decision had to based on whether all teams could afford the technology.
Whitmarsh said: "I wouldn't say it's a divisive issue. A lot of the teams cannot afford Kers next year - probably the majority can't. We've got to find something that's affordable and worthwhile for the sport."
Fota is expected to discuss the issue again at a meeting at the Spanish Grand Prix over the weekend of 7-9 May.
If we had a push-to-pass button that you could only use a certain amount of times then we would have something quite exciting
Mercedes team principal
Kers systems are similar to those that are becoming increasingly widespread in road cars, with Toyota, Honda and BMW among those already marketing so-called "hybrid" cars.
They work by storing energy that would otherwise be wasted as heat during braking and re-applying it to either boost power or cut fuel consumption during acceleration.
Kers was the subject of controversy last year and was eventually abandoned on cost grounds for 2010.
The systems were criticised for being too expensive - it is estimated that the teams using them last year, McLaren-Mercedes, Ferrari, Renault and BMW, spent a total of £40m on Kers.
And it is widely believed that the 2009-spec Kers did not provide a big enough boost of power - they were limited by the rules to dispensing 400 kilojoules of energy a lap.
But some leading figures believe Kers should have a place in F1 because the sport should be seen to be pursuing technologies that are crucial to the future of road cars, where reducing energy consumption is becoming a defining objective as supplies of fossil fuels diminish.
They can also be used to improve the racing.
It helps pass on the message that F1 is technological and environmentally friendly, which is a good message
Renault team principal
Whitmarsh said: "McLaren support the idea of Kers in F1 and we'd love to have it.
"What we have to do is look at the bigger picture as F1 has to be sustainable for a minimum of 10 teams and if we are to reintroduce Kers we have to decide the speed which we reintroduce it and make sure it's affordable.
"Last year was interesting because some teams had Kers and others didn't - maybe in the future Kers should be one of those sporting opportunities i.e. have a number of Kers deployments (per lap) that help overtaking.
Mercedes team principal Ross Brawn said the decision was complicated by the planned introduction of new types of engines in 2013 to replace the current normally aspirated 2.4-litre V8s.
"We acknowledge that Kers will have a part to play in future technologies," Brawn said.
"We think the (power) gains available last year were not significant enough and that we should look at Kers in the future with that in mind.
"We would prefer to look at something that is planned and integrated with the new power-train in 2013.
"That doesn't mean to say that Kers can only come in 2013 - maybe it can be anticipated (brought forward) - but if we do a system now and another in 2013 it's a shame.
"The systems we have now, the advantage they offer is probably not enough and we need to look at systems that are substantial enough to help the sporting side of racing.
"If we had a push-to-pass button that you could only use a certain amount of times then we would have something quite exciting.
"So I think Kers has a future but we have to be careful not to rush back to what we had last year which we all agreed was not perhaps a huge success."
Renault team principal Eric Boullier said his team were pushing for a return of Kers.
He told Autosport: "Renault is aiming to have Kers back in 2011 because for us there are many interests in having this.
"First of all we already have the system. We have spent the money to develop Kers [for 2009], so to not use it any more is a bit of a waste of money.
"The second thing is that we believe for the Renault car manufacturer there is a strong interest in using this technology regarding the development of hybrid technology in road cars.
"It also helps pass on the message that F1 is technological and environmentally friendly, which is a good message.
"We are asking for the system to recover more energy - more than the 400KJ than the previous generation - because it can become part of the show as well. It will clearly be an advantage to have Kers as well, and it can help overtaking."
McLaren-Mercedes, Ferrari, Renault and BMW started last year using Kers systems, but all found difficulty in packaging into their cars while retaining competitiveness.
Only McLaren and Ferrari used it throughout the year, with BMW and Renault both abandoning it because they felt their car was quicker without it.
As the year progressed, McLaren were able to develop their car to the point that Kers became a valuable racing tool which helped Lewis Hamilton to win the Hungarian and Singapore Grands Prix.
The system was also instrumental in Ferrari driver Kimi Raikkonen's victory in the Belgian Grand Prix.
Brundle and McLaren explain Kers