Renault has apologised to Red Bull Racing and Lotus following the alternator failures that sidelined both Sebastian Vettel and Romain Grosjean during the European Grand Prix.

Vettel looked set to take a dominant victory until he was forced out on lap 34, while Grosjean retired seven laps later, when he was also running well and in second place. Renault has now promised to 'thoroughly' investigate the matter, although it said currently that problems look to have occurred for 'different reasons'.

"We need to hold our hands up and apologise to both Red Bull and Lotus on the problems on the cars of Sebastian and Romain. Both suffered alternator failures, although it seems for different reasons at this point in time," confirmed Remi Taffin, head of Renault Sport F1's track operations, following the eighth round in the 2012 F1 World Championship in Valencia.

"Sebastian's [alternator] overheated and the engine shut down, while Romain's alternator failed and the electrical power to the engine stopped.

"We will of course thoroughly investigate the reasons for this when we get the units back to Viry to try and ensure that Red Bull and Lotus, plus our other partners, do not have the same issue in the future.

"There is a lot of work to be done between now and Silverstone but we have a strong team and resources in the factory."

Renault's Cyril Dumont added: "Today was a real disappointment as Sebastian was well ahead and seemed to have the race in his pocket.

"Then the alternator overheated, stopped supplying electrical power and the engine shut down. We're not sure exactly why - it could be a number of things - but it's definitely something we'll look at when we get back to Viry," Dumont summed-up.