Kimi Raikkonen has obstacles to overcome on his return to Formula One

t is marvellous news for the sport but the Finn's appetite will be severely tested at Lotus

Kimi Raikkonen has announced his return to Formula One next season by signing a two-year deal with Lotus Renault. Photograph: Jef Briguet/EPA

Kimi Raikkonen insists he is fully motivated for his return to Formula Onenext season, which was announced on Tuesday.

Raikkonen, the 2007 world champion, has signed a two‑year deal with Lotus Renault – who will be called Lotus next season – following two years away from the sport.

"I wouldn't come back if I wouldn't be motivated," he said. "There's always a lot of talk about motivation to race, but nobody really knows what I do or what I think apart from myself, so I don't really care what people think. I wouldn't put my name on the contract if I didn't think that I would really enjoy it. It will be exciting to get back."

The signing is wonderful news for Formula One. It means that a quarter of the 24-strong field will be made up by world champions next season. It will also shake up a grid that has had a samey look lately, although Felipe Massa (Ferrari), Mark Webber (Red Bull) and Michael Schumacher (Mercedes) are all expected to make way at the end of next season.

The move, however, represents an enormous gamble for Renault and Raikkonen himself. Although Lotus Renault finished the top team among the five midfielders, they have had a very difficult season.

It started badly when they lost their inspirational team leader, Robert Kubica, who was seriously injured in a rallying accident in February. Kubica, with his speed and error-free driving, gave the bigger teams a run for their considerable money last season. More than that, he was popular and immensely hard-working.

It went wrong for Renault again when the revolutionary forward-facing exhaust system did not work as well as they had hoped. By then, of course, it was too late to change.

Now, the fact that they are changing their name suggests this is an outfit with an identity problem. And if their self-esteem is fragile the high-maintenance Raikkonen may not be the man to restore it.

The Iceman will be ferociously fast, of course. He always had raw speed and at 32 is unlikely to have lost that. But he will find the field faster and even more competitive than when he left.

Two years is an aeon to be out of F1, which Kubica will learn if he ever makes a comeback. There are a lot of new things to think about for Raikkonen, including DRS, Kers and Pirelli tyres.

No one doubts the Finn's ability. He had 16 poles, 18 wins and 62 podium finishes in the first part of his career. But talent alone is never enough and by the end of his spell at Ferrari, by which time he was being outperformed by Massa, he was looking increasingly distracted and there were rumours, when he was linked with Williams recently, that he did not relish all the travelling – F1 folk make Marco Polo look like a couch potato.

If he got fed up with driving a Ferrari, the biggest and most glamorous of all the teams, as he appeared to do, what will happen at Renault, a midfield outfit who are unlikely to be challenging the top teams next year?

"My time in the World Rally Championship has been a useful stage in my career as a driver, but I can't deny the fact that my hunger for F1 has recently become overwhelming," Raikkoen said. "I'm looking forward to playing an important role in pushing the team to the very front of the grid."

It sounds good. But two years of average results in rallying suggest that this is not always the most driven of drivers.