Dec 6 (Reuters) - TotalEnergies's CEO gave his backing to an international pledge to triple renewable energy generation at the COP28 climate summit, calling it necessary to phase out fossil fuels and decarbonise.

"It's the right way to frame the object, tripling renewables, because if we don't do that, there's no way to phase out fossil energy," Patrick Pouyanne told Reuters in an interview on the sidelines of the summit in Dubai.

"It's a question of mobilising finance, particularly in many developing countries."

Governments at previous climate talks agreed to phase down the use of unabated coal, but the talks, hosted by oil power United Arab Emirates, have so far been split on the future role of fossil fuels.

The debate has focused on whether to prioritise technology to abate, or capture emissions, or on the shift to renewable energy.

Pouyanne said capturing and storing carbon dioxide was still too costly and not the solution to decarbonisation.

"Decarbonisation is all about electricity and electrification," he said.

At least 118 countries have supported the pledge led by the UAE COP28 Presidency to triple renewable energy capacity by 2030.

Issues including grid connection delays, supply chain bottlenecks and manufacturing capacity have raised questions about the feasibility of the target, although some wind and solar developers have added capacity at a fast pace.

For TotalEnergies, oil and gas is the largest source of its profits, but it aims to grow its renewable business to 100 gigawatts of gross installed capacity by 2030, from 22 gigawatts now.

"The supply chain, if there is the demand, will come," said Pouyanne. "It's not so complex to build a manufacturing plant for solar cells."

He favoured wind and solar projects for now as opposed to green hydrogen, which he said was "premature" for TotalEnergies.

He also said the company's research and development unit was looking into commercial uses for carbon rather than storing it. It remains unclear whether the dozens of carbon capture and storage projects globally are profitable.

(Reporting by Sarah McFarlane; editing by Barbara Lewis)