Communication and baseline setting for local community impact has been a key challenge despite almost two years of engagements, said project developer SaraCarbon, whose carbon project is the state's first in line for Verra certification.

Studio EB Indonesia will still be using coal by 2060, alongside emerging energy sources such as hydrogen and ammonia, policymakers said at an event in Jakarta. Indonesia has the potential to be a regional renewables powerhouse, but barriers such as fossil fuel subsidies are slowing the transition.

Adopting renewables and electricity imports adds to security concerns posed by global gas market volatility. Investors’ cold shoulder towards fossil energy could also threaten the longevity of Singapore’s gas plants, analysts say.

Students from Singapore's Nanyang Technological University says there is a conflict of interest in the oil major's involvement in a project that claims "to help build a more sustainable future," and point to the firm's checkered history on climate. NTU and Exxon have defended the lab, saying it supports the green energy transition.