The amount of renewable electricity capacity installed in 2018 remained level with the previous year, while emissions from the power sector grew, IEA data shows.
The IEA said 177GW of new renewable capacity was added in 2018, the same as 2017, with wind providing 28% of the total.
It is the first time since 2001 the net level of annual installations renewable capacity has not increased, triggering IEA executive director, Fatih Birol, to warn, again, the world is on course to miss the Paris climate targets.
Additions need to grow to 300GW annually between 2018 and 2030 to reach the goals of the Paris Climate Accord from 2015, the IEA said.
"Governments need to act quickly to correct this situation and enable a faster flow of new projects," said Birol.
"Thanks to rapidly declining costs, the competitiveness of renewables is no longer heavily tied to financial incentives.
"What they mainly need are stable policies supported by a long-term vision but also a focus on integrating renewables into power systems in a cost-effective and optimal way. Stop-and-go policies are particularly harmful to markets and jobs," he added.
The IEA warned the 180GW of new capacity is only about "60% of the net additions needed each year to meet long-term climate goals".
Emissions from the power sector, meanwhile, grew 1.7% to a record high 33 gigatonnes, the IEA said.
"[The] 2018 data is deeply worrying, but smart and determined policies can get renewable capacity additions back on an upward trend," Birol added.