The transformation of the power sector will only get the world one third of the way to a goal of achieving net zero emissions by mid-century, a report by the International Energy Agency (IEA) said on Thursday.
Global carbon dioxide (CO2) emissions are expected to fall this year by 8 per cent from 2019 - their lowest level since 2010 - as slower economic growth due to the Covid-19 pandemic slashed energy demand.
However, the trend is not forecast to continue.
The transport, industry and building sectors currently account for more than 55 per cent of CO2 emissions from the energy system and that is expected to grow due to more vehicles being electrified, metals recycling and heat production for industry and homes, the IEA said.
Electricity generation would need to be around 2.5 times higher in 2050 than it is today, requiring a rate of growth equivalent to the entire US power sector every three years.
Annual additions of renewable electricity capacity, meanwhile, would need to average around four times the current record, which was reached in 2019, the report said.
The report analysed more than 800 technology options to examine what would need to happen for the world to reach net-zero emissions by 2050.
The IEA said between a third and a half of cumulative emissions reductions needed come from technologies which are not commercially available today - for example, low-carbon hydrogen, which is produced by electrolysis powered by renewable energy, and technology to capture carbon emissions released to the atmosphere and store them.
A large amount of additional power generation is needed for low-carbon hydrogen, which is increasingly being viewed as a way for industries such as steel to decarbonise.
The global capacity of electrolysers needs to grow to 3,300 gigawatts (GW) from 0.2 GW today. To produce enough hydrogen to reach net zero emissions, the electrolysers would consume twice the amount of electricity which China generates, the IEA said.
