IEA worried about nuclear energy phase out

The International Energy Agency has warned that a steep decline in nuclear energy capacity will threaten climate goals and power supply security unless advanced economies find a way to extend the lifespan of their reactors.

Nuclear is currently the world's second-largest source of low-carbon electricity, behind hydropower, and accounts for 10 per cent of global electricity generation.

But nuclear fleets in the United States and Europe are on average more than 35 years old and many of the world's 452 reactors are set to close as cheap gas and tighter safety requirements make it uneconomical to operate them.

"Without policy changes, advanced economies could lose 25 per cent of their nuclear capacity by 2025 and as much as two-thirds of it by 2040," the IEA writes in its first major report about nuclear energy in two decades.

Over the past 20 years, wind and solar capacity has increased by 580 gigawatt gigawatts in advanced economies.

Despite that, however, IEA estimates that the 36 per cent share of clean energy sources in global power supply in 2018 was the same as two decades ago because of the decline in nuclear.

In order to offset the expected decline of nuclear in the next two decades, renewables investment would have to grow fivefold, but that would not only be hugely expensive, but would also hit public resistance and require major power grid investment.

IEA director Fatih Birol said the agency is not asking countries who have exited nuclear to reconsider, but that countries who did decide to keep nuclear should do more to support the industry.

"Without action to provide more support for nuclear power, global efforts to transition to a cleaner energy system will become drastically harder," Birol said.

IEA Energy Markets chief Keisuke Sadamori said it is more expensive to build new wind and solar than to extend the lifespan of existing reactors, which require investment of $US500 million to $US1 billion per GW of capacity.