In the recently concluded 2022 United Nations Climate Change Conference, more commonly referred to as COP27, the call was for the stepping up of the schedule to decarbonize or to get out of coal use as fuel.

Experts reported in the Global Energy Monitor, an industry watchdog, said small modular reactors could play a key role in plans to replace the heart of coal-fired power plants with a low- or zero-emission heat source.

Coal-fired plants have a capacity of over two terawatts worldwide, or around 36 percent of all power generated. These power plants, however, also produce almost a third of total global net annual CO2 emissions.

As such, replacing coal is essential if the world seeks to meet its emissions targets soon but it will not be easy.

More than half of the around 6,500 coal-fired power plants worldwide are less than 14 years old, which means they are unlikely to be decommissioned soon considering growing energy demand and supply shortages.

Maintain infra

Older coal plants are also unlikely to be retired early.

A coal-powered plant provides a reliable baseload against wind and solar intermittency and has valuable energy assets which would be expensive to replace, including transmission connections, cooling water access, real estate holdings, and a skilled workforce.

Far from scaling back on coal use, global operating coal capacity grew by 18.2 gigawatts in 2021, or about 0.86 percent, according to the Global Energy Monitor.

A study conducted by TerraPraxis called "Repowering the Global Coal Fleet by 2050" said a viable option is to close down the plants' polluting elements such as the boiler and replace them with an energy source that has as close to zero emissions as possible while maintaining the surrounding infrastructure.

"Small modular reactors or heat sources (fission, fusion, geothermal) are a key component in the whole deployment solution that is being proposed," TerraPraxis chief technology officer Chirayu Batra said.

Batra said the objective is to develop a standardized, scalable system, with a view to configuring the design to be able to meet any kind of site or plant requirements while also accommodating a range of different heat sources.