Wind, solar, geothermal, hydro, wave energy ... Renewable sources are a crucial pillar of any plan to decarbonize the world's energy generation industries and eliminate fossil fuel use. But for many reasons – intermittency, location dependency, land requirements, and others – they can't do it alone.

To fully remove greenhouse gases from the world's energy sectors, there needs to be a cheap, scalable form of zero-emissions energy that can reliably produce power 24/7/365. All the better if it can rapidly ramp its output up and down to help the power grid cope with load spikes and interruptions in renewable energy supplies. The best candidate to fill this role right now is advanced nuclear power.

While nobody wants their back yard to become synonymous with Chernobyl or Fukushima, nuclear is demonstrably one of the safest forms of energy generation. Where coal and oil-derived energy cause 24.6 and 18.4 fatalities per terawatt of energy supplied, nuclear power has caused just 0.07 – and that includes the high-profile disasters that have led to its sullied reputation.

Considering the projected death toll of a 2°C temperature rise – somewhere between 300 million and 3 billion premature deaths spread over one to two centuries – the fourth generation of nuclear power is well and truly back on the table, and with many decades of development, advanced modeling and materials technology on its side, it's likely set to improve its already excellent safety record.

One promising initiative that has been backed by heavy private investment as well as the US Department of Energy is a collaboration between Bill Gates's Terrapower and GE Hitachi Nuclear Energy. Natrium (latin for sodium) is getting the chance to demonstrate its "cost-competitive, sodium fast reactor with a molten salt energy storage system" at proper commercial scale thanks in part to a US$80 million DoE grant announced in October.