In his article, What I learned at work this year, Gates wrote: "Global emissions of greenhouse gases went up in 2018. For me, that...reinforces the fact that the only way to prevent the worst climate change scenarios is to get some breakthroughs in clean energy."
Gates welcomed the fact that renewables are getting cheaper and said they should be deployed "wherever it makes sense." But he stressed that they are intermittent sources and that we are "unlikely to have super-cheap batteries anytime soon" that would allow sufficient energy storage for when the sun isn't shining, or the wind isn't blowing.
"Nuclear is ideal for dealing with climate change because it is the only carbon-free, scalable energy source that’s available 24 hours a day," Gates wrote.
He added that the problems with today’s reactors, such as the risk of accidents, can be solved through innovation.
Gates said that the USA is uniquely suited to create these advances with its world-class scientists, entrepreneurs, and investment capital. But, "Unfortunately, America is no longer the global leader on nuclear energy that it was 50 years ago. To regain this position, it will need to commit new funding, update regulations, and show investors that it’s serious."
Several promising ideas in advanced nuclear technologies should be explored if these obstacles can be overcome, Gates said.
One is the travelling wave reactor, owned by TerraPower; a company Gates started ten years ago. The TWR is a liquid sodium-cooled fast reactor that uses depleted or natural uranium as fuel. The reactor design was first developed in the 1950s, but was revived in the early 1990s. It was later patented by Intellectual Ventures, the company from which TerraPower emerged
Gates said TerraPower had hoped to build a pilot project in China, but that "recent policy changes in the US have made that unlikely."
"We may be able to build it in the United States if the funding and regulatory changes that I mentioned earlier happen. The world needs to be working on lots of solutions to stop climate change. Advanced nuclear is one, and I hope to persuade US leaders to get into the game."