One common misperception about nuclear energy is that it is inflexible, and thus inherently incompatible in a system comprised of variable renewables. But in reality, nuclear is already operating flexibly, and the next generation of advanced reactors will only expand this capability. There are 58 reactors in France that have been operating flexibly for more than 30 years, and that can vary their output between 20% and 100% in as little as 30 minutes. This level of flexibility balances generation and demand, allowing renewables to contribute to the grid intermittently without any additional support from emissions-producing sources like coal or natural gas.

There are also companies working to make the existing fleet and, more importantly, the next generation of reactors more flexible by allowing for even more rapid and efficient ramping. For example, the NuScale small modular reactor (SMR) design has 12 separate modules that can be individually dialed back throughout the day — or even taken offline for an afternoon — to maximize use of renewables during their peak hours and ensure energy demand is met. That means nuclear offers a great support system, giving renewables the space to shine when the sun is out and the wind is blowing, but it’s always there when it’s needed.