Nuclear wins | Runner up: Gas

The electrical grid powers our most critical systems: GPS, communication, traffic lights, hospitals, water, and wastewater treatment. These essential services require reliable electricity 24/7/365 no matter the weather conditions.

Reliability is defined by availability on demand: can people get the electricity they need when they need it? 

The reliability of nuclear power is second to none. US nuclear plants operate 24/7/365. The only time they don’t generate power is when they’re shut down for refueling, something large reactors undergo every 18 to 24 months.

Natural gas comes in second for reliability. Natural gas plants have a proven track record, but they usually don’t store gas onsite. They’re supplied with gas through pipelines. If there’s a problem with the pipeline that feeds gas to a power plant, the plant may not be able to operate. Still, natural gas is more reliable than wind and solar power. 

The problem with wind and solar power is that neither is available on demand. Each depends on the weather to cooperate: the wind needs to blow, and the sun needs to shine for them to work. But sometimes neither is the case. For example, in the summer of 2022, power demand surged in Texas, pushing the grid to the brink of blackouts, yet wind generation produced less than 3% of its total capacity in Texas. The wind often doesn’t blow when it’s needed most. Likewise, many places have frequent cloud cover, and sunlight decreases in winter months—conditions that impede solar plants. Dependence on the weather makes wind and solar the least reliable sources of energy. 

Some people imagine that we can make wind and solar more reliable by storing surplus wind and solar energy in batteries. But this is unrealistic. In reality, batteries cost too much to store energy at scale. If, for instance, we used batteries like Tesla’s megapacks, it would cost over $590 trillion—six times the GDP of the entire world—to store only three days of energy. Alex Epstein wrote about this on Twitter on January 25, 2023, after looking up the price of the megapacks: “The world uses over 165k TWh of energy annually, or ~1.36 billion MWh in 3 days. 1000 Tesla Megapacks (3916 MWh of storage) have a price over >$1.7 billion. This would mean 3 days of storage using Tesla batteries would cost >$590 trillion. That's 6X world GDP!”

And even three days of energy wouldn’t come anywhere close to providing the world with reliable energy because many places experience many weeks of uncooperative weather. Germany, for example, would need to build 12 weeks of energy storage (36 TWh) to go 100% renewable.

It’s unrealistic to expect that a country like the US can rely on wind and solar to meet its need for reliable energy—as unrealistic as expecting an inexperienced part-time employee to suddenly begin working 24/7 and managing the whole operation. In fact, adding solar and wind power sources to the US electrical grid poses a threat to its reliability—the Number 1 threat, according to The North American Electric Reliability Corporation (NERC), a trusted nonprofit organization that monitors the reliability, resilience, and security of the grid.

Nuclear and natural gas are clear winners when it comes to energy reliability.