In a word, reliability. Nuclear is /by far/ the most reliable energy source.
Nuclear power plants produce maximum power 92.5% of the time. Compare that to other energy sources:
- Geothermal: 74.3%
- Nat gas: 56.6%
- Hydropower: 41.5%
- Coal: 40.2%
- Wind: 35.4%
- Solar: 24.9%
Batteries are a joke. Consider the 409MW / 900MWh battery at Florida Power & Light: this is only enough to power 329,000 homes just over two hours. What happens after the juice runs out? In a day the RE Ginna Nuclear Plant in New York operates at 582 MW--in 24 hours thats 13,968MWh guaranteed! [3] That's powering over 329,000 or more homes without fear of outages. Battery systems in conjunction with renewables brings the capital cost per kwh of nuclear vs renewable to closer to 2:1 (6k $/kW vs 3k $/kW) too. So you're essentially getting 3x the reliability for 2x the cost when using nuclear and outages that exceed a few hours are a non issue. [4]
Coal and gas sure, but renewables are obviously dependent on weather. Nobody runs their solar panels less than maximally possible "because they can". When there is significant oversupply of energy from solar, it gets sold for pennies on the dollar to neighbouring regions, and when the sun doesn't shine, you're sol.
That's not what this is about. Negative electricity prices are rare, and do not account for the massive difference in utilization between renewables and nuclear. By the way nuclear power output can be ramped up and down by a lot, and in a matter of minutes in case of unplanned problems, even if it can't (really shouldn't) go to dead zero.
The person I responded to claimed that nuclear plants run at close to 100% because they bid low because the marginal cost of their electricity production is low, but the same is true for renewables like wind and solar. Yet these renewables run at much lower utilization rates - because of weather and daylight cycle, not "because they can", except in rare cases of negative prices as you mentioned.
Nuclear power plants produce maximum power 92.5% of the time. Compare that to other energy sources:
- Geothermal: 74.3%
- Nat gas: 56.6%
- Hydropower: 41.5%
- Coal: 40.2%
- Wind: 35.4%
- Solar: 24.9%
Batteries are a joke. Consider the 409MW / 900MWh battery at Florida Power & Light: this is only enough to power 329,000 homes just over two hours. What happens after the juice runs out? In a day the RE Ginna Nuclear Plant in New York operates at 582 MW--in 24 hours thats 13,968MWh guaranteed! [3] That's powering over 329,000 or more homes without fear of outages. Battery systems in conjunction with renewables brings the capital cost per kwh of nuclear vs renewable to closer to 2:1 (6k $/kW vs 3k $/kW) too. So you're essentially getting 3x the reliability for 2x the cost when using nuclear and outages that exceed a few hours are a non issue. [4]
[1]: https://www.energy.gov/ne/articles/nuclear-power-most-reliab...
[2]: https://www.energy-storage.news/worlds-biggest-solar-charged...
[3]: https://www.eia.gov/tools/faqs/faq.php?id=104&t=3
[4]: https://www.eia.gov/analysis/studies/powerplants/capitalcost... page 28