The contrasts between a nuclear reactor such as Wolf Creek and a solar plant or a wind farm are stark. Nuclear power provides the constant baseload power that is essential to a power grid. Nuclear reactors are independent of when the wind blows or when the sun shines—they operate 24/7—so they have a 90% capacity factor on average (5) instead of 25% for solar or 33% for wind. Since the Wolf Creek nuclear reactor is rated at 1,200 MWe, the long-term average output will actually be about 1,100 MWe. The capacity factor would be even higher if it were not necessary to shut down the reactor every 12 to 18 months to change the fuel, a process that takes a month or more. This down time is scheduled ahead of time so a utility can plan around it—quite different from the intermittency of solar or wind. Except for the fuel change, the reactor is usually running at 100% capac­ity. Nuclear power doesn’t really compete with wind and solar, though. Instead, it reduces the need for coal or natural gas to provide baseload power. Of the CO2-free energy sources (renewable and nuclear), only nuclear can scale up suf­ficiently to displace our huge dependence on coal for baseload power.