A large nuclear power plant operates 24/7 along with more traditional fossil-fired facilities. As wind power comes online, there’s excess generation, so some of the baseload generation isn’t needed. However, baseload power generation facilities like that nuclear power plant cannot turn off and on with the wind. Many units take at least six to 24 hours to power down or up. The result is negative pricing—often in penalties of up to $40 per megawatt per instance—generators are forced to absorb.