No idea about the US. My frame of reference is an integrated European market in general and the Nordic integrated spot market in particular, which uses Swedish hydro and Danish wind on top of nuclear, biogas and wood pellet market.
Seems to work well enough: https://ourworldindata.org/grapher/co-emissions-per-capita?tab=chart&time=1961..latest&country=USA~DNK~SWE~NOR