How can you get to 100% renewables using solar and wind? We don't have the capability to store enough energy to get through a few days without wind, especially

How can you get to 100% renewables using solar and wind? We don't have the capability to store enough energy to get through a few days without wind, especially during the winter months in northern countries where solar doesn't produce much energy. Nuclear energy may take longer and may be more expensive (not sure that's still the case when you build a few hundred plants), but it least it provides reliable energy all year.