This episode is also available as a blog post: https://ourfiniteworld.com/2022/09/20/ramping-up-renewables-cant-provide-enough-heat-energy-in-winter/

One of our big needs for energy is heat energy to keep us warm in winter. Solar energy is primarily available in summer. Hydroelectric generation and wind energy are are unpredictable. They both tend to produce peak output in spring, when little heat energy is needed. Even if we ramp them up, they cannot solve our need for winter heat energy.