Go 100% renewable! That’s the goal for many, and the world is rapidly switching from fossil fuels to solar and wind energy (though possibly not quickly enough for the planet.) A recent study of 36 years of weather data suggests that 80% is feasible, but reaching 100% requires storage, more transmission lines, or both. The cost of providing that last 20% with storage is about $2.5T. The debate over the details and specifics will continue, and continue to change as increased volume production lowers prices, technology advances, climate changes, and fossil fuel prices respond to significantly reduced demand. In the meantime, solar produces about 1% of US energy and wind produces about 6% of US energy. Depending on the definition of renewable, nuclear produces 20% and hydroelectric produces about 7%. The goal of 100% may not be reasonable, but currently, wind + solar + hydro ~ 14%; which means there’s a long time and a lot of positive improvements to witness and experience over the next several years.