Ultimately, it doesn’t matter how cheap solar gets unless we can store that energy, and storage on this scale has never been achieved before. Grid-level storage requires colossal batteries. Today’s lithium-ion batteries are woefully inadequate. Their storage capacity would need to be improved ten- to twentyfold, and—if we really want them to be scalable—they have to be built from Earth-abundant elements. Otherwise we’re just exchanging an economy built on the importation of petroleum for one built on the importation of lithium.
