Gravity batteries, gigantic bricks, packed full of compressed dirt, as big as a pickup truck, and about five times heavier, are a potentially important solution to a critical problem with the green energy revolution: making sure electricity is available when we need it, not just during the times when sun and wind supply it. Fariba Mamaghani, Assistant Professor at Tulane University A. B. Freeman School of Business, joins Newell to explain how the technology works.