Another completely misleading article on gravity batteries. All the solid weight stuff is bunk, probably designed to suck out money from naive investors / corrupt state officials. Moving solid weights gives only a very small electric power, so building the proposed solid weight batteries gives units of MW at most, which is uneconomical. Unless it transports a large lake of water up and down a hill like in pumped-storage hydroelectric plants, and can provide tens or hundreds of MW. Such installations are very expensive to build today, because all the low-hanging fruit options seem to have been already built.