Anyone with an engineering degree knows energy density, given a specific volume or weight, is one of the most important factors when designing vehicles. The lithium-ion battery packs that power modern electric cars are far less energy dense than the gasoline that power internal-combustion cars. They cannot hold nearly as much energy in a given volume or weight, a liability that clearly shows in the relatively short ranges of many electric cars despite heavy battery packs. This is also evident in windmills, an SMR with much smaller footprint = 300 windmills while providing controllable power.