Electricity is often generated hundreds of kilometres from where it’s consumed. (Think offshore wind farms and remote hydroelectric dams.) The most efficient and economical way to move electricity over those kinds of distances is through high-voltage direct current (HVDC) transmission lines — so-called “power superhighways.” 

However, addressing faults like voltage or current spikes and short circuits is far more difficult in an HVDC grid than in a standard AC grid, because they travel so much…