By the 1920s, most urban areas in the US had electricity, but rural areas did not have electricity until the 1930s. New power plants and power lines were expensive. So the states allowed electricity providers to form monopolies. For this, everyone got an electricity connection. During the First World War, electricity capacities were exhausted in some places. In order to pool resources, more and more regions are merging their networks. Until North America only had five power grids: East, West, Quebec, Alaska and Texas.
In the 1970s, Congress opened up the power lines to companies that could generate cheaper electricity. As a result, many suppliers got their electricity from more distant sources. The supply chain was never designed for such loads. And the common lines were never patched. That became noticeable in the early 2000s. In 2003, tree branches downed some power lines in Ohio. 50 million people were without electricity.
Stand-alone grids are designed to prevent major power outages
Real-time monitoring of the network could help: it recognizes the warning signs of an imminent power failure. Then the failures can be limited to a small area or prevented entirely. In 2007, Congress called for the development of a “smart grid.” Since then, the government has invested billions of dollars in this goal.
Many intelligent power grids are to consist of microgrids, in English »island grids«. These are local power grids that supply small areas and are connected to a larger grid at the same time. The advantage: If a line fails, the associated stand-alone grid can be disconnected. As a result, the power outage does not spread further. Smart grids could also include novel long-distance connections using direct current. In direct current lines like this, energy can be transported over longer distances more efficiently than before. And renewable energy sources often produce direct current anyway. If more electricity comes from solar or wind power plants, you need huge battery storage that can be switched on and off quickly. They should cover the electricity demand on days with little sun or wind.