This. Overloading the local systems can overload the bigger grid, like a PJM (Pennsy-Jersey-Maryland). And if the bigger grid crashes, it would take a LOT longer to bring the system back up. So they limit the load on the local grids to protect the bigger one.
This. Overloading the local systems can overload the bigger grid, like a PJM (Pennsy-Jersey-Maryland). And if the bigger grid crashes, it would take a LOT longer to bring the system back up. So they limit the load on the local grids to protect the bigger one.
https://www.cbsnews.com/philadelphia/news/power-grid-operator-pjm-asks-residents-to-conserve-energy/
https://www.epa.gov/green-power-markets/us-electricity-grid-markets