what is a “rolling blackout” ?

310 viewsEngineeringOther

Can someone please explain how rolling blackouts work?

In: Engineering

3 Answers

Anonymous 0 Comments

Phased blackouts is probably a better way of describing it. The power company turns sections of the power grid off for certain regions for a short time. Then, before the power cuts cause too many issues, a new section is cut off and power is restored to the first area.

There is some consideration given to essential services like hospitals, municipal water works and so on. Those should never see their power cut. Also, things like gas stations and EV Chargers won’t see their power cut because transportation is also essential.

Basically the grid operators have decided that they’re shedding some load to match demand to supply. The ‘rolling’ part is an indication that it’s planned and not a catastrophic event.

Anonymous 0 Comments

The general idea is that groups of customers will have power disconnected in a alternating pattern to reduce the load on the system

Such an approach (only having a fraction shutt off at a time) is often preferably to keeping some customers off for a long time or risking a total collapse of the network.

Anonymous 0 Comments

In a power grid the amount of electricity produced needs to match the amount of electricity consumed exactly. If not then catastrophic things will happen. If there is a local imbalance then the transfer lines to neighboring areas will fail, either the fuses trip or the lines literally melt. If there is an imbalance in the entire grid, or if the grid is split due to failed lines, then the frequency will not be correct and various appliances in peoples homes will start failing.

It is therefore better to have the power fail completely rather then be imbalanced. As an emergency effort to reduce electricity demand the grid operators can literally disconnect parts of the consumers. Usually a neighborhood at a time. In order to make it a bit fair and to make sure everyone at least get some electricity if it is critical they will alter which neighborhood gets disconnected. So the blackout will literally “roll” through the city from neighborhood to neighborhood.