What is load-shedding?

Answer

load shedding, normally used in industrial, large commercial, and utility operations, is monitoring electric usage continuously (usually by automated instrumentation) and shutting down certain pre-arranged electric loads or devices if a certain upper threshold of electric usage is approached. there are two reasons for doing it, both of them financially motivated.

power companies sometimes set up an industrial customer or a school with an electric billing rate in steps, i.e. if you are pulling less than this amount of electric current during certain times you get billed at one rate for the electricity you use but if you are pulling MORE than this amount of electric current during that time, you get billed at a higher rate, even if you use the same amount of electricity overall. the highest current you draw during the time period in question is your "peak demand". the power company has to have generating capacity built and in place to generate the sum of all of the "peak demands" of its customers during the highest peak demand period. say that period is 10 am to 12 am during weekdays. if the highest peak demand exceeds the capacity of the power company to generate, they either have to build another power station to cover that 2 hour period each day, which is a waste of money, or they have to buy power from some other power company during those 2 hours which is also expensive. so power companies look for ways to cut down on the highest peak demand. they encourage their large customers to cut back on peak demand during those "highest peak demand periods" by charging them more if they exceed a certain peak demand. customers can stay below this set peak demand limit by monitoring their electric demand and cutting off unnecessary electric loads if they get too close to their demand limit. that is one form of load shedding.

the other way is for the power companies to ask their small customers for permission to install a piece of equipment in their home or business and wire one or two appliances to the equipment which will shut down the appliances based on a radio signal from the power company. the appliances are usually electric water heaters. the power company gives a discount to these customers. then, if the power company sees that it's demand is coming close to its generating capacity, it sends out a signal and cuts off all these appliances. that is also called load shedding.

First answer by Zeumer. Last edit by Zeumer. Contributor trust: 234 [recommend contributor]. Question popularity: 59 [recommend question]