The electricity that people use is generally produced and supplied by companies. Load shedding results when people are demanding more electricity than a company has to give. To resolve the situation, that company may have to deny certain users electricity at certain times. This prevents blackouts from occurring which causes instability in a country and is not good for the economy.
Many people take electricity for granted. This is often because people think electricity is unlimited. In many parts of the world, especially in developing countries, this is not true.
Providing electricity involves converting some type of resource into energy that can be used to produce the needed electricity. For example, coal or hydropower may be used. Companies involved in this process usually have a limited capacity, meaning they can only produce so much. There are also instances when the resources used to produce the electrical power are limited or unavailable.
Load shedding occurs when consumers demand levels of supply that exceed their providers’ capacities. When these types of threats are looming, people are often warned to conserve electricity and limit their consumption. This strategy often proves ineffective, so the providers must resort to more drastic measures. However, there are solutions available that will do load shedding by interfacing with small demand controllers in thousands of locations. When a demand peak is coming, the utility can quickly respond by invoking the demand controllers to shed unnecessary loads. For example, it can turn of an air conditioner, or a pump or a portion of the lighting load. If the utility does demand control for small equipment over thousands of locations, it can reduce the overall energy usage substantially.
However, sometimes the government does not want to spend money on these type of systems and a blackout occurs. A blackout is usually an uncontrolled power outage. If excessive demands are left unresolved, this will be the result. Blackouts, however, can be problematic. Since consumers have no indication of when a blackout will occur, they can be unduly inconvenienced. For providers, blackouts can result in damaged networks.
Load shedding is a controlled alternative response to excessive demand. To ease the burden on themselves and their consumers, providers may begin to ration electricity. Instead of allowing a blackout to occur, which could cause many people to be without power for an unknown amount of time, providers may shut down the flow themselves.
This is usually part of a plan. The providers decide how to best distribute the electricity so the burden of the shortage can be spread across their networks. Load shedding often involves schedules that determine which areas will be denied power and at what times it will happen.
Load shedding is referred to as rolling blackouts for this reason. First, the flow of electricity is cut in one area for a predetermined amount of time. Then, supplies are reconnected in that area and disconnected elsewhere. In many cases people in the affected areas, especially the businesses such as supermarkets that are dependent on power, are notified in advance.