Power rolling blackouts, or load shedding, are when the demand for electricity or power exceeds the available supply. This causes instability in the grid as all the consumers attempt to pull the insufficient capacity, which may cause damage to essential power systems and further exacerbate the situation. The power utility company thus purposely shut the power off in selected areas to balance the demand-supply levels. The shedding reduces the chances of more prolonged blackouts, avoiding complete shutdowns and avoiding damage to the power grid.
Various reasons lead to the need for power shedding. The primary factor is damage to the power transmission lines, which are the primary distribution lines, to different factors like storms, earthquakes, and vandalism of critical power equipment. Another reason is the loss of a significant power generator due to equipment loss or a primary contributor. For example, countries that rely on different sources of power, like power, nuclear or hydroelectric, may require shedding if severe drought affects the hydroelectric generators due to reduced water levels or a nuclear plant requires maintenance.
Also, load shedding becomes necessary if the consumers increase consumption in a limited time. An example is changing consumer behavior or requirements, such as population increase, heat waves, or winter, where people use heating, ventilation, and air condition systems more than on regular occasions.
When the highlighted scenarios occur, the national or local utility responsible for electricity transmission shuts down some power distribution and feeder lines to maintain short-term and long-term power integrity, reliability, and safety. In countries facing scenarios requiring shedding, these utility firms work with the governments for planned rollout plans, with prior notice to the affected consumers. This enables the involved parties to access services like automated teller machines and gas stations.
The consumers are grouped in clusters, and the power is switched off for a group for a few hours, typically two. After the scheduled hours, the operator switches the power off for the next cluster using the feeder lines while the first group resumes regular supply. The rollout cycle continues until the load shedding is complete and the system is stable. The rollout process is either automatic or manual. Operators prefer manual rollouts as they are more controllable and easily adjusted to suit different scenarios.
The government and utility companies often attempt to reduce the chances of and the need for rollout. The typical method was incentivizing industries and owners of large buildings to reduce power use during peak periods and off-grid options like solar systems.
However, in almost all instances, the operators ensure critical areas like hospitals, law enforcement areas, and water systems retain regular power supply, with most of the rollout directed to households. Shedding in these places can have negative consequences. An example is the Texas Power Crises, where experts indicated that over 700 people died from factors emanating from extended blackouts like freezing after a snowstorm cut off power. However, living near the critical areas does not guarantee exemption from the rollouts, as sharing the power feeder line is not assured.
The effects of the rollout vary, but the primary one is the inconvenience of intermittent power supply. When too frequent, like during the heavy rains and storm season, when damage to the power season is more frequent, people experience a reduced quality of life due to limited access to regular household, social, and economic activities. The goal, however, is to ensure a reliable power supply over a more extended period.