A Primer in Keeping the Electric Grid Reliable

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Researched by Industrial Info Resources (Sugar Land, Texas)--Grid reliability is vital for maintaining a balance of electricity supply and demand at all times. To operate efficiently, power grids must have base-load, intermediate and peaking facilities.

Base-load power plants are the foundation of a reliable electrical system. They are usually nuclear or coal- or gas-fired plants that run continuously when not offline for maintenance and repairs. As base-load plants go down from time to time for planned or unplanned maintenance, they must have some sort of backup.

Intermediate power stations are able to change their output according to demand. These plants are able to supply additional electricity when needed, or store energy at night during times of low demand and releasing it when needed. A good example is a pumped-storage hydropower plant with upper and lower reservoirs. When power from the plant is needed, water stored in the upper reservoir is released into the lower reservoir, generating power along the way. When demand for electricity is low, the water is pumped back to the upper reservoir so that it will be available when needed.

Wind- and solar-generated electricity can be classified as intermediate, as their output fluctuates with weather patterns. These plants cannot be relied on to meet constant supply needs. These plants cannot start up right away to act as peaking facilities, but they can help reduce the need for fossil fuels and fill in the gap between base-load and peaking plants.

The peak-load plants, also known as "peakers," usually only run when there is a high demand for power. A peaker may operate only a few hours per day, depending on the condition of the electrical grid. Many peaking plants are gas-fired, as they can have a relatively quick startup time. Many peakers use oil as a backup fuel.

In the U.S., peak hours occur in the afternoon--especially in the summer months, when the air conditioning load is high, or in the evening hours, when appliances are in heavy use.

Industrial Info Resources (IIR), with global headquarters in Sugar Land, Texas, and eight offices outside of North America, is the leading provider of global market intelligence specializing in the industrial process, heavy manufacturing and energy markets. Industrial Info's quality-assurance philosophy, the Living Forward Reporting Principle™, provides up-to-the-minute intelligence on what's happening now, while constantly keeping track of future opportunities.