4m. Meeting Daily Electricity Demand
The demand for electricity doesn’t remain constant, but instead peaks and falls in a predictable pattern. Grid operators have identified daily, weekly and seasonal patterns in electricity use. Recognizing these patterns helps electrical providers ramp up or slow down generation accordingly.
Base demand describes the amount of electricity that is required at all times. Plants such as coal-fired plants work well for meeting base demand. The cost of starting up a coal-fired plant is high, but once it is running, the cost to continue producing electricity is relatively low.
During peak times, the price of electricity generally rises as more responsive types of power plants are brought online. Natural gas power plants can fire up quickly to meet peak demands, but cost more to operate when gas prices are high. This can lead to higher electricity prices for ‘on-peak’ pricing.
Daily Patterns
Overnight, electrical demand falls as the majority of people sleep and businesses and industries are closed. Over the course of the morning, electricity requirements begin to build and reach peak demand during the afternoon hours. As businesses, schools, and industries close for the day, electrical demand begins to fall.
Weekly Patterns
Between 10:00pm and 7:00am on weekends, electrical demand is low. These are referred to as ‘off-peak’ hours.
Seasonal Patterns
The high and low temperatures of winter and summer drive electrical demand up as furnaces and air conditioners are used more regularly. Electrical demands during spring and summer are typically much lower.
