What Is Demand:

Demand is the independent variable in the electric industry. Demand forecast information is a critical part of ensuring that a load-serving entity is resource adequate. New generation resources or more energy purchases will be needed to meet demand if demand is expected to grow. Analyzing historical trends can help determine what the forecast should be. There are two types of demand important to resource planning.

Annual Demand: The amount of energy in MWh needed to serve an area over an entire year. It is typically divided into seasons because demand cycles are closely related to weather and seasonal patterns. Understanding annual demand and its seasonal changes help in planning a resource portfolio.

Peak Hour Demand: The amount of power in MW needed to serve an area during the peak hour of the day or year. Understanding trends in peak hour demand helps to identify changes that must be considered in resource planning. Note that when the map is selecting all of the interconnection, the peak demand is a summation of all of the areas peak demands even though they may not fall on the same hour. This is called a non-coincidental peak demand.

Page Tips:

By selecting separate regions from the map, you can see specific trends associated with the different sub-regions within the Western Interconnection. Different combinations of BAs can be selected from the drop-down chart.

Note: When a sub-region is selected from the map, the list of BAs in the drop-down list corresponds to the BAs in that region. If there are selections in the BA list, only the regions of the map with a BA in the list are selectable.

To reset the map, select the highlighted region a second time. To reset the BA list, either “x out” of the BA(s) selected or hit the eraser button.