System load
The amount of power on PGE’s distribution system needed to serve all of our customers’ needs at a particular time. At PGE, we buy a portion of our power on the open market. When there is a high demand, or heavy system load, we buy more power, and the prices are higher. By shifting energy use to off-peak hours, Time of Use customers lighten the system load.

Demand
The rate at which electric energy is delivered by PGE’s system at a given time. During on-peak hours, demand is high and electricity is more expensive.

Steady load
The constant amount of power a household requires. In other words, the power needed for things that are always on, like your refrigerator.

Batch load
The variable amount of power a household requires, such as the energy needed to run the dishwasher, washing machine, water heater, TV and other appliances.

On-peak
When electricity is in high demand and you pay the highest price per kilowatt-hour.

Mid-peak
When demand for electricity is between on-peak and off-peak.

Off-peak
When the demand for electricity is the lowest and you pay the lowest price per kilowatt-hour.