Supply, demand and pricing

When developing the time periods for our Time of Use program, we used our system load — the demand patterns of our customers — as a guide to create the on-peak, mid-peak and off-peak periods.

It’s virtually impossible to store large amounts of electricity. It must be produced exactly when people need it. So power producers must build enough power plants to meet demand at all times — both in the middle of the night when power use goes down, and around the breakfast and dinner hours when overall power consumption rises substantially.

Most of the new power plants built today burn fossil fuels, contributing to air pollution. By reducing peak-hour energy use, you can help delay the need for new power plants in the Northwest. When everyone uses power at the same time, such as mornings and evenings, PGE must use additional resources to meet the demand.

By shifting your energy use away from on-peak and mid-peak periods, you’re doing your part to reduce the overall power demand in the region.

Resource generation
PGE meets our area’s growing energy demands with a diverse mix of low-cost generation facilities that includes water power, coal and gas combustion. Our renewable power customers also receive a mix of geothermal and wind power. Our eight hydroelectric plants and five thermal plants have a total combined generating capacity of 2,022 megawatts.

PGE also owns major transmission rights to the Pacific Intertie, the West Coast electrical superhighway. These power exchange lines give us the flexibility to buy power from other utilities and power generators.

Less than half of our load is generated by our own power stations. The rest is purchased from other energy suppliers on the open market. PGE was the first utility in the U.S. to open our own trading floor — buying and selling power to meet our customer needs efficiently.

We obtain the least expensive power first, using the most expensive power as a last resort from quickly starting “peaking” plants. These are plants that meet increased, or “peak,” demand for short periods of time. If we reduce the overall peak consumption by reducing demand at these periods in the day, we do not need to access the more expensive peaking plants for short bursts of energy or buy from other generators. We flatten our load curve, reduce costs, and don’t have to pay high prices on the spot market if we have to meet demand quickly.

Time of Use customers help us reduce our overall system demand during high-peak hours because the Time of Use peak periods directly match those of the overall system load. The On-Peak periods match the hours of the day when overall system demand is high. By shifting as much energy as possible away from On-Peak and Mid-Peak, you not only save money but you also help reduce the need for PGE to buy expensive short-term power from peaking plants to meet that need.