The fixed cost of all facilities in the power supply system, including generating plants, substations and distribution lines.

Brokers who seek to bring together customers to create a “load” so that they can buy power in bulk, making a profit on the sale.

An electric current that reverses direction of flow at regular intervals and has alternately positive and negative values.

Fish (such as salmon and steelhead) that hatch in freshwater, migrate to the ocean, mature there, and return to freshwater to spawn.

Includes the provision of reactive power, frequency control and load following.

Regulation of the power output of electric generators within a control area in response to changes in load, system frequency and other factors, to maintain the scheduled system frequency and interchanges with other control areas.

A unit of energy output over a year that is equal to the energy produced by the continuous operation of one megawatt of capacity over a period of time. (Equal to 8,760 megawatt-hours).

A pricing mechanism based on dividing the total cost of providing electricity incurred in a period by the number of units sold in the same period.

The cost of a utility’s generation and transmission system. Under the Residential Exchange provisions of the Northwest Power Act, a utility may sell power to BPA at the utility’s average system cost and purchase the same amount of power back from BPA at a rate based on the costs of the Federal Base System.

A guideline for comparing the value of conservation and renewable resources with other resources. Literally, the cost a utility avoids by purchasing a conservation or renewable resource versus acquiring energy elsewhere.