A (10) | B (1) | C (9) | D (15) | E (8) | F (3) | G (5) | H (3) | I (8) | K (2) | L (4) | M (11) | N (6) | O (3) | P (16) | R (5) | S (10) | T (5) | U (1) | W (6) | Z (1)
Term Definition
Reactive Power Support

This is the production of reactive power to maintain stability on the transmission system. Power on the system comes in two main types: the first is the power that is actually delivered to end users, and the second is reactive power, which is power provided to the system to maintain the system, rather than for end-use consumption.

Renewable Energy Credits (RECs)

The “green” or renewable attribute of electricity that is generated utilizing a renewable energy resource. A wind turbine that produces 1 MWh of electricity has produced 1 REC which, in some electricity markets, can be sold separately from the electrical power.

Renewable Portfolio Standard (RPS)/Renewable Electricity Standard (RES)

A minimum renewable energy requirement for a region's electricity mix. Under an RES, electricity suppliers are required to provide some percentage of its supply from renewable energy sources. RPS proposals frequently ease that requirement by including a tradable credit system under which electricity suppliers can meet the requirement by buying and selling renewable energy credits (RECs).


The process of changing the structure of the electric power industry from one of regulated monopoly over electrical customers to one of open competition between power producers for customers.

Rural Electrification Administration (REA)

An agency of the U.S. Dept. of Agriculture that makes loans to states and territories in the U.S. for rural electrification and for providing electricity to persons in rural areas who do not receive central station service. It also furnishes and improves electric and telephone service in rural areas, fosters energy conservation,on-grid and off-grid renewable energy systems, and studies the condition and progress of rural electrification.