A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

Improved Recovery - The operation whereby crude oil or natural gas is recovered using any method other than those that rely primarily on the use of natural reservoir pressure, gas lift, or a pump.

Incandescent Lamp - Electric lamp in which an electric current heats a filament until it emits light.

Independent Power Producer - An IPP generates power, which is then purchased at wholesale price by the electric utility. The utility then resells the electricity to end-use customers.

Intangible Drilling and Development Costs (IDC) - Costs incurred in preparing well locations, drilling and deepening wells, and preparing wells for initial production up through the point of installing control valves. None of these functions, because of their nature, have salvage value. Such costs would include labor, transportation, consumable supplies, drilling tool rentals, site clearance, and similar costs.

Interruptible Service/Interruptible Supply - Power supplied under agreements that allow the supplier to curtail service at times.

Investment and Advances to Unconsolidated Affiliates - The balance sheet account representing the cost of investments and advances to unconsolidated affiliates. Generally, affiliates that are less than 50 percent owned by a company may not be consolidated into the company's financial statements.

ISDN - The Integrated Services Digital Network is a 128 Kbps digital service.

ISO - An Independent System Operator is a 'neutral' operator responsible for maintaining instantaneous balance of the grid system.