I
- Identified Resources
- Idle Capacity
- Impedance (Z)
- Implicit Price Deflator
- Implied Heat Rate
- Imported Crude Oil Burned as Fuel
- Imported Refiners' Acquisition Cost (IRAC)
- Imports
- Improved Recovery
- In Situ Leach Mining (ISL)
- In-house Demand-Side Management (DSM) Program Sponsor
- In-Use Vehicles
- Inadvertent Power Exchange
- Incandescent Lamp
- Incandescent Light Bulbs
- Incentives Demand-Side Management (DSM) Program Assistance
- Incremental Effects
- Incremental Energy Costs
- Independent Power Producer (IPP)
- Independent Power Producer (IPP)
- Independent System Operator (ISO)
- Indian Coal Lease
- Indicated Reserves
- Indicated Resources, Coal
- Indirect Cost
- Indirect Uses (End-Use Category)
- Indirect Utility Cost
- Industrial Production
- Industrial Restrictions (Coal)
- Industrial Sector
- Inferred Reserve Base (Coal)
- Inferred Resources
- Initial Enrichment
- Initial Operation
- Inoperable Capacity
- Installed Nameplate Capacity
- Instantaneous Peak Demand
- Instantaneous Water Heater
- Institutional Living Quarters
- Insulation
- Insulation Around Heating and/or Cooling Ducts
- Insulation Around Hot-Water Pipes
- Insulation Around Water Heater
- Insulator
- Intangible Drilling and Development Costs (IDC)
- Integral Collector Storage (ICS)
- Integrated Demand
- Integrated Gasification-Combined Cycle Technology (IGCC)
- Intensity
- Intensity Per Hour (IPH)
- Interburden
- Interchange (Electric)
- Interchange Authority (Electric)
- Interchange Energy
- Interchange Transaction (Electric)
- Intercity Bus
- Interconnected System
- Interconnection
- Interdepartmental Sales
- Interdepartmental Service (Electric)
- Interest Coverage Ratio (ICR)
- Intergovernmental Panel on Climate Change (IPCC)
- Interlocking Directorates
- Intermediate Grade Gasoline
- Intermediate Load (Electric System)
- Intermittent Electric Generator
- Internal Collector Storage (ICS)
- Internal Combustion Engine (ICE)
- Internal Combustion Plant
- International Bunker Fuels
- International Energy Agency (IEA)
- International Organization for Standardization (ISO)
- International System of Units (SI)
- Interruptible Gas
- Interruptible Load
- Interruptible Load (Electric)
- Interruptible or Curtailable Rate
- Interruptible Power
- Interstate Companies
- Interstate Pipeline
- Interstate Pipeline Purchase
- Intransit Deliveries
- Intransit Receipts
- Intrastate Companies
- Intrastate Pipeline
- Investment of Municipality
- Investments and Advances to Unconsolidated Affiliates
- Investor-Owned Utility (IOU)
- Investor-Owned Utility (IOU)
- Ion Exchange
- Iron and Steel Industry
- Irradiated Nuclear Fuel
- Isobutane
- Isobutylene
- Isohexane
- Isomerization
- Isopach
- Isopentane
- Isotopes