U.S. Energy Information Administration - EIA - Independent Statistics and Analysis
Frequently Asked Questions
What is the difference between electricity generation capacity and electricity generation?
Capacity is the maximum electric output an electricity generator can produce under specific conditions. Nameplate capacity is determined by the generator's manufacturer and indicates the maximum output of electricity a generator can produce without exceeding design thermal limits.
Net summer capacity and net winter capacity are typically determined by a performance test and indicate the maximum electricity load a generator can support at the point of interconnection with the electricity transmission and distribution system during the respective season. There are two primary factors that affect or determine the difference in capacity between summer and winter months:
- The temperature of cooling water for thermal power plants or the temperature of the ambient air for combustion turbines
- The water flow and reservoir storage characteristics for hydropower plants
Generation is the amount of electricity a generator produces over a specific period of time. For example, a generator with 1 megawatt (MW) capacity that operates at that capacity consistently for one hour will produce 1 megawatthour (MWh) of electricity. If the generator operates at only half that capacity for one hour, it will produce 0.5 MWh of electricity. Many generators do not operate at their full capacity all the time. A generator's output may vary according to conditions at the power plant, fuel costs, and/or as instructed by the electric power grid operator.
Net generation is the amount of gross electricity generation a generator produces minus the electricity used to operate the power plant. These electricity uses include fuel handling equipment, water pumps, combustion and cooling air fans, pollution control equipment, and other electricity needs.
Data on electric power plants generating capacity
Data on electricity generation and thermal output
Existing nameplate and net summer capacity by state, type of producer, and energy source (historical data file from1990 to most recent year available)
Net generation by state, type of producer, and energy source (historical data file from1990 to most recent year available)
Last updated: February 23, 2016
Other FAQs about Electricity
- Can electric utility customers choose their electricity supplier?
- Does EIA have county-level energy production data?
- Does EIA have data on each power plant in the United States?
- Does EIA have data on the costs for electricity transmission and distribution?
- Does EIA have energy consumption and price data for cities, counties, or by zip code?
- Does EIA have maps or information on the location of electric power plants and transmission lines in the United States?
- Does EIA have projections for energy production, consumption, and prices for individual states?
- Does EIA publish data on peak or hourly electricity generation, demand, and prices?
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- How is electricity used in U.S. homes?
- How many nuclear power plants are in the United States, and where are they located?
- How many power plants are there in the United States?
- How many smart meters are installed in the United States, and who has them?
- How much coal, natural gas, or petroleum is used to generate a kilowatthour of electricity?
- How much does it cost to build different types of power plants in the United States?
- How much does it cost to generate electricity with different types of power plants?
- How much electricity does a nuclear power plant generate?
- How much electricity does an American home use?
- How much electricity is lost in transmission and distribution in the United States?
- How much electricity is used for lighting in the United States?
- How much energy is consumed in the world by each energy end-use sector?
- How much of U.S. carbon dioxide emissions are associated with electricity generation?
- How much of world energy consumption and production is from renewable energy?
- What is U.S. electricity generation by energy source?
- What is the difference between electricity generation capacity and electricity generation?
- What is the efficiency of different types of power plants?
- What is the outlook for home heating fuel prices this winter?
- What types and amounts of energy are produced in each state?