Explore this map to see where your electricity comes from!
Each dot represents an electric power plant, sized according to the amount of electrical energy it generated in either 2007 or 2016, and colored according to its primary energy source. You can zoom and pan the map, adjust the scale of the dots, and uncheck some types of power plants to focus on other types. You can also use the popup menu to scale the dots according to nameplate capacity or CO2 emissions.
Click or tap on any dot to see the data for that power plant (and a link to its location in Google Maps). Plant capacity is measured in megawatts (MW), or millions of watts. A typical American household uses electrical energy at an average rate of about 1000 watts, so a small 1-megawatt power plant can power about a thousand homes, while a large 1000-megawatt power plant can power about a million homes. A plant’s annual net generation is its average power output multiplied by the number of hours in a year (8760), and is measured in megawatt-hours (MWh). A plant’s capacity factor is its average output as a percentage of its nameplate capacity. Nuclear plants tend to have the highest capacity factors, followed by coal, gas, and hydro. The capacity factors of wind and solar plants are necessarily low because of the variability of wind and sunshine at any location.
This data is from the EPA’s eGRID databases for the years 2007 and 2016. Plants that produced no power (or negative net power) during the indicated year are not shown. As you can see, America’s electric power sector has been rapidly changing, with coal on the decline and gas, wind, and solar power on the rise. Further changes have occurred between the end of 2016 and the release of the eGRID 2016 database in February 2018. We’ll have to wait to see these changes in detail, but here is a graph of total U.S. electricity generation, by source, from 1950 through 2017:
The year 2007 was an approximate turning point for U.S. electricity, when total generation stopped increasing and gas, wind, and solar power began to replace coal.
Technical details: Some power plants obtain significant amounts of energy from more than one source, so the dot colors on the map can be somewhat misleading for these; the popup text will then indicate what percentage of the electricity was generated from the primary source. The vast majority of greenhouse gas emissions from power plants are carbon dioxide (CO2), but some plants emit other greenhouse gases as well, so CO2 equivalent, or CO2e, is used here. The “Other” category is defined in the eGRID documentation as “other unknown/purchased/waste heat”. Rooftop solar panels and other “behind-the-meter” generation are not included in the data shown on the map; the Energy Information Administration estimates that small-scale solar generation is about 50% as much as utility-scale solar generation.
This interactive map was partly inspired by a similar map by the Washington Post. The Post’s map is accompanied by some other nice graphics, but doesn’t have net generation data at the power plant level. Its dots are drawn according to capacity rather than net generation, so I think it’s a little misleading about the relative importance of different energy sources. Many other similar maps have appeared over the years, but the eGRID data seems to be the best source for this type of visualization.
Of related interest, here is a summary of total U.S. electricity generation and primary energy use, with historical charts.
Created by Daniel V. Schroeder, Physics Department, Weber State University.
This interactive map uses my personal Mapbox free “starter” account, which has a limit of 50,000 map views per month. I'm not sure what constitutes a map view or how likely it is that the limit will be reached. Please contact me if you encounter difficulties.