The power coming through your electrical socket is undergoing the fastest, largest change in American history.

The Atlantic's Alexis Madrigal in conversation with industry entrepreneurs shaping our future. See full coverage

You may not have noticed, but there is something happening to the American electricity supply that we've never seen before. Not in 1973 or 1950 or even in 1900. As long as Americans have made electricity, they've gotten more of it from coal than from any fuel. While petroleum and natural gas have played huge roles in our energy system, coal's been responsible for more than 65 percent of the fossil-fuel electricity we've generated for most of the last 50 years. (And for big chunks of the 20th century, we made half of all the electricity in this country by burning coal.)

But natural gas is in the process of overtaking coal as the top fuel in America -- and fast. The energy system, as you can see in the chart, tends to change slowly. But just look at the last three years in the chart below. That's the kind of growth that you tend to see in the high tech industry, not energy. That's an honest-to-goodness hockey stick.