Big Ideas Lab podcast traces the flow of energy in the U.S.

Inside a sixth-grade classroom, a teacher dims the lights and directs the student's attention to a projector. On the screen appears a brightly colored chart featuring thick, twisting bars extending from left to right. Some are as wide as rivers; others as narrow as threads.

The diagrams look almost like a subway map for America’s energy. At the left, the lines “depart” from their sources — oil wells, wind farms, solar fields and gas pipelines. As they move across the screen, the bands split, merge and branch, just like train lines at a crowded station. Some peel off into electricity generation, others flow straight into transportation, factories or homes. And at the far edge, every line arrives at one of two final stops: energy we actually use or the gray box of waste.

A few kids lean forward. For the first time, they can see energy: where it comes from, where it goes and how much of it disappears along the way. These are energy flow charts.

Learn how scientists at Lawrence Livermore National Laboratory (LLNL) trace energy’s path from generation to end-use in the latest episode of the Big Ideas Lab, available on Apple and Spotify.

Hundreds of miles away from this classroom, in Washington, D.C., analysts are leaning forward in front of the exact same charts. They’ve waited all year for the vital information they provide to decide how secure the nation is, and where to take action.

“That is why Lawrence Livermore National Laboratory was tasked with [the energy flow charts]. Because for a nation to be secure, you really need to be secure in your energy infrastructure, as well as your energy resources that power it,” said LLNL research scientist Kimberly Mayfield.

From lessons in a classroom to decisions in the capitol, the truth behind dependence, tradeoffs and innovation is revealed through the energy flow charts.

“The Lab started creating them in 1970, around when the oil crisis was happening,” said Hannah Goldstein, the system and policy analysis group leader at LLNL. “They used to be hand-drawn.”

Since then, the charts have evolved. But some things haven’t changed: their power is in their restraint. No jargon. No thousand-page report. Just a picture you can read in seconds that shows where energy comes from, where it goes and how much is lost.

Find out more about the science behind the simplicity in the latest episode of the Big Ideas Lab, available on Apple and Spotify.