Sometimes looking at the big picture is the best way to understand what’s going on.
That’s definitely the case for figuring out where the world’s energy comes from and goes. Lawrence Livermore National Laboratory makes these energy flow maps showing where energy comes from and how this energy is used for each country and the world as a whole.
This information can be really useful when we are trying to pin down ways to slow climate change. Since you can see where the biggest bubbles are in the pipeline, you can see where we need to cut down. And, looking at how skinny the renewable energy sources’ lines are, where we need to bulk up.
In 2011, the world used 534,000 petajoules (PJ) of energy, and the biggest source of that energy was oil, unsurprisingly, at 60%. For context, the average American home used 39 billion Joules of electricity in 2013; a petajoule is equal to 1,000 trillion joules.
Here’s how the world’s energy flow breaks down:
This chart is overwhelming at first, but not so bad once you look at it closely. Where all of the energy comes from is on the left and where it all goes is on the right. Follow the coloured lines that emanate from the sources to figure out where that energy is going:
A few interesting things to note.
The world’s biggest energy-guzzling sector is industry, with transportation close behind. What’s particularly interesting is that transportation — that’s our planes, trains and automobiles — is the biggest user of petroleum, which is terrible for the environment. As Elon Musk told Wait But Why, a switch to electric cars could have a huge impact on fossil fuel emissions.
The most frustrating thing about this chart, though, (besides how little energy renewables are putting into the system) is this grey box on the far right.
In 2011, more energy was wasted than used. The “rejected energy,” at 290,000 PJ, is what was lost because we can’t use energy sources with 100% efficiency. A lot of this energy was lost as heat during the fuel-burning process. The transportation sector, for example, is only 25% efficient.
“Not all of the energy that we consume is put to use,” A.J. Simon, group leader for Energy at Lawrence Livermore, said in a press release. “Heat you feel when you put your hand on your water heater and the warm exhaust from your car’s tailpipe are examples of rejected energy.”
If we could capture the energy we use more efficiently, we could ultimately use less of it. That would do wonders for the environment. And to generate all of the energy that the rapidly growing human population will need without destroying the planet, we’re also going to have to get a lot more of it from renewable sources.
But it’s tough to truly realise what’s going wrong without seeing what’s really going on.
We found these graphics in Tim Urban’s “How Tesla Will Change The World” post at Wait But Why, which is really long but worth a read.