Energy Literacy part One: Energy is invisible

Saul Griffith is an inventor and entrepreneur. He did his PhD at MIT in programmable matter, exploring the relationship between bits and atoms, or information and materials. Since leaving MIT, he has co-founded a number of technology companies including,,,, and

You might have just driven home. When you filled your car with gasoline, most likely you didn't even see the fluid as it was pumped into your gas tank. Once home, you probably turned on some lights, some music, your computer, and maybe even heat, so you could read this web page. You can't see the power running through the electrical lines that lead to your light bulb, and you don't feel it, but you do enjoy the results. Our society has made energy invisible. This invisibility makes energy convenient to use -- and the modern age is arguably wonderful as a result -- but it also makes it easy to take it for granted. Here we try to make our appetite for energy visible.

Climate change is a phenomenon we now recognize as one of the most important challenges to ever confront humanity. Like energy use, it is also mostly invisible to us, and in two important ways.  Firstly, the enormous volumes of green-house gases -- carbon dioxide, methane, CFC's etc, are quite literally invisible to our naked eyes. Secondly, the changes in climate progress so slowly that they seem invisible amidst the hustle and bustle of our daily lives. Because these consequences accumulate over decades, generations, and centuries, it is easy to not see them as pressing and urgent. Here we try to make visible these complicated and largely invisible things.

The global energy and climate conversation is about choices, both individual choices and collective choices. By choosing the amount and type of energy we consume, we are choosing the look and feel of our future. Everyone is involved in that choice. Don't be fooled: individual choices collectively have enormous effects.   A large coal power plant has a power output of 1GW (GigaWatt) which is 1 billion (1 000 000 000) Watts.  If 1 billion people reduced their power needs by just 1 watt ( About what is required to keep a compact fluorescent burning for just 1 hour a day), that's a coal fired power plant you don't need to build.  

This material tries to help you make those choices in a more informed manner. We also hope this material influences the governments, organizations and corporations who make the decisions about our energy future on a macro level.

These posts are about energy, climate change, finite resources, and the future. Unfortunately, the creation of this material is implicated in the very climate change and energy challenges we wish to avoid. You chose to read this, which means you chose to use some energy. These posts are not "carbon free" or "carbon neutral". At the time of its publishing there was practically no way that it ever could have been. Nearly every choice you make involves energy and all those choices have implications for the environment.

Two people wrote this stuff. We both ate food produced by modern industrial agriculture to power ourselves while writing. We used at least five computers at different times to do the calculations, write the words, and edit the layout. After we had done our work, editors and designers used computers to further refine the text and images. Each of those computers ran for many hours, consuming somewhere between 20 and 200 watts of power each as they did so. The computers themselves were made in factories in China and Japan with chips produced in the United States, and cases probably made from bauxite mined in Australia and processed in Argentina.

If you print this out, the paper it is printed on was probably made from trees that were cut down in Canada. The chainsaws that cut the trees ran on two-stroke gasoline. The trees were lifted onto a truck with a crane powered by diesel fuel. The truck drove the trees to the sawmill using diesel. Before the trees from which these pages were made had even been pulped, three internal combustion engines had been fired up, burned a fossil fuel and emitted some carbon dioxide. How much CO2? Not a lot. But all the little pieces add up.

If you are just reading this on the web, there are disks and processors in data centers in numerous places running from coal plants, gas plants, even hydro and solar plants where the production of the cement and silicon was itself done using fossil fuels. The point is, it's a really complex system.

As these paragraphs show, the global supply chain for energy is complex. This was in small part inspired by the pamphlet "I, Pencil - My Family Tree as told to Leonard E. Read." (1958). A piece that highlights just how interconnected our modern world is.


We fill our cars with gas regularly, but don't even see the liquid go into the tank. If we were to imagine that we had to fill a backpack with the fuels required for a day of our lives, what would we be filling our energy back-pack with each day?

Each day the average American sets out with:

OIL = 10.81 L/Person/day (2.9Gallons)

COAL = 9.54 kg/person/day (21 pounds)

NATURAL GAS = 5.88 m^3/person/day (208 cubic feet)

Which roughly converted to those other units is around 22 Pints of oil per day (one per hour!), 21 pounds of coal (another per hour) and 200 cubic feet of natural gas.

I used the annual consumption of coal and natural gas, and the daily consumption of oil, and converted it to the daily average by dividing it out by the population of the US.

The data is here.



  1. If only Tesla had his way then energy wouldn’t be invisible… we’d have totally awesome lightning bolts EVERYWHERE!

  2. don’t forget viktor schauberger and all the others over at rexresearch.
    energy wants to be free and clean, global warming is bunk! can you say tax scam?

  3. I’ve just invested in an induction hob a new frontier for me
    there are remarkable value gained in how I boil water
    let alone how and what type of food I prepare
    for example it takes 50% less time now to cook rice


  4. >1 watt ( About what is required to keep a compact fluorescent burning for just 1 hour a day),

    I bet you intend to say ten watts, and might want to correct the typo. Alternatively, you might let me know who sells those 1 watt compact fluorescents.

    1. Yeah, I didn’t get that either. Surely a measure of energy (kilowatt hours, for example) is intended, and not power? Or does it mean decreasing average consumption by 1 watt, which would be equivalent to a 24 watt bulb 1 hour a day (1/24th of the time)?

  5. Energy is invisible because it does not physically exist.

    Gasoline exists, and electricity (sort of) exists, and heat (sort of) exists, and you can conveniently do theoretical work involving an arbitrarily designated common characteristic of these by postulating a synthetic attribute and assigning it unit values that are useful for your work.

    Energy is like truth; it has agreed-upon values, but it has no physical existence without embodiment in some other discrete physicality.

    I’m probably not expressing this well.

    Ed Abbey said, in reply to Plato, “I seen a horse, and I seen a cow, but I ain’t seen none of this here horsiness nor bovinity neither”.

  6. The article starts out unconvincing because it fails to demonstrate basic energy literacy. Watts are units of power, an instantaneous quantity.

    Electrical energy consumption is measured in average kilowatts of power multiplied by hours it is consumed. 100 watts x 5 hours = 500 watt-hours = 0.5 kilowatt-hours.

    A wall-wart, or string of Xmas lights, consuming 5 watts for 24 hours will consume 120 wH or 0.12 kWh … the same amount of energy as a 1000-watt toaster used for 7.2 minutes.

    A compact fluorescent using 15 watts for an hour will consume 0.015 kWh … not “1 watt” as the article states.

    If one person decreases their average power use by 1 watt, they’ll save 0.024 kWh per day. If 1 billion people do this, they’ll save about 24 million kWh per day.

    The average American home consumed about 9000 kWh in the year 2000. That one day of a billion people saving 1 watt would power 2,600 American homes for a year. And a helluva lot *more* homes almost everywhere else in the world. (There are one or two countries -even more wasteful- than we are, believe it or not.)

  7. The paragraph about the 1GW coal plant and the amount of avoided energy consumption needed to offset the building of a coal plant is a bit of an oversimplification, but in all its a pretty useful illustration of the benefits of energy efficiency.
    To make the calculation a bit more accurate, you may want to take into account the line losses associated with the delivery of that 1GW of power to consumers (over Transmission and Distribution wires). Line losses vary, but are typically in the 8-10% range. So in order to deliver 1GW of electricity, the plant actually has to produce about 1.1GW. The other way to look at that is that only 900,000,000 people need to reduce consumption by 1W (instead of a full billion).
    In the context of such large numbers anyways, 10% may not seem like much, but increasing the size of a power plants output by 100MW is not a trivial matter either in terms of cost or emissions.

  8. So 1 billion people giving up a light for 1 hour a day will cancel 1 power-plant. That would mean that the whole population of the earth (6.7 billion) giving up a light for a whole day will only prevent the need for 160 coal fired power plants. Now if only I could find the figures for how many coal fired powerplants there are in the world, this would mean a lot more.

    nutbastard – to pick the first hole that comes to mind, that data doesn’t seem to take in to account that a lot of the existing greenhouse gases in the atmosphere actually provide useful benefits, and that it is the increase that is causing problems. Is it suprising that the combined green house gases in the entire atmosphere is far greater than the ones we have added to it. No. Does that relate to the effect caused by what we are doing. No.

  9. So if we could get everyone in the world to cut their energy use by one watt a day we could close down six coal fired plants.

    Building six nuclear plants accomplishes the same amount of CO2 reduction and takes a heckuva lot less persuasion.

  10. Here’s what I’ve done to make my energy visible: I don’t drive my car anymore. It’s a nice car, a ’91 Nissan 240sx. Very fun car, especially with rear wheel drive, four wheel steering, and a kickin’ stereo system. Ya want it? Check my local craigslist when I get around to cleaning it up and selling it.

    Instead I ride my bike(s). Constantly. Incessantly. To the tune of 4029 miles so far this year. (But hey, who‘s counting, right?)

    I tell you this, it has given me perspective on power. Speed and distance, too. I estimate that when I go to work in the morning, I’m putting out 150+ watts for about seventeen minutes. Five miles are short enough that I can do it without breakfast some days, but it moves my hunger point up by two hours. When I do thirty or more miles I need a solid meal within three hours beforehand and additional sugars within twenty miles.

    Now, to convert these power numbers, which I feel oh so acutely, over to kWh, that’s just humbling. I keep a pair of grow lights pointing at the cinder blocks to the left of my desk so the windowless office doesn’t kill me and/or my coworkers. The combined mileage of a round trip to work and a ten to fifteen mile grocery run later in the evening doesn’t represent enough energy to keep those bulbs lit past lunchtime… which was two hours early today because I skipped breakfast.

  11. Please learn the difference between a watt and a watt-hr. You can’t “save” watts any more than you can “save” miles per hour. You can reduce your demand by a watt, which will save 24 watt-hrs per day.

    1. @Anon: No one said that anyone would “save” a watt, so I don’t know where the quotation marks come from.

      Rather, the article discusses reducing your power needs by a watt (in the same way that switching from a 60W bulb to a 12W bulb reduces your power needs by 48 watts), and someone else in the comments mentioned saving some number of kWH, which, as a measure of energy, can certainly be saved.

      Who were you talking to anyway?

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