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How to be green -- cars, electricity, farms


In light of my recent studies into transportation energy efficiency I've learned a lot more about the energy budget of the USA and the world.

One conclusion from those investigations is that if you are serious about greening the world, there are really only a few areas worthy of serious effort. Yes, you can make a difference anywhere, and if all you're going to make is a personal difference there are scores of things you can change in your life to reduce your own footprint. But if you want to make a real difference, by affecting groups of people and whole sectors, the choices are few and clear.


The footprint of cars and light trucks is so large -- 63% of transportation energy -- that I am tempted to say that if you're not working on cars, you're not working on being green. Freight trucks are another 17% of transportation energy. Transit is in the noise -- it only has bearing in that it can, in the rare cases it is done well, take people out of cars to make their travel greener. These numbers are huge, so of course differences can be made in the other transportation areas, but if the question of cars and trucks is not fixed, the rest of transportation barely matters in comparison. The one exception is jet airliners, which at 9% take the next largest shot of the energy budget.

However, transportation is "only" 28.5% of the total U.S. energy budget, so it's not quite the only place to go. However, adding the energy cost of manufacturing cars bumps them up to around a third.

Electricity Generation

The rest of the energy budget is split 32% industrial (including making cars,) 18% commercial and 21% residential. But 70% of residential energy, 78% of commercial energy and 34% of industrial energy comes from electricity. (Just .3% of transportation energy does, but that will change if we move to electric cars.)

All these energy uses are quite diverse. There are many targets to attack, all worthy within their own scope but there's only one truly big target, and that's electricity generation. In the USA that's currently 50% coal and 20% natural gas. So if you're working to fix this -- with renewable energy or nuclear -- then you're working on one of the big problems. Right now hydro and nuclear are the largest non-fossil power generators. All the other renewables are currently in the noise.


One of the biggest commercial users of energy is agriculture. It's estimated that the equivalent of 400 gallons of gasoline per person in the USA is used to grow our food. Part of that is that 5% of all natural gas goes into making fertilizer. This makes this a particularly large non-electrical target. In addition, most of the methane we emit comes from livestock. I need to do more research but currently agriculture looks like another big target.

So it's not quite true that if you're not working on cars, you're not working on being green, but it does suggest that projects like the Automotive X-Prize and DARPA Grand Challenge are among the most important projects in the world for going green.


How do you define residential use to get the 70% electricity? EIA 2001 gives this breakdown for total usage quadrillion BTU

Electricity: Primary 11.63, Site 3.89 (this uses 2001 generation mix, and those BTUs include nuclear BTUs at 20+% efficiency for the primary)
Natural gas: 4.84
Fuel Oil: 0.71
Kerosene: 0.05
LPG: 0.38
Wood: 0.37

Including nuclear and using primary I get only 64%, not 70%, and if I pull out nuclear (about 25% of the primary) it drops to 45%. I doubt that the ratios have changed much since 2001, although the totals have grown with the population.

I would also look at electricity use reduction, not just generation. Use reduction has a lot of leverage in terms of capital costs, maintenance costs, etc. on top of the fuel use reduction.

It's been growing. This DoE spreadsheet, table 2.2 of their fact book shows 69.5% of residential energy use being electrical (including losses involved in generating and transmitting electricity.)

As for use reduction, that's valuable, as must about anything is valuable, but this post is about what's really big. You can convince homes to reduce usage one house at a time. If you replace power plants, you make the big changes.

The differences between EIA 2001 and DoE 2006 need more detailed analysis. The DoE rate of change between 1973 and 2006 does not explain the difference. They must be using some rather different definitions. I'll stick with EIA because they do the very detailed breakdowns to the level of appliance types. Consistent definitions matter.

My experience has been that you do not get the major improvements until people are willing to change behavior. The first stage of "I won't change. You fix the problem. Make better power plants." is a kind of denial. During this phase you get only modest improvements.

That was my experience for air pollution and industrial energy use in the 1970's and 1980's. In air pollution denial meant adding scrubbers, etc. That "worked" but when they accepted that they would change the industrial process as part of air pollution control, the costs were 1/3 that of the addon controls and the pollution reduction was about 3x. Often, the integrated process changes both reduced product cost and air pollution. So during the 1980's the industrial air pollution sources shrank dramatically.

Similarly in the 1970's energy consumption was a "someone else" problem, despite the embargos, etc. In the early 1980's the industrial and commercial sectors accepted that behavior had to change, and the energy intensity of current industrial and commercial use is 25% of the 1980 level. Had this not happened, we would already be needing twice as many power plants.

The big sectoral differences are that industrial and commercial users have accountants and engineers. They have in place the data gathering and change design resources to respond to cost and use information with efficient behavior changes. It worked very well.

Government and residential users lack both accounting and engineering. They have a very hard time adapting effectively as a result. (There are government accountants, but government accounting systems routinely fail to gather anything useful.) The current difficulty in making government and residential energy use improvements is finding an effective alternative to the accountants and engineers.

Transportation is mixed. Corporate transportation (rail, air, etc.) have a fair to good history of energy intensity improvement. Government and private transportation has failed to improve much.

Nuclear has been on an indefinite hold in the U.S. for decades, with good reason. The reasons might not be good enough at this point, but that's another debate. Hydro has its own environmental problems, but there's no argument that it's as clean as power gets. However, there's not enough of it to go around.

IMO, all the other green alternatives for electricity have been hamstrung by insisting that it should be centralized generation that is both economical and profitable for the generator. In other words, the guys making money from selling electricity don't want to give up their control of the cash cow.

I think solar and wind power would have become more competitive much sooner if government had vigorously backed incentives for distributed generation. (We can also mention that distributed generation would go a long way toward solving the problems of security and widespread blackouts.)

Certainly we could have been incentivising alternative energy devices on all new construction since the first Arab oil embargo in the '70s. Our fetishization of the market has cost us valuable time. At this point, though, market forces will accomplish what good sense and foresight haven't for thirty-five years. The question will be, "Is it too late?"

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