Emissions Comparison of Alternative Energy Sources

We live in exciting times. There are a lot of alternative fuels and power sources out there for everything from powering the lights in your house to the vehicle you drive down the road. In addition to our traditional gasoline and diesel fuels we now have different levels of ethanol and biodiesel; not to mention hybrids and plug in electrics. To make things more confusing each alternative has its own benefits and pitfalls, and the information you find on the web is often slanted to promote someone’s agenda. At times it’s like competing religious sects.

Our government is in the process of studying all the various alternatives, but with almost daily innovations and advancements in technology, it gets a little bewildering.

Perhaps the most studied fuel is biodiesel, so let’s start there.

Most things in life are a trade off; with a biodiesel powered vehicle you produce less carbon emissions at the cost more soot and a few other negatives. So let’s examine the numbers here:chart

According to this chart from a report done by the EPA in 2001 the addition of biodiesel to petroleum diesels dramatically decreases Carbon Monoxide, Particulate Matter, and Hydro-Carbons, but a slight increase is seen in Nitrogen Oxide. According to the EPA:

NOx causes a wide variety of health and environmental impacts because of various compounds and derivatives in the family of nitrogen oxides, including nitrogen dioxide, nitric acid, nitrous oxide, nitrates, and nitric oxide.

Which mean:

  • Ground-level Ozone (Smog)

  • Acid Rain

  • Particles

  • Water Quality Deterioration

  • Climate Change

  • Toxic Chemicals

  • Visibility Impairment

So obviously this is something to be concerned about; keep in mind, however, that this is only a small increase in the amount of Nitrogen Oxide as compared to regular diesel. The dramatic decreases in the other harmful elements generally mean that biodiesel is a win over the Dino based diesels.

But how does biodiesel stack up to our other alternatives? That’s not an easy question to answer. It is more or less simple to compare a diesel vehicle running petroleum diesel to one running bio. Simply test the same vehicle with both fuels and do the math. (it’s more complicated than that, really…but not by much). Just buy a vehicle that can be ordered with either an E85 or a diesel power plant; well, I haven’t found that car yet.

So what we have to go with is generalizations. Not the hard science that I would like to have available, but we do with what we have. And the closest I came to a comprehensive comparison was a report done by Ford and Harvard that produced the following charts. The electric car stats assume a traditional electrical infrastructure.


Keep in mind this study was done in 2001 and advances in both E85, Electric and Diesel motors have been significant in the last few years. The issue is further complicated by the fact that cleanest diesel motors are also not approved by the manufacturer to run biodiesel.

The bottom line is that Biodiesel, E85, Hybrids…All are an improvement over regual gas or diesel these days. It does no good, though, to buy an E85 car in an area where there is no E85 infrastructure and in some ways it does more harm than good to buy a diesel if you don’t live near a biodiesel station (or don’t make your own). Find the car that matches your needs and keep in mind that a few years down the road there will be a new big thing. But you can sleep at night knowing that you did something other than wait and see.

2 thoughts on “Emissions Comparison of Alternative Energy Sources”

  1. Where did you get the data for the table? What are the unit? How do you compile them? Thank you.

  2. Are the charts (GHG Emissions/Mile for a Passenger Car, and, Grams CO2 equivalent/mile) listed in PPM or as percentages?

    Thank you!

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