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Mercedes Station Wagon

Not quite the same car, but you get the idea

The first car I ever drove was a 1982 Mercedes station wagon.  It was a beast: big as a boat and  rumbly with diesel power.  But it was expensive to maintain, and my mom eventually sold it to my godfather, Bill, when I was still pretty young.  And I was amazed to learn that he ran it off leftover restaurant grease.  That’s not diesel…right?

Enter the new world of diesel: biodiesel.  Made out of soybean oil, canola oil, or just leftover cooking grease, biodiesel is a renewable energy source that, like ethanol, can be blended with regular diesel or used on its own.

But biodiesel has some unique properties that are very encouraging for those looking to reduce oil dependence and greenhouse gases (and that’s all of us, right?).

  • Biodiesel can be used in normal diesel engines with little or no modifications to the car itself
  • Biodiesel reduces CO2 emissions by almost 80% from regular diesel emissions
  • Biodiesel can be made at home without lots of fancy equipment or extensive chem knowledge.  Take a hint from godfather Bill!
  • Emissions of just about everything (particulate matter, carbon monoxide, you name it) are reduced when using biodiesel.

So what are the downsides?  First off, diesel has a pretty bad rap (think choking black fumes spewing from an 18-wheeler).  Some people are just scared off by the word diesel, so convincing the public that biodiesel isn’t so bad might be hard.  And while biodiesel is getting cheaper (and has been deemed the most cost-effective diesel alternative), it may still be a little pricier than diesel.  Also, biodiesel can be tricky to find, although it is becoming more widely available.


Finally, something from McD's that is good for you!

Of course, you could always just go to your nearest McDonald’s and bring home some leftover Big Mac grease.

For a time, ethanol was billed as the solution to our fossil fuel addiction.  It’s renewable, it emits less CO2, and it’s made from common crops.  What could be better, right?

If only it were that easy.


It's in just about everything we eat, and now it's in our fuel, too!

Let’s start with the good stuff.  Ethanol is commonly made from corn, but researchers are working to produce it from other plants, like switchgrass.  That means ethanol is made right here in the good old US of A, which reduces our dependence on foreign oil.  Since it’s made of plants, which take in CO2 from the atmosphere, it helps reduce greenhouse gases.  And burning ethanol itself reduces less air pollution and greenhouse  gases than burning gasoline.  Pretty slick.

But alas, the course of searching for cleaner cars never did run smooth.  Ethanol has some pretty major downfalls.

  • It’s not widely available outside the Midwest.  To make ethanol more accessible, you have to transport it, which might not be the cheapest or most environmentally friendly answer.
  • Ethanol contains less energy than gasoline, meaning fewer miles to the gallon.
  • Prices fluctuate depending on crop prices.
  • While the plants that go into ethanol do take in carbon dioxide, the equipment used to produce and process those plants emit CO2, and the specific balance of these two processes is unclear.
  • Some researches believe that ethanol takes more energy to produce than can be obtained from the fuel itself, although this has been refuted in a UC Berkeley study.

So what is the verdict?  While we may not be as excited about ethanol as we used to be, it is certainly still a part of the renewable fuel solution.  Many gas stations sell gasoline that contains about 10% ethanol.  And researchers are working hard to produce commercial ethanol made from cellulosic materials like corncobs and other inedible plant parts.  This is one technology that seems here to stay, at least for now.

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August 2020