Watermelon: Picnic Treat & Source of Renewable Energy

By Allison Bond | August 31, 2009 4:23 pm

watermelonWatermelons could do more than grace the tables at picnics across the land: They could also serve as a source of biofuel. Researchers fermented watermelon juice to produce ethanol, according to a study published in Biotechnology for Biofuels, and while the melons aren’t likely to become a primary biofuel crop, the process could help out farmers.

Nearly one-fifth of the watermelon crop grown in the United States is left in the fields after harvest because of defects on the melons’ rinds. “It’s not that there’s anything wrong with the melon on the inside, but our only method of judgment is the outside,” said [lead author] Wayne Fish [Greenwire]. Although farmers often till the abandoned melons into the soil, the value of the nutrients provided by this practice is much less than the overall cost to farmers of losing so much of their crop.

To test whether watermelon is a viable source of ethanol, the researchers brewed several experimental batches of the fruity fuel in the lab and optimized the process to produce about 23 gallons (87 liters) of ethanol from an acre’s worth of the unused fruit [National Geographic News]. Growers could use the ethanol themselves or, if they have a sizable enough crop, they could sell it. The researchers suggest that the most efficient way to harvest the melons’ renewable energy might be via traveling microbreweries, rather than carting tons of watermelons to one central brewing location.

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Image: flickr / Kanko*

CATEGORIZED UNDER: Environment, Technology
  • Art


  • NewEnglandBob

    But does it smell like watermelon as you drive down the road?

  • Mirza

    Great. Now vast tracts of land will be devoted to growing watermelons instead of rice or corn, and world food prices will go up again. Give up bio-diesel already.

  • http://discovermagazine.com BaldGeek

    Too bad Mirza and others miss the real point: Disgarded and rejected produce and other ‘trash’ can be turned into fuel or something else equally valuable. Keep up the good work! A whole business could be created processing rejected produce, what about Cantalopes or Pumpkins?! How many billion pumpkins are grown only to be used as decorations then disgarded? How about processing the billions of tons of grass clippings discarded by home owners and producing celluosic ethanol?

  • http://clubneko.net robot makes music

    This is like the only good idea for biofuels I’ve ever heard.

  • Brian

    What I want to know is will the tailpipe spit out seeds as you drive down the road?

  • Jimbo

    For a great deal of time I have enjoyed the idea of bacterial fermentaion for ethanol; both from easily obtainable sugars and from cellulosic sources once the appropriate enzymes are used. However, one troubling fact remains is that we’re still burning something- and the combustion of ethanol will produce CO2. In addition, if ethanol is used in autos the mileage is ~20% less and that means we will be burning more ethanol to go the same distance with gasoline. I am very excited about not using fossil fuels, but it seems that driving with ethanol is not the best option until we can find a way to capture the CO2.

  • http://TwoSistersArtandSoul Lisette Root

    How about some sort of decorative covering , wrapper, or sleeve which could hide purely cosmetic blemishes, so the food can be consumed rather than wasted. It seems like a huge waste of resources to do anything other than consuming perfectly good food, and watermelons are a huge water consuming fruit, so the waste seems excessive.

  • http://www.wickerpicnicbasket.org Wicker Picnic Basket

    Thats very interesting news! Not only are watermelons a good food source, they can also be used as fuel. I wonder what other uses they will come up for it next. Bike helmets, perhaps? 😀


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