Put Bio Diesel in your backup generator? By Doug Mohney

Views and Opinions on Green IT (Oct 22 2009) Power and Cooling , Biomass

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   Diesel generators are the stock-in-trade of the majority of backup power solutions for data centers around the globe.  Some companies have smelled the French fries, so to speak, and have started buying generators tweaked (just a little) for specifically burning biodiesel.  Others are comfortable, with the right supplier, using a biodiesel blend as a drop-in replacement for the petroleum-based product.

    Bio-diesel is a fuel derived from any natural fat or oil and designed to burn in (what else?) a diesel engine. Every couple of months you have probably come across the cliché' story of a diesel vehicle – Mercedes-Benz cars seem to be a favorite – being run on a product derived from used cooking oil from the local fast food restaurants that, when burned, gives off the smell of whatever food was cooked in it.  

    Unless you are dealing with the breakdown of civilization, you probably don't want bio-diesel made in some guy's backyard home-brew rig, but want to use a commercial-grade product meeting national tech fuel specs, such as ASTM D 6751 or the European equivalent. Biodiesel is also blended with regular diesel to cut down the emissions of sulfur oxides, carbon monoxide and particulate matter of "regular" diesel; the B20 blend (20 percent biodiesel, 80 percent diesel) is a popular blend for vehicle fuel in the U.S. since it requires no modifications of a diesel engine or fuel system.

    Finding a local suppler of biodiesel in the U.S. is as easy as visiting www.biodiesel.org. Commercial-grade biodiesel is available in all 50 states and available through over 1,000 distributors.

   
   

   There are a few caveats in making a switch to biodiesel for a backup generator.  Most manufacturers support up to 5 percent biodiesel use without voiding the warranty on fuel-related components and others are moving to approve higher blends.  Manufacturers also warn of problems with spoilage if straight biodiesel or biodiesel blends sit around unused for more than three months, including problems with wader condensation and the potential for algae growth.

   
   

   (This gets into a "How often are you testing/running your generator?" issue. Regular operation shouldn't cause a problem, but letting biodiesel sit in a tank for six months seems to be asking for trouble – but then again, not testing a backup generator on a monthly basis might not be smart either, regardless of what you are feeding it).

   
   

   Burning biodiesel has a "cleansing effect" that may end up cleaning up accumulated deposits on tank walls and pipes from previous diesel fuel usage, so fuel filters should be checked more frequently upon first usage.  Biodiesel will also gel in cold weather, just like regular diesel fuel, so some caution may be required by treating it with cold weather additives and/or using other methods to keep the fuel warm.  That said, biodiesel is used year-round in such colder places as Colorado's Aspen resorts, Brooklyn Park, Minnesota and Yellowstone National Park.

   
   

   
   

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