When it comes to watermelon farming, 20 to 40 percent of the crops are left unsold due to irregularities (such as bird pecks) that keep them from passing quality control. According to Discovery, 360,000 tons of watermelons remain unsold after every harvesting in the United States alone. In a series of experiments conducted by Wayne Fish of the United States Department of Agriculture in Lane, Oklahoma and a team of researchers, it was proven that watermelon could well help with biofuel production. The watermelons by themselves could produce around 2.5 million gallons of ethanol per annum. The real possibility of widespread watermelon use in the biofuel industry though lies in its potential to serve as one of the components of other biofuel feedstocks such as corn.
"This is not going to replace corn. In that sense it will remain a niche source of biofuel," said Jim Rausch, president of the College Station, Texas-based company Common Sense Agriculture, LLC, which is developing a prototype watermelon juice-to-ethanol processing plant."But unlike algae biodiesel or cellulosic ethanol, it's a right now thing. There's no new technology that needs to be developed to make it economical."
Watermelon juice is full of amino acids besides the 10 percent sugar content. These amino acids can be rich source of nitrogen that can be used for fermentation. And since production of corn biofuel requires lots of water and nitrogen for fermentation, watermelon juice could be used as an alternative to both. This will lead to a reduction in water use and nitrogen source purchase, even cutting down feedstock requirement by 15 percent due to the fruits' sugar content.