Written by: Kimberly White
Summer is over and Fall has begun. With the change of season comes falling leaves, a cool breeze, and, of course, pumpkins. When one conjures up thoughts about the Fall season, pumpkins immediately come to mind. The United States produces approximately 1.3 billion pounds of pumpkins every year. We carve them for Halloween decorations and make pumpkin pie, but what happens to them once Halloween is over? Most of the 1.3 billion end up being thrown into a landfill or a compost pile. That is a lot of pumpkins being thrown into landfills when they can be turned into something much more efficient than a rotting gourd! According to the U.S. Department of Energy’s Matthew Loveless, Oakland, Ca. has an alternative. The East Bay Municipal District (EBMUD) is using food waste, including pumpkins, as a source of renewable electricity.
The East Bay Municipal Utility District uses waste haulers to gather food waste. From there the waste is placed in with the anaerobic digesters. EBMUD uses giant tanks filled with bacteria in order to break down the food waste. Once the food waste is broken down, it releases methane gas. After the methane gas is released, EBMUD captures it and uses it in order to power their onsite generators. One ton of food waste creates about 367 cubic meters of gas. Loveless stated, “…digesting 100 tons of food wastes five days a week can generate enough electricity to power 1000 homes.” If five-hundred tons of food waste can produce enough electricity to power a thousand homes, think about how much can be generated on the pumpkins alone. 1.3 billion pounds is equivalent to 650,000 tons, which means that the discarded pumpkins each year have the possibility of producing enough power for 1.3 million homes. A much better alternative than if they were merely sitting in a landfill.
Once the food waste is converted by the anaerobic process, the remaining solids can be useful, too. The remaining solids can be used to make a natural fertilizer to be used on the next year’s crops. This use would really bring the whole process full-circle: the pumpkins are grown, used, discarded, converted to energy, and then used as fertilizer for the next ge
neration of pumpkins.
Electricity isn’t the only alternative for these festive gourds, they can also be used to create biofuels. As they, and other waste, decompose they turn into methane. Methane can cause twenty times the warming of carbon dioxide, but can be harnessed into an environmentally-friendly fuel. Using the byproducts of waste to come up with an alternative fuel would allow the U.S. to generate clean energy, reduce greenhouse gases, reduce dependence on carbon-based fuel and reduce the amount of waste that goes into our landfills. Biofuels produced from waste are a more sustainable option than those that are grown from crops. According to Greenpeace, “Investments should go into truly sustainable biofuels, such as those produced from waste, which do not require the use of land.”
Overall, it is very interesting to see alternatives for our food waste. If we can use the billions of discarded pumpkins from Halloween to power our homes or our cars, why not? It is much more energy efficient, cost-effective, and helps reduce our footprint on the planet. Biofuels made from food waste are leading the way into the future, one pumpkin at a time.
References:
http://energy.gov/articles/pumpkin-power-turning-food-waste-energy
http://energy.gov/articles/turn-your-halloween-pumpkins-power
