Halloween might be over, but pumpkins can still be put to good use.
“The best way to do it is to take the pumpkins and put them in your green bin at your home and that way it can go to a good use after Halloween and we can make renewable energy and compost out of it,” said Thomas Gratz, the sales manager for Hitachi Zosen Inova U.S.A. located in San Luis Obispo.
At Hitachi Zosen Inova. the pumpkins and other organic material are put through a digestion system that makes renewable energy as well as compost.
“We are putting these pumpkins in our anaerobic digestion system that produces methane gas and internally then also renewable energy in the form of electricity,” said Gratz.
The biogas is used in the engine to produce renewable electricity and is fed through the PG&E power grid and can produce enough electricity for about 600 homes.
What is leftover after that process turns into certified organic compost.
“Typically during pumpkin season, the nice part is that the green waste starts going down because it's the end of the season and we can substitute that with pumpkins and then ultimately Christmas trees,” Gratz added.
The facility churns out about 30 tons of compost every day.
“People use that in their yards or on vineyards and farm fields to add to the soil and make the soil more able to retain moisture and also bring nutrients back to the soil," said Gatz. Candles, metals, and other inorganic materials should not be thrown in green waste bins because it can interrupt the process.
The facility hosts a public compost giveaway in the spring and fall each year. People can bring buckets or even pickup trucks.
Integrated Waste Management Authority also offers other suggestions for pumpkins that include using it as a snack for backyard chickens, putting birdseed inside it as a birdfeeder, or using it as compost for your own yard.