In the second entry of our Resource Recovery Series, we look into the benefits of co-digestion.
Anaerobic Digesters are expensive systems. Many experts say that in order to have enough capacity to generate a sufficient amount of energy to make profit, you are looking at a start-up cost of at least $5 million.
This is not to say that Anaerobic Digesters are an unwise investment. Rather, it is a matter of being able to balance the large start-up investment with the various means of generating revenue from the system. Another vital factor is being able to utilize the system’s full capacity so that energy production is maximized. In cases where additional capacity is available and the tank is “half-empty”, users look to incorporate additional sources of organic waste such as food scraps, processing pulps and fats-oils-greases (FOG). This is known as co-digestion.
According to Waste Management, Inc., 60 million tons of food is wasted annually in the U.S. at a cost of over $160 million, making up almost 30% of the entire waste stream. This leaves a large market share to incorporate food waste as co-digestion feedstock. Revenue can be generated via energy production in the form of natural gas, and tip fees associated with managing this waste stream.
Not only is co-digestion a means to bring in additional revenue from waste disposal fees (also known as tip fees), but incorporating specific types of organic waste into a system can actually add substantial value in energy production. In fact, many of these sources can bring more energy value than the primary feedstock, being either manure or wastewater sludge.
For Anaerobic Digesters with residual capacity, co-digestion adds substantial value to your system by utilizing full capacity, resulting in maximum revenue output. We at BCS continue to look for ways to optimize your systems as we continue “putting the pieces together.”