A “Farm Powered” Business Model for Scalable Renewable Energy Production From Waste
It has been pointed out that “waste is only really waste if you waste it.” That is of particular concern when what is being wasted is potential renewable energy. Our food system generates two major waste streams that have traditionally ended up on the negative side of their potential – the manure that comes from farm animals, and the inedible food waste that happens at the food manufacturing or retail level. There is a solution that addresses both of these missed opportunities and reduces our reliance on landfills and incinerators. A company called Vanguard Renewables has developed a business model that connects farms with food companies and retailers to combine their waste streams and use them to generates renewable natural gas which can then serve to decarbonize the energy supply for society as a whole.
This solution hinges on a technology called “anaerobic digestion” or AD that has been used extensively for decades in Europe. An organic waste source like manure is put within a closed tank without oxygen. Under that “anaerobic” condition there are specialized microbes from the gut of the cow that can digest the organic matter. Unlike most living things that generate carbon dioxide as they metabolize their food, these “anaerobic” specialists generate methane gas - the same energy-rich fuel we call natural gas. The difference between the gas from one of these digesters and the fossil fuel version is that the carbon in the gas from a digester was created biologically, and not by fossil extraction. That means that when the methane is burned to produce energy, the carbon dioxide that is emitted is “carbon negative” and isn’t a net contributor to the total amount of CO2 in the atmosphere. Then, if the methane from a digester (also called “green natural gas”) is piped into the existing natural gas utility stream, it has the same sort of “decarbonization” effect that is achieved by putting electricity generated by solar, wind or nuclear into the overall electricity grid.