For generations, cow manure was simply an unavoidable byproduct of running a dairy farm.
asserted
manure → run → farm
At Jordan Dairy Farms in Rutland, Massachusetts, however, it became something much more valuable: a source of electricity, heat, fertiliser and even animal bedding.
asserted
it → become → electricity
In 2011, the family-run dairy installed what it describes as the first agricultural anaerobic digester in Massachusetts.
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it → run → Massachusetts
The system uses microorganisms to break down manure and other organic waste in an oxygen-free environment, producing biogas that can be used to generate electricity.
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that → use → electricity
Randy Jordan, who runs the farm with his brother Brian, was looking for a way to deal with rising electricity costs.
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who → run → costs
Jordan Dairy Farms had hundreds of cows producing manure every day, and Jordan began exploring whether that waste could be converted into energy.
uncertain
waste → have → energy
By 2020, the system was saving the farm roughly $155,000 a year through heat, fertiliser, and bedding produced from what would otherwise have been waste.
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what → save → heat
How does a manure digester work?
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digester → work → ?
The science behind the system is based on a natural biological process.
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science → base → process
Organic material such as manure contains compounds that microorganisms can consume.
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microorganisms → contain → that
Inside an anaerobic digester, the material is kept without oxygen, allowing microbes to break it down and release a mixture of gases, including methane and carbon dioxide.
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microbes → keep → methane
The methane can then be burned to generate electricity and heat.
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methane → burn → electricity
At Jordan Dairy Farms, manure is not the only material entering the digester.
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manure → enter → digester
Food and beverage waste collected from businesses is mixed with the farm's manure, increasing the amount of organic material available for digestion.
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waste → collect → digestion
According to Vanguard Renewables, which operates the system, the farm's digester receives around 20,000 tons of food waste and 9,125 tons of manure every year.
uncertain
digester → accord → manure
The material is processed inside a 500,000-gallon digestion tank.
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material → process → tank
Microorganisms break down the mixture, producing biogas that powers two engines.
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that → break → engines
Together, the engines have a capacity of about 800 kilowatts and generate approximately 4,200 megawatt-hours of renewable electricity annually, according to Vanguard.
uncertain
engines → have → Vanguard
Manure becomes electricity, heat and fertiliser
The process produces several useful outputs, turning one waste stream into multiple resources for the farm.
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process → become → farm
The electricity generated by the system can be used on the farm, while excess power has also been sold directly to nearby businesses.
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power → generate → businesses
The heat generated during the process is another important benefit.
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heat → generate → process
In 2020, Jordan told The Washington Post that heat and hot water produced by the digester saved the farm around $35,000 a year.
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heat → tell → 35,000
The farm also receives a huge volume of liquid fertiliser from the digestion process.
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farm → receive → process
Jordan said at the time that the system produced about 14 million gallons of liquid fertiliser annually, saving the farm roughly $100,000 in fertiliser costs.
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system → say → costs
The solid material left behind could also be used as animal bedding, providing another estimated $20,000 in annual savings.
uncertain
material → leave → savings
Together, those savings amounted to around $155,000 a year.
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savings → amount → 155,000
The current project information from Vanguard similarly lists reduced energy costs, low-carbon fertiliser, heat reuse, reduced chemical fertiliser use and odour reduction among the farm's benefits.
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information → list → benefits
The idea of putting food waste into a manure digester was particularly important to the project's economics.
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idea → put → economics
When Jordan first investigated digesters, the technology had already existed for decades.
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technology → investigate → decades
But many earlier systems struggled financially and operationally.
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systems → struggle → ?
According to The Washington Post, energy consultant Bill Jorgenson proposed combining food waste with manure.
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Jorgenson → accord → manure
The additional organic material could increase energy production, while companies looking to dispose of food waste could pay fees to have that material processed.
uncertain
material → increase → fees
That created a second revenue stream around the same piece of infrastructure.
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That → create → infrastructure
The arrangement also addressed another environmental problem: organic waste sent to landfills can generate methane as it decomposes.
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it → address → methane
Capturing organic material in a controlled digester instead allows much of that methane to be collected and used.
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much → capture → methane
For the farm, waste from food processors and other businesses becomes an input rather than something with no value.
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waste → become → value
What happens to the methane?
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What → happen → methane
The biogas produced by the digester contains methane, which is the component used to generate energy.
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which → produce → energy
At Jordan Dairy Farms, the gas is directed to generators that produce electricity.
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that → direct → electricity
The heat produced in the process can also be recovered and used around the farm.
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heat → produce → farm
…and 4 more, not listed.
The Aporia
