Cow Power

Posted on October 12, 2015 by Dr. Lynda

Have you heard of Cow PowerTM  yet? It’s the brilliant concept of creating power from cow manure!

This ingenious idea of turning something dairy farmers have a lot of – cow manure – into usable power for the farms and their neighbors could transform our ideas about farming and renewable energy.

We’ll get to the details, but in the simplest terms, it’s a way of generating power from cow manure, an ingenious process that’s a win for farmers, consumers, and the planet.The biofuel, or biogas to be specific, created by manure is one of the best examples of creative problem solving to gain traction in the recent eco-friendly movement.

We love this concept because it’s one of those innovations where excess and need intersect in perfect harmony: successful dairy farmers have an excess of cow waste, their neighbors need a better source of energy, and biofuel serves both masters with hardly a hiccup, and even a few bonuses to boot.

Liesl Grandpa Funeral-fall 09 359
This is one of many dairy cows nearby EWC headquarters in Fairfield, Vermont, but there are many, many like her leaving pounds of potential, incredibly beneficial energy behind.

Here’s a little background for you in case it’s been a while since you’ve been on the farm.

Manure lagoon that could be used to create power from cow manureIn many dairy states like Vermont, spreading manure on the fields is the primary way of keeping pastures lush and fertile. Unfortunately, over fertilizing or spreading manure before it rains causes most of the organic material to wind up in watersheds, destroying local water quality. Some fiscally conservative farms go so far as to store their own waste in a huge disposal bogs that release a tremendous amount of methane.

What’s wrong with methane? Well, most people don’t know that methane is up to 20 times more damaging to our planet’s ozone layer than CO2.  Each year 74 teragrams (1 Tg = 1012 grams or 16,314,207,401.68094 pounds) of methane is released into the air by domesticated animals alone! 1

But is it really “waste” if we don’t waste it? Take a look at this excellent video on how we can create power from cow manure:

Estimates from Science and Children state that methane-derived biogas in America might be capable of producing 100 billion kilowatt-hours of power. To put that in perspective, a typical 500-megawatt coal power plant produces 3.5 billion kWh per year, so if, in just the United States, farm cows’ manure was being harnessed for a methane power we could reduce the emissions from around 25 coal plants. The end result would easily reduce greenhouse gas emissions from the use of fossil fuels and methane decomposition in bogs by 99 million metric tons. 3

When it’s viewed in sheer numbers, the whole idea of biogas seems to be a no-brainer: highly efficient, combustible energy source that would not only help the environment but allow farms across the world a chance at another source of much-needed income.

So, how’s it made?

It’s actually an interesting combination of Mother Nature’s way and scientific ingenuity. Here’s an info-graphic showing the overall procedure:

Image: Humboldt State University's anaerobic digester, how to generate power from cow manure

Remember when we mentioned all that methane that the manure bogs would let off? That methane is a product of what’s called anaerobic respiration. Essentially, tiny microorganisms break down the cow manure, using up all the remaining oxygen in their surroundings.Those microorganisms, in turn, release their own “waste,” which is methane. That process happens where ever organic material falls into stagnant water: swamps, bogs, deep ocean, perhaps a teenager’s bedroom.

To speed up the process, the enormous anaerobic digester on farms gets heated to several hundred degrees, allowing the methane to effectively cook. The manure separates releasing a gas to float upward. This methane is funneled into pipes, collected, and itself heated.

And this is where the magic happens: for each 1,000 kilograms of raw manure, methane output is up to 60 percent. In other words, a single cow can output 3-kilowatt hours of energy per day… one cow. 4

It’s practically a black and white issue!

So where are we so far?

Now that you’ve got an idea of how we can generate power from cow manure, let’s summarize what we have learned:

  1. One cow can leave 3-kilowatt hours’-worth of waste per day. Wow! That’s enough energy to do 12 pounds (5 kilos) of laundry, or to run your computer or a 100 watt light bulb for 30 hours! (That’s according to a great list produced by Duke Energy. You can look at it by clicking here.)
  2. Cows in America alone are capable of 100 billion kilowatt hours of energy
  3. The would-be wasted methane is no longer depleting the ozone layer
  4. Farmers, earn money from power companies and save money on waste removal fees.

Image: Black and white cow, power from cow manureIs there any waste in the system?

My first thought was “well what about the 40 percent (or 300kg per 1,000kg) of unused solid waste product?”

And this is where biogas really shines.

See, that 40 percent is divided into two parts: a liquid component and a solid component. The liquid component is incredibly rich in nitrogen (N20), and can be used as a comparable fertilizer to the original, undigested manure.

But the solid? Well, that’s the miracle of Mother Nature I noted early on. The solid remains can be used for everything from natural weed killer to safe, totally sanitized (thanks to the digester’s heating process) bedding for the very cows it came from (among other animals). The latter is yet another huge savings for the farms, too: many farms spend thousands on bedding for their herd, normally in the form of sawdust.

Suddenly… we see what is popularly called a Closed Loop Cycle: a system that is sustainable with no waste. Genius!

Have you read much about this “Closed Loop” recycling or the people who live to have less than one mason jar full of garbage in a full year?! If you enjoyed this tale of how we can get power from cow manure, here’s the next article you would love if making a better world inspires you. Here’s a link to our article called How Far is Away, an amazing, fun eye-opener. It’s written by an EWC guest-writer (you can do that too!.. submit a simple link or a written piece!) who shared with us an extraordinary life-style that is catching on.

Meanwhile, do your best to keep a sense of wonder going. There’s plenty of it here among our 300+ articles. You can head to our older posts, or scroll down to the bottom of this article to see 6 others I recommend.

Stay open, curious and hopeful!

~ Dr. Lynda